Chloroplasts: Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.DNA, Chloroplast: Deoxyribonucleic acid that makes up the genetic material of CHLOROPLASTS.Chloroplast Proteins: Proteins encoded by the CHLOROPLAST GENOME or proteins encoded by the nuclear genome that are imported to and resident in the CHOROPLASTS.Genome, Chloroplast: The genetic complement of CHLOROPLASTS as represented in their DNA.RNA, Chloroplast: Ribonucleic acid in chloroplasts having regulatory and catalytic roles as well as involvement in protein synthesis.Genes, Chloroplast: Those nucleic acid sequences that function as units of heredity which are located within the CHLOROPLAST DNA.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Euglena gracilis: A species of fresh-water, flagellated EUKARYOTES in the phylum EUGLENIDA.Peas: A variable annual leguminous vine (Pisum sativum) that is cultivated for its rounded smooth or wrinkled edible protein-rich seeds, the seed of the pea, and the immature pods with their included seeds. (From Webster's New Collegiate Dictionary, 1973)Photosynthesis: The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Spinacia oleracea: A widely cultivated plant, native to Asia, having succulent, edible leaves eaten as a vegetable. (From American Heritage Dictionary, 1982)Thylakoids: Membranous cisternae of the CHLOROPLAST containing photosynthetic pigments, reaction centers, and the electron-transport chain. Each thylakoid consists of a flattened sac of membrane enclosing a narrow intra-thylakoid space (Lackie and Dow, Dictionary of Cell Biology, 2nd ed). Individual thylakoids are interconnected and tend to stack to form aggregates called grana. They are found in cyanobacteria and all plants.Chlamydomonas reinhardtii: A species of GREEN ALGAE. Delicate, hairlike appendages arise from the flagellar surface in these organisms.Plastids: Self-replicating cytoplasmic organelles of plant and algal cells that contain pigments and may synthesize and accumulate various substances. PLASTID GENOMES are used in phylogenetic studies.Chloroplast Proton-Translocating ATPases: Proton-translocating ATPases which produce ADENOSINE TRIPHOSPHATE in plants. They derive energy from light-driven reactions that develop high concentrations of protons within the membranous cisternae (THYLAKOIDS) of the CHLOROPLASTS.Chlorophyll: Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.Chloroplast Thioredoxins: A subtype of thioredoxins found primarily in CHLOROPLASTS.Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)Arabidopsis Proteins: Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Ribulose-Bisphosphate Carboxylase: A carboxy-lyase that plays a key role in photosynthetic carbon assimilation in the CALVIN-BENSON CYCLE by catalyzing the formation of 3-phosphoglycerate from ribulose 1,5-biphosphate and CARBON DIOXIDE. It can also utilize OXYGEN as a substrate to catalyze the synthesis of 2-phosphoglycolate and 3-phosphoglycerate in a process referred to as photorespiration.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Chlamydomonas: A genus GREEN ALGAE in the order VOLVOCIDA. It consists of solitary biflagellated organisms common in fresh water and damp soil.Chlorophyta: A phylum of photosynthetic EUKARYOTA bearing double membrane-bound plastids containing chlorophyll a and b. They comprise the classical green algae, and represent over 7000 species that live in a variety of primarily aquatic habitats. Only about ten percent are marine species, most live in freshwater.Photosynthetic Reaction Center Complex Proteins: Protein complexes that take part in the process of PHOTOSYNTHESIS. They are located within the THYLAKOID MEMBRANES of plant CHLOROPLASTS and a variety of structures in more primitive organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.Photophosphorylation: The use of light to convert ADP to ATP without the concomitant reduction of dioxygen to water as occurs during OXIDATIVE PHOSPHORYLATION in MITOCHONDRIA.Photosystem II Protein Complex: A large multisubunit protein complex found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN.Plants, Medicinal: Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.Genes, Plant: The functional hereditary units of PLANTS.Fabaceae: The large family of plants characterized by pods. Some are edible and some cause LATHYRISM or FAVISM and other forms of poisoning. Other species yield useful materials like gums from ACACIA and various LECTINS like PHYTOHEMAGGLUTININS from PHASEOLUS. Many of them harbor NITROGEN FIXATION bacteria on their roots. Many but not all species of "beans" belong to this family.Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.Galactolipids: A group of GLYCOLIPIDS in which the sugar group is GALACTOSE. They are distinguished from GLYCOSPHINGOLIPIDS in lacking nitrogen. They constitute the majority of MEMBRANE LIPIDS in PLANTS.Euglena: A genus of EUKARYOTES, in the phylum EUGLENIDA, found mostly in stagnant water. Characteristics include a pellicle usually marked by spiral or longitudinal striations.Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Algal Proteins: Proteins found in any species of algae.Darkness: The absence of light.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Light-Harvesting Protein Complexes: Complexes containing CHLOROPHYLL and other photosensitive molecules. They serve to capture energy in the form of PHOTONS and are generally found as components of the PHOTOSYSTEM I PROTEIN COMPLEX or the PHOTOSYSTEM II PROTEIN COMPLEX.Cytochrome b6f Complex: A protein complex that includes CYTOCHROME B6 and CYTOCHROME F. It is found in the THYLAKOID MEMBRANE and plays an important role in process of PHOTOSYNTHESIS by transferring electrons from PLASTOQUINONE to PLASTOCYANIN or CYTOCHROME C6. The transfer of electrons is coupled to the transport of PROTONS across the membrane.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.RNA, Plant: Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.Intracellular Membranes: Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Eukaryota: One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.Proton-Translocating ATPases: Multisubunit enzymes that reversibly synthesize ADENOSINE TRIPHOSPHATE. They are coupled to the transport of protons across a membrane.Cytochromes f: Cytochromes f are found as components of the CYTOCHROME B6F COMPLEX. They play important role in the transfer of electrons from PHOTOSYSTEM I to PHOTOSYSTEM II.Plants, Toxic: Plants or plant parts which are harmful to man or other animals.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.Mesophyll Cells: Large and highly vacuolated cells possessing many chloroplasts occuring in the interior cross-section of leaves, juxtaposed between the epidermal layers.Diuron: A pre-emergent herbicide.Plants, Edible: An organism of the vegetable kingdom suitable by nature for use as a food, especially by human beings. Not all parts of any given plant are edible but all parts of edible plants have been known to figure as raw or cooked food: leaves, roots, tubers, stems, seeds, buds, fruits, and flowers. The most commonly edible parts of plants are FRUIT, usually sweet, fleshy, and succulent. Most edible plants are commonly cultivated for their nutritional value and are referred to as VEGETABLES.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Photosystem I Protein Complex: A large multisubunit protein complex that is found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to drive electron transfer reactions that result in either the reduction of NADP to NADPH or the transport of PROTONS across the membrane.Acetabularia: A genus of green algae found in the Mediterranean and other warm seas.Hordeum: A plant genus of the family POACEAE. The EDIBLE GRAIN, barley, is widely used as food.RNA Editing: A process that changes the nucleotide sequence of mRNA from that of the DNA template encoding it. Some major classes of RNA editing are as follows: 1, the conversion of cytosine to uracil in mRNA; 2, the addition of variable number of guanines at pre-determined sites; and 3, the addition and deletion of uracils, templated by guide-RNAs (RNA, GUIDE).Protein PrecursorsPlastoquinone: Polyunsaturated side-chain quinone derivative which is an important link in the electron transport chain of green plants during the photosynthetic conversion of light energy by photophosphorylation into the potential energy of chemical bonds.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Angiosperms: Members of the group of vascular plants which bear flowers. They are differentiated from GYMNOSPERMS by their production of seeds within a closed chamber (OVARY, PLANT). The Angiosperms division is composed of two classes, the monocotyledons (Liliopsida) and dicotyledons (Magnoliopsida). Angiosperms represent approximately 80% of all known living plants.Protein Transport: The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.RNA, Algal: Ribonucleic acid in algae having regulatory and catalytic roles as well as involvement in protein synthesis.Fructose-Bisphosphatase: An enzyme that catalyzes the conversion of D-fructose 1,6-bisphosphate and water to D-fructose 6-phosphate and orthophosphate. EC 3.1.3.11.Plastocyanin: A copper-containing plant protein that is a fundamental link in the electron transport chain of green plants during the photosynthetic conversion of light energy by photophosphorylation into the potential energy of chemical bonds.Group I Chaperonins: A subcategory of chaperonins found in MITOCHONDRIA; CHLOROPLASTS; and BACTERIA. Group I chaperonins form into a barrel-shaped macromolecular structure that is enclosed by a separate lid-like protein component.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)Bryopsida: A class of plants within the Bryophyta comprising the mosses, which are found in both damp (including freshwater) and drier situations. Mosses possess erect or prostrate leafless stems, which give rise to leafless stalks bearing capsules. Spores formed in the capsules are released and grow to produce new plants. (Concise Dictionary of Biology, 1990). Many small plants bearing the name moss are in fact not mosses. The "moss" found on the north side of trees is actually a green alga (CHLOROPHYTA). Irish moss is really a red alga (RHODOPHYTA). Beard lichen (beard moss), Iceland moss, oak moss, and reindeer moss are actually LICHENS. Spanish moss is a common name for both LICHENS and an air plant (TILLANDSIA usneoides) of the pineapple family. Club moss is an evergreen herb of the family LYCOPODIACEAE.Protochlorophyllide: A photo-active pigment localized in prolamellar bodies occurring within the proplastids of dark-grown bean leaves. In the process of photoconversion, the highly fluorescent protochlorophyllide is converted to chlorophyll.RNA, Ribosomal: The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Ferredoxins: Iron-containing proteins that transfer electrons, usually at a low potential, to flavoproteins; the iron is not present as in heme. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Rhodophyta: Plants of the division Rhodophyta, commonly known as red algae, in which the red pigment (PHYCOERYTHRIN) predominates. However, if this pigment is destroyed, the algae can appear purple, brown, green, or yellow. Two important substances found in the cell walls of red algae are AGAR and CARRAGEENAN. Some rhodophyta are notable SEAWEED (macroalgae).Protein Biosynthesis: The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.Plant Physiological Phenomena: The physiological processes, properties, and states characteristic of plants.Thioredoxins: Hydrogen-donating proteins that participates in a variety of biochemical reactions including ribonucleotide reduction and reduction of PEROXIREDOXINS. Thioredoxin is oxidized from a dithiol to a disulfide when acting as a reducing cofactor. The disulfide form is then reduced by NADPH in a reaction catalyzed by THIOREDOXIN REDUCTASE.Cyanobacteria: A phylum of oxygenic photosynthetic bacteria comprised of unicellular to multicellular bacteria possessing CHLOROPHYLL a and carrying out oxygenic PHOTOSYNTHESIS. Cyanobacteria are the only known organisms capable of fixing both CARBON DIOXIDE (in the presence of light) and NITROGEN. Cell morphology can include nitrogen-fixing heterocysts and/or resting cells called akinetes. Formerly called blue-green algae, cyanobacteria were traditionally treated as ALGAE.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Ferredoxin-NADP Reductase: An enzyme that catalyzes the oxidation and reduction of FERREDOXIN or ADRENODOXIN in the presence of NADP. EC 1.18.1.2 was formerly listed as EC 1.6.7.1 and EC 1.6.99.4.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Phototropins: Blue-light receptors that regulate a range of physiological responses in PLANTS. Examples include: PHOTOTROPISM, light-induced stomatal opening, and CHLOROPLAST movements in response to changes in light intensity.DNA, Algal: Deoxyribonucleic acid that makes up the genetic material of algae.Ribosomal Proteins: Proteins found in ribosomes. They are believed to have a catalytic function in reconstituting biologically active ribosomal subunits.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Plant Cells: Basic functional unit of plants.Mustard Plant: Any of several BRASSICA species that are commonly called mustard. Brassica alba is white mustard, B. juncea is brown or Chinese mustard, and B. nigra is black, brown, or red mustard. The plant is grown both for mustard seed from which oil is extracted or used as SPICES, and for its greens used as VEGETABLES or ANIMAL FEED. There is no relationship to MUSTARD COMPOUNDS.Starch: Any of a group of polysaccharides of the general formula (C6-H10-O5)n, composed of a long-chain polymer of glucose in the form of amylose and amylopectin. It is the chief storage form of energy reserve (carbohydrates) in plants.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Mitochondria: Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)Cytochrome b Group: Cytochromes (electron-transporting proteins) with protoheme (HEME B) as the prosthetic group.Ascorbate Peroxidases: Peroxidases that utilize ASCORBIC ACID as an electron donor to reduce HYDROGEN PEROXIDE to WATER. The reaction results in the production of monodehydroascorbic acid and DEHYDROASCORBIC ACID.Kinetics: The rate dynamics in chemical or physical systems.Molecular Weight: The sum of the weight of all the atoms in a molecule.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Seedling: Very young plant after GERMINATION of SEEDS.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Introns: Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Protein Sorting Signals: Amino acid sequences found in transported proteins that selectively guide the distribution of the proteins to specific cellular compartments.Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Bryophyta: A division of the plant kingdom. Bryophyta contains the subdivision, Musci, which contains the classes: Andreaeopsida, BRYOPSIDA, and SPHAGNOPSIDA.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.ATP Synthetase Complexes: Multisubunit enzyme complexes that synthesize ADENOSINE TRIPHOSPHATE from energy sources such as ions traveling through channels.Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.Phototropism: The directional growth of organisms in response to light. In plants, aerial shoots usually grow towards light. The phototropic response is thought to be controlled by auxin (= AUXINS), a plant growth substance. (From Concise Dictionary of Biology, 1990)Adiantum: A plant genus of the family Pteridaceae. Members contain TRITERPENES. Some species in this genus are called maidenhair fern which is also a common name occasionally used for Lygodium (FERNS) and POLYPODIUM.

Magnesium ion-induced changes in the binding mode of adenylates to chloroplast coupling factor 1. (1/4503)

The effect of Mg2+ on the binding of adenylates to isolated chloroplast coupling factor 1 (CF1) was studied using CD spectrometry and ultrafiltration. At adenylate concentrations smaller than 100 muM, one mole of CF1 binds three moles of ATP (or ADP) regardless of the presence of Mg2+. In the presence of Mg2+, the first two ATP's bind to CF1 independently with the same binding constant of 2.5 X 10(-1) muM-1, then the third ATP binds with a much higher affinity of 10 muM-1. In the absence of Mg2+, the first ATP binds to CF1 with a binding constant of 2.5 X 10(-1) muM-1 then the other two ATP's bind less easily with the same binding constant of 4.0 X 10(-2) muM-1. The binding mode of ADP to CF1 is quite similar to that of ATP. In the presence of Mg2+, the binding constants of the first two ADP's are both 7.6 X 10(-2) muM-1, that of the third ADP being 4.0 muM-1. In the absence of Mg2+, the binding constant of the first ADP is 7.6 X 10(-2) muM-1, the constants of the other two ADP's both being 4.0 X 10(-2) muM-1. AMP caused a negligible change in CD.  (+info)

Role of a novel photosystem II-associated carbonic anhydrase in photosynthetic carbon assimilation in Chlamydomonas reinhardtii. (2/4503)

Intracellular carbonic anhydrases (CA) in aquatic photosynthetic organisms are involved in the CO2-concentrating mechanism (CCM), which helps to overcome CO2 limitation in the environment. In the green alga Chlamydomonas reinhardtii, this CCM is initiated and maintained by the pH gradient created across the chloroplast thylakoid membranes by photosystem (PS) II-mediated electron transport. We show here that photosynthesis is stimulated by a novel, intracellular alpha-CA bound to the chloroplast thylakoids. It is associated with PSII on the lumenal side of the thylakoid membranes. We demonstrate that PSII in association with this lumenal CA operates to provide an ample flux of CO2 for carboxylation.  (+info)

The localisation of 2-carboxy-D-arabinitol 1-phosphate and inhibition of Rubisco in leaves of Phaseolus vulgaris L. (3/4503)

A recent controversial report suggests that the nocturnal inhibitor of Rubisco, 2-carboxy-D-arabinitol 1-phosphate (CAIP), does not bind to Rubisco in vivo and therefore that CA1P has no physiological relevance to photosynthetic regulation. It is now proved that a direct rapid assay can be used to distinguish between Rubisco-bound and free CA1P, as postulated in the controversial report. Application of this direct assay demonstrates that CA1P is bound to Rubisco in vivo in dark-adapted leaves. Furthermore, CA1P is shown to be in the chloroplasts of mesophyll cells. Thus, CA1P does play a physiological role in the regulation of Rubisco.  (+info)

Overexpression of the Bacillus thuringiensis (Bt) Cry2Aa2 protein in chloroplasts confers resistance to plants against susceptible and Bt-resistant insects. (4/4503)

Evolving levels of resistance in insects to the bioinsecticide Bacillus thuringiensis (Bt) can be dramatically reduced through the genetic engineering of chloroplasts in plants. When transgenic tobacco leaves expressing Cry2Aa2 protoxin in chloroplasts were fed to susceptible, Cry1A-resistant (20,000- to 40,000-fold) and Cry2Aa2-resistant (330- to 393-fold) tobacco budworm Heliothis virescens, cotton bollworm Helicoverpa zea, and the beet armyworm Spodoptera exigua, 100% mortality was observed against all insect species and strains. Cry2Aa2 was chosen for this study because of its toxicity to many economically important insect pests, relatively low levels of cross-resistance against Cry1A-resistant insects, and its expression as a protoxin instead of a toxin because of its relatively small size (65 kDa). Southern blot analysis confirmed stable integration of cry2Aa2 into all of the chloroplast genomes (5, 000-10,000 copies per cell) of transgenic plants. Transformed tobacco leaves expressed Cry2Aa2 protoxin at levels between 2% and 3% of total soluble protein, 20- to 30-fold higher levels than current commercial nuclear transgenic plants. These results suggest that plants expressing high levels of a nonhomologous Bt protein should be able to overcome or at the very least, significantly delay, broad spectrum Bt-resistance development in the field.  (+info)

EPR spectroscopy of VO2+-ATP bound to catalytic site 3 of chloroplast F1-ATPase from Chlamydomonas reveals changes in metal ligation resulting from mutations to the phosphate-binding loop threonine (betaT168). (5/4503)

Site-directed mutations were made to the phosphate-binding loop threonine in the beta-subunit of the chloroplast F1-ATPase in Chlamydomonas (betaT168). Rates of photophosphorylation and ATPase-driven proton translocation measured in coupled thylakoids purified from betaT168D, betaT168C, and betaT168L mutants had <10% of the wild type rates, as did rates of Mg2+-ATPase activity of purified chloroplast F1-ATPase (CF1). The EPR spectra of VO2+-ATP bound to Site 3 of CF1 from wild type and mutants showed that EPR species C, formed exclusively upon activation, was altered in CF1 from each mutant in both signal intensity and in 51V hyperfine parameters that depend on the equatorial VO2+ ligands. These data provide the first direct evidence that Site 3 is a catalytic site. No significant differences between wild type and mutants were observed in EPR species B, the predominant form of the latent enzyme. Thus, the phosphate-binding loop threonine is an equatorial metal ligand in the activated conformation but not in the latent conformation of Site 3. The metal-nucleotide conformation that gives rise to species B is consistent with the Mg2+-ADP complex that becomes entrapped in a catalytic site in a manner that regulates enzymatic activity. The lack of catalytic function of CF1 with entrapped Mg2+-ADP may be explained in part by the absence of the phosphate-binding loop threonine as a metal ligand.  (+info)

The chloroplast infA gene with a functional UUG initiation codon. (6/4503)

All chloroplast genes reported so far possess ATG start codons and sometimes GTGs as an exception. Sequence alignments suggested that the chloroplast infA gene encoding initiation factor 1 in the green alga Chlorella vulgaris has TTG as a putative initiation codon. This gene was shown to be transcribed by RT-PCR analysis. The infA mRNA was translated accurately from the UUG codon in a tobacco chloroplast in vitro translation system. Mutation of the UUG codon to AUG increased translation efficiency approximately 300-fold. These results indicate that the UUG is functional for accurate translation initiation of Chlorella infA mRNA but it is an inefficient initiation codon.  (+info)

Rapid purification of membrane extrinsic F1-domain of chloroplast ATP synthase in monodisperse form suitable for 3D-crystallization. (7/4503)

A new chromatographic procedure for purification of the membrane extrinsic F1-domain of chloroplast ATP synthase is presented. The purification is achieved by a single anion exchange chromatography step. Determination of the enzyme-bound nucleotides reveals only 1 mole of ADP per complex. The purified enzyme shows a latent Ca(2+)-dependent ATPase activity of 1.0 mumol.mg-1 min-1 and a Mg(2+)-dependent activity of 4.4 mumol.mg-1 .min-1. Both activities are increased up to 8-10-fold after dithiothreitol activation. Analysis of the purified F1-complex by SDS/PAGE, silver staining and immunoblotting revealed that the preparation is uncontaminated by fragmented subunits or ribulose-1,5-bisphosphate carboxylase/oxygenase. Gel filtration experiments indicate that the preparation is homogenous and monodisperse. In order to determine the solubility minimum of the purified F1-complex the isoelectric point of the preparation was calculated from pH mapping on ion exchange columns. In agreement with calculations based on the amino acid sequence, a slightly acidic pI of 5.7 was found. Using ammonium sulphate as a precipitant the purified CF1-complex could be crystallized by MicroBatch.  (+info)

Isolation of pigment-binding early light-inducible proteins from pea. (8/4503)

The early light-inducible proteins (ELIPs) in chloroplasts possess a high sequence homology with the chlorophyll a/b-binding proteins but differ from those proteins by their substoichiometric and transient appearance. In the present study ELIPs of pea were isolated by a two-step purification strategy: perfusion chromatography in combination with preparative isoelectric focussing. Two heterogeneous populations of ELIPs were obtained after chromatographic separation of solubilized thylakoid membranes using a weak anion exchange column. One of these populations contained ELIPs in a free form providing the first isolation of these proteins. To prove whether the isolated and pure forms of ELIP bind pigments, spectroscopic and chromatographic analysis were performed. Absorption spectra and TLC revealed the presence of chlorophyll a and lutein. Measurements of steady-state fluorescence emission spectra at 77 K exhibited a major peak at 674 nm typical for chlorophyll a bound to the protein matrix. The action spectrum of the fluorescence emission measured at 674 nm showed several peaks originating mainly from chlorophyll a. It is proposed that ELIPs are transient chlorophyll-binding proteins not involved in light-harvesting but functioning as scavengers for chlorophyll molecules during turnover of pigment-binding proteins.  (+info)

*Chloroplast

Some chloroplasts contain a structure called the chloroplast peripheral reticulum. It is often found in the chloroplasts of C4 ... Almost all chloroplasts in a cell divide, rather than a small group of rapidly dividing chloroplasts. Chloroplasts have no ... All chloroplasts have at least three membrane systems-the outer chloroplast membrane, the inner chloroplast membrane, and the ... Most dinophyte chloroplasts are secondary red algal derived chloroplasts. Many other dinophytes have lost the chloroplast ( ...

*Chloroplast DNA

... a histone-like chloroplast protein (HC) coded by the chloroplast DNA that tightly packs each chloroplast DNA ring into a ... Most chloroplasts have their entire chloroplast genome combined into a single large ring, though those of dinophyte algae are a ... Chloroplast DNAs have long been thought to have a circular structure, but some evidence suggests that chloroplast DNA more ... Protein synthesis within chloroplasts relies on an RNA polymerase coded by the chloroplast's own genome, which is related to ...

*Chloroplast membrane

Chloroplasts contain several important membranes, vital for their function. Like mitochondria, chloroplasts have a double- ... membrane envelope, called the chloroplast envelope, but unlike mitochondria, chloroplasts also have internal membrane ... The chloroplasts come via endosymbiosis by engulfment of a photosynthetic cyanobacterium by the eukaryotic, already ... The outer membrane is permeable to most ions and metabolites, but the inner membrane of the chloroplast is highly specialised ...

*Chloroplast capture

Chloroplast DNA variation within and among genera of the Heuchera group: evidence for extensive chloroplast capture and the ... Chloroplast capture is an evolutionary process through which inter-species hybridization and subsequent backcrosses yield a ... Chloroplast evolution in the Pinus montezumae complex: a coalescent approach to hybridization. Evolution 54: 1218-1233 ... For instance, 1) species A's (having chloroplast genome a and nuclear genome AA) pollen hybridizes (backcross) to species B's ( ...

*Chloroplast sensor kinase

... (CSK) is a protein in chloroplasts of green plants and algae. In the plant Arabidopsis thaliana ( ... CSK is intrinsic to chloroplasts, targeted to chloroplast genes, and may be required for the retention, in evolution, of ... The gene for CSK is found in cyanobacteria; prokaryotes from which chloroplasts evolved by endosymbiosis. CSK and its redox ... Journal of Theoretical Biology 165: 609-631 Allen JF (2015) Why chloroplasts and mitochondria retain their own genomes and ...

*Chloroplast protein-transporting ATPase

In enzymology, a chloroplast protein-transporting ATPase (EC 3.6.3.52) is an enzyme that catalyzes the chemical reaction ATP + ... Nakai M, Goto A, Nohara T, Sugita D, Endo T (1994). "Identification of the SecA protein homolog in pea chloroplasts and its ... The systematic name of this enzyme class is ATP phosphohydrolase (chloroplast protein-importing). Cline K, Ettinger WF, Theg SM ... Scott SV, Theg SM (1996). "A new chloroplast protein import intermediate reveals distinct translocation machineries in the two ...

*Evolution of molecular chaperones

Mitochondria were found to be most closely related to the α-purple subdivision of Gram negative bacteria and chloroplasts were ... Hsp10 and hsp60 are present in all eubacteria and organelles of eukaryotes (mitochondria and chloroplasts), but not in ... and chloroplasts. Any two hsp60 amino acid sequences share at least 40% similarity, with 18-20% of differences coming from ... support the current endosymbiosis model of the origin of mitochondria and chloroplasts. ...

*Botany

ISBN 978-0-00-220212-1. Possingham, J. V.; Rose, R. J. (May 18, 1976). "Chloroplast Replication and Chloroplast DNA Synthesis ... have unique organelles known as chloroplasts. Chloroplasts are thought to be descended from cyanobacteria that formed ... Chloroplasts and cyanobacteria contain the blue-green pigment chlorophyll a. Chlorophyll a (as well as its plant and green ... Chloroplasts are inherited through the male parent in gymnosperms but often through the female parent in flowering plants. A ...

*Blidingia minima

Stellate chloroplasts also exist. The tubes rise in groups from the center. It thalli grow as clusters which carry cylindrical ...

*Red algae

Chloroplasts evolved following an endosymbiotic event between an ancestral, photosynthetic cyanobacterium and an early ... According to this theory, over time these endosymbiont red algae have evolved to become chloroplasts. This part of ... The red algae form a distinct group characterized by having eukaryotic cells without flagella and centrioles, chloroplasts that ... within their chloroplasts. Some marine species are found on sandy shores, while most others can be found attached to rocky ...

*R. John Ellis

Blair, G. E.; Ellis, R. J. (1973). "Protein synthesis in chloroplasts. I. Light-driven synthesis of the large subunit of ... Barraclough, R.; Ellis, R. J. (1980). "Protein synthesis in chloroplasts IX. Assembly of newly-synthesised large subunits into ... 1973: First identification of a product of protein synthesis by chloroplast ribosomes. 1978: First demonstration of in vitro ... 1983: Elected Fellow of the Royal Society of London for contributions to chloroplast biogenesis. 1983: Five-year Senior ...

*Steve A. Kay

Atkins, K.A. & Dodd, A.N. (2014). "Circadian Regulation of Chloroplasts". Current Opinion in Plant Biology. 21: 43-50. doi: ...

*Ceratoperidiniaeceae

Member species possess chloroplasts. Reñé, Albert; de Salas, Miguel; Camp, Jordi; Balagué, Vanessa; Garcés, Esther (September ...

*Loxopterygium

"Loxopterygium huasango isolate 68 maturase K (matK) gene, partial cds; chloroplast." National Center for Biotechnology ...

*Differential centrifugation

... chloroplasts, lysosomes, and peroxisomes; Microsomes (vesicles of disrupted endoplasmic reticulum); and Ribosomes and cytosol. ...

*Robin Hill (biochemist)

Walker, D. A.; Hill, R (1967). "The relation of oxygen evolution to carbon assimilation with isolated chloroplasts". Biochimica ... Hill, R.; Bendall, F. (1960). "Function of the Two Cytochrome Components in Chloroplasts: A Working Hypothesis". Nature. 186 ( ... Hill, R. (1939). "Oxygen Produced by Isolated Chloroplasts". Proceedings of the Royal Society B: Biological Sciences. 127 (847 ... subscription required) Bendall, D.S. (1971). "[33] Cytochrome components in chloroplasts of the higher plants". Methods in ...

*Hill reaction

... is reduced in chloroplasts to NADPH. Overall within a chloroplast, the following equilibrium reaction takes place. A reduction ... The ferrocyanide is reduced (just as NADP is when the chloroplast is in vivo) while water (H2O) is oxidized into oxygen (O2) ... He demonstrated that isolated chloroplasts would make oxygen (O2) but not fix carbon dioxide (CO2). This is evidence that the ... The reaction in which oxygen is released takes place within the chloroplast of plants and the Hill reaction demonstrated that ...

*Light-dependent reactions

PS II, PS I, and cytochromeb 6 are found in chloroplasts. All plants and all photosynthetic algae contain chloroplasts, which ... They do not contain chloroplasts. Rather, they bear a striking resemblance to chloroplasts themselves. This suggests that ... The photosynthesis process in chloroplasts begins when an electron of P680 of PSII attains a higher-energy level. This energy ... PS II is a transmembrane structure found in all chloroplasts. It splits water into electrons, protons and molecular oxygen. The ...

*Protein disulfide-isomerase

In the chloroplasts of the unicellular algae Chlamydomonas reinhardtii the protein disulfide-isomerase RB60 serves as a redox ... Wittenberg G, Danon A (2008). "Disulfide bond formation in chloroplasts". Plant Science. 175 (4): 459-466. doi:10.1016/j. ... disulfide-isomerase has also been suggested to play a role in the formation of regulatory disulfide bonds in chloroplasts. ...

*Prokaryote

This is one of many pieces of evidence that mitochondria and chloroplasts are themselves descended from free-living bacteria. ... However, two organelles found in many eukaryotic cells, mitochondria and chloroplasts, contain ribosomes similar in size and ... Prokaryotes lack mitochondria and chloroplasts. Instead, processes such as oxidative phosphorylation and photosynthesis take ...

*Pheophorbide a oxygenase

"Chlorophyll breakdown in senescent chloroplasts. Cleavage of pheophorbide a in two enzymic steps". Plant Physiol. 115 (2): 669- ...

*Gerontoplast

doi:10.1007/978-94-017-0247-8_4. "Transformation of Chloroplast to Gerontoplast" (PDF). Chloroplast Biogenesis: 155-242. doi: ... Biswal, Udaya; Mukesh, Raval (2003). "Transformation of Chloroplast to Gerontoplast". Chloroplast Biogenesis. Springer, ... Chloroplasts responsible for gas exchange in stomata are the last organelles to degrade during senescence. The formation of ... A gerontoplast is a plastid that develops from a chloroplast during the senescing of plant foliage. Gerontoplast development is ...

*Phototropin

... s may also be important for the opening of stomata[citation needed] and the movement of chloroplasts. Phototropins ... DeBlasio SL, Luesse DL, Hangarter RP (September 2005). "A plant-specific protein essential for blue-light-induced chloroplast ... "Chloroplast movement". Annu Rev Plant Biol. 54: 455-68. doi:10.1146/annurev.arplant.54.031902.135023. PMID 14502999. ... Phototropins have been shown to impact the movement of chloroplast inside the cell. In addition phototropins mediate the first ...

*Photosynthetic pigment

A photosynthetic pigment (accessory pigment; chloroplast pigment; antenna pigment) is a pigment that is present in chloroplasts ... In addition, most cyanobacteria use phycobiliproteins, water-soluble pigments which occur in the cytoplasm of the chloroplast, ... Some cyanobacteria, the prochlorophytes, use chlorophyll b instead of phycobilin.) It is thought that the chloroplasts in ...

*Chaetoceros diadema

Very characteristic, diadem - like spores (see species image). One chloroplast. Base of setae is short. Chaetoceros constrictus ...
Based on our phylogeny and character state reconstructions, there was one probable origin of short-term chloroplast retention in the last common ancestor of the Plakobranchoidea, and four independent origins of long-term retention. No species in the Oxynoacea and Limapontioidea were able to maintain photosynthetic activity, based on PAM measurements. Functional chloroplast retention was not detected in five oxynoacean species representing the basal shelled sacoglossans (Table 3). In species with no functional retention, chloroplasts are phagocytosed by digestive glandular cells and rapidly disintegrate [62, 63]. Clark and Busacca [64] concluded that Oxynoe retains chloroplasts because they were able to isolate chlorophyll from slugs, but they did not detect net fixation of CO2. We measured high ground fluorescence in oxynoaceans but very low yield values, indicating free chlorophyll but no functional chloroplasts.. Similarly, all limapontioidean species except Costasiella cf. kuroshimae had ...
The TIC and TOC complexes are translocons located in the chloroplast of a eukaryotic cell, that is, protein complexes that facilitate the transfer of proteins in and out through the chloroplasts membrane. The TIC complex (translocon on the inner chloroplast membrane) is located in the inner envelope of the chloroplast. The TOC complex (translocon on the outer chloroplast membrane) is located in the outer envelope of the chloroplast. It transports proteins that are synthesized in the cytoplasm across the chloroplasts membrane. This protein complex is functionally similar to the TOM/TIM Complex located on the outer and inner membranes of the mitochondria, in the sense that it too transports proteins across multiple membranes and into the lumen of an organelle. Both complexes (TOC/TIC) are GTPases, that is, they must both hydrolyze GTP in order to power the translocation. The chloroplast also harnesses the power of an electrochemical gradient using protons. The gradient is only used to power ...
Successful import of hundreds of nucleus-encoded proteins is essential for chloroplast biogenesis. The import of cytosolic precursor proteins relies on the Toc- (translocon at the outer chloroplast membrane) and Tic- (translocon at the inner chloroplast membrane) complexes. In |i|Arabidopsis thaliana|/i|, precursor recognition is mainly mediated by outer membrane receptors belonging to two gene families: Toc34/33 and Toc159/132/120/90. The role in import and precursor selectivity of these receptors has been intensively studied, but the function of Toc90 still remains unclear. Here, we report the ability of Toc90 to support the import of Toc159 client proteins. We show that the overexpression of Toc90 partially complements the albino knockout of Toc159 and restores photoautotrophic growth. Several lines of evidence including proteome profiling demonstrate the import and accumulation of proteins essential for chloroplast biogenesis and functionality. Infanger, Sibylle; Bischof, Sylvain;
Figure 14 Phase contrast fluorescence microscopy of Cry2A transgenic plants with transit peptide. A = DAPIblue fluorescence. B = FITC green fluorescence. C = Chloroplast auto-fluorescence red. D = Merged image of A, B and C. Yellow color is produced where green and red fluorescence occurred at the same place i.e. Cry2A inside chloroplasts.. Discussion. Chloroplast targeted expression of the Bt gene holds great potential for incorporating vital agronomic traits into plants. High Bt gene levels in chloroplasts permits plants to generate large quantities of crystal proteins. In the present study, two insecticidal genes, Cry1Ac and Cry2A, along with a chloroplast transit peptide were cloned in a PBI-121 vector and transformed into cotton variety MNH-786. Cry1Ac and Cry2A were selected because of their unique qualities, i.e., high expression levels and lack of competition for receptors among them.. The present study highlights the importance of cloning genes with transit peptides to demonstrate ...
The import of nucleus-encoded proteins into chloroplasts is mediated by translocon complexes in the envelope membranes. A component of the translocon in the outer envelope membrane, Toc34, is encoded in Arabidopsis by two homologous genes, atTOC33 and atTOC34. Whereas atTOC34 displays relatively uniform expression throughout development, atTOC33 is strongly upregulated in rapidly growing, photosynthetic tissues. To understand the reason for the existence of these two related genes, we characterized the atTOC33 knockout mutant ppi1. Immunoblotting and proteomics revealed that components of the photosynthetic apparatus are deficient in ppi1 chloroplasts and that nonphotosynthetic chloroplast proteins are unchanged or enriched slightly. Furthermore, DNA array analysis of 3292 transcripts revealed that photosynthetic genes are moderately, but specifically, downregulated in ppi1. Proteome differences in ppi1 could be correlated with protein import rates: ppi1 chloroplasts imported the ...
Chloroplasts are organelles found in plant cells and eukaryotic algae which conduct photosynthesis. Chloroplasts are similar to mitochondria but are found only in plants. Both organelles are surrounded by a double membrane with an intermembrane space; both have their own DNA and are involved in energy metabolism; and both have reticulations, or many foldings, filling their inner spaces. Chloroplasts convert light energy from the sun into ATP through a process called photosynthesis. Chloroplasts are one of the forms a plastid may take, and are generally considered to have originated as endosymbiotic cyanobacteria. In green plants chloroplasts are surrounded by two lipid bilayer membranes, now thought to correspond to the outer and inner membranes of the ancestral cyanobacterium. The genome is considerably reduced compared to that of free-living cyanobacteria, but the parts that are still present show clear similarities. It is interesting to note that in some algae, chloroplasts seem to have ...
Chloroplasts change their position in a cell in response to environmental light conditions (Wada et al., 1993, 2003). Low-fluence rate light induces movement of chloroplasts toward the irradiated area, resulting in chloroplast accumulation at the front face of the cell (accumulation response). Conversely, under high-fluence rate light, chloroplasts move to the anticlinal wall of the cell to avoid photodamage (avoidance response; Kasahara et al., 2002). Chloroplast photorelocation movement is found in several photosynthetic plant species, including yellow and green algae, mosses, ferns, and flowering plants. In most plant species, chloroplast movement is induced by irradiation with blue light, although it is also induced by red light in some cryptogam plants (Wada et al., 1993, 2003). The flowering plant Arabidopsis (Arabidopsis thaliana) has two types of blue-light photoreceptor, cryptochromes (cry1 and cry2) and phototropins (phot1 and phot2). Cryptochrome is a flavoprotein similar to the ...
Chloroplasts originated from an endosymbiotic event in which a free-living cyanobacterium was engulfed by an ancestral eukaryotic host. During evolution the majority of the chloroplast genetic information was transferred to the host cell nucleus. As a consequence, proteins formerly encoded by the chloroplast genome are now translated in the cytosol and must be subsequently imported into the chloroplast. This process involves three steps: (i) cytosolic sorting procedures, (ii) binding to the designated receptor-equipped target organelle and (iii) the consecutive translocation process. During import, proteins have to overcome the two barriers of the chloroplast envelope, namely the outer envelope membrane (OEM) and the inner envelope membrane (IEM). In the majority of cases, this is facilitated by two distinct multiprotein complexes, located in the OEM and IEM, respectively, designated TOC and TIC. Plants are constantly exposed to fluctuating environmental conditions such as temperature and light ...
Christoph Benning MSU Foundation Professor; Director, Plant Research Laboratory, Michigan State University Research: Biosynthesis of lipids in photosynthetic membranes, lipid trafficking phenomena involving chloroplasts, engineering of crops and algae for biodiesel production. Lipid Assembly, Remodeling, and Transport to Build and Protect the Photosynthetic Membrane Photosynthesis sustains most life forms on earth providing food, feed, fuels, organic chemicals, and the oxygen in the atmosphere. In plants and algae, the photosynthetic membrane inside chloroplasts mediates the conversion of light into chemical energy. Specific polar lipids consisting of fatty acyl groups attached to glycerol with a polar head group are key components of the photosynthetic membrane. Fatty acid biosynthesis occurs in the chloroplasts, and polar lipids destined for the photosynthetic membrane are assembled at both chloroplast envelope membranes and the endoplasmic reticulum. Lipid precursors have to be shuttled between
Plastocyanin is a nuclear-encoded chloroplast thylakoid lumen protein that is synthesized in the cytoplasm with a large N-terminal extension (66 amino acids). Transport of plastocyanin involves two steps: import across the chloroplast envelope into the stroma, followed by transfer across the thylakoid membrane into the lumen. During transport the N-terminal extension is removed in two parts by two different processing proteases. In this study we examined the functions of the two cleaved parts, C1 and C2, in the transport pathway of plastocyanin. The results show that C1 mediates import into the chloroplast. C1 is sufficient to direct chloroplast import of mutant proteins that lack C2. It is also sufficient to direct import of a nonplastid protein and can be replaced functionally by the transit peptide of an imported stromal protein. C2 is a prerequisite for intraorganellar routing but is not required for chloroplast import. Deletions in C2 result in accumulation of intermediates in the stroma or ...
How do plant cells get rid of chloroplasts that are not working as they should? Woodson et al. describe a chloroplast quality-control pathway that allows for the selective elimination of individual chloroplasts. Damage by reactive oxygen species during photosynthesis is recognized by a ubiquitin ligase, which marks out damaged chloroplasts for degradation. The findings reveal how cells balance inherently stressful energy production with organelle turnover.. J. D. Woodson, M. S. Joens, A. B. Sinson, J. Gilkerson, P. A. Salomé, D. Weigel, J. A. Fitzpatrick, J. Chory, Ubiquitin facilitates a quality-control pathway that removes damaged chloroplasts. Science 350, 450-454 (2015). [Abstract] [Full Text] ...
During the course of NH4+ (or NO2-)-plus-alpha-oxoglutarate-dependent O2 evolution in spinach (Spinacia oleracea) chloroplasts, glutamate was continuously excreted out of the chloroplasts. Under these conditions, for each molecule of NO2- or NH4+ which disappeared, one molecule of glutamate accumulated in the medium and the concentration of glutamate in the stroma space was maintained constant. SO4(2-) (or SO3(2-) behave as inhibitors of NH4+ incorporation into glutamate by intact chloroplasts. This considerable inhibition of glutamate synthesis by SO4(2-) was correlated with a rapid decline in the stromal Pi concentration. The reloading of stromal Pi with either external Pi or PPi4- relieved SO4(2-)-induced inhibition of glutamate synthesis by intact chloroplasts. It was concluded that SO4(2-) induced a rapid efflux of stromal Pi out of the chloroplast, leading to a limitation of ATP synthesis and therefore to an arrest of ATP-dependent glutamine synthetase functioning. ...
The chloroplast is the site of photosynthesis that enabled and sustains aerobic life on Earth. Chloroplasts are relatively large organelles with a diameter of ~5 μm and width of ~2.5 μm, and so can be readily analysed by electron microscopy. Each chloroplast is enclosed by two envelope membranes, which encompass an aqueous matrix, the stroma and the thylakoids. Components of stroma include starch granules and plastoglobuli, which can be observed by electron microscopy. And the thylakoids consist of stromal thylakoid, granal thylakoid and as well as granum (a stack of thylakoids). These structure components are quite sensitive to developmental changes and environmental variations, such as drought, salinity, cold, high temperature and others. Transmission electron microscopy (TEM) is a powerful technique for monitoring the effects of various changing parameters or treatments on the development and differentiation of these important organelles. Here we describe a reliable method for the analysis of
We present a neural network based method (ChloroP) for identifying chloroplast transit peptides and their cleavage sites. Using cross-validation, 88% of the sequences in our homology reduced training set were correctly classified as transit peptides or nontransit peptides. This performance level is well above that of the publicly available chloroplast localization predictor PSORT. Cleavage sites are predicted using a scoring matrix derived by an automatic motif-finding algorithm. Approximately 60% of the known cleavage sites in our sequence collection were predicted to within +/-2 residues from the cleavage sites given in SWISS-PROT. An analysis of 715 Arabidopsis thaliana sequences from SWISS-PROT suggests that the ChloroP method should be useful for the identification of putative transit peptides in genome-wide sequence data. The ChloroP predictor is available as a web-server at http://www.cbs.dtu.dk/services/ChloroP/.. ...
Post-translational protein methylation was investigated in Pisum sativum chloroplasts. Intact pea chloroplasts were incubated with ({sup 3}H-methyl)-S-adenosylmethionine under various conditions. The chloroplasts were then separated into stromal and thylakoid fractions and analyzed for radioactivity transferred to protein. Light enhanced the magnitude of labeling in both fractions. One thylakoid polypeptide with an apparent molecular mass of 43 kDa was labeled only in the light. Several other thylakoid and stromal proteins were labeled in both light and dark-labeling conditions. Both base-labile methylation, carboxy-methylesters and base-stable groups, N-methylations were found. Further characterization of the methyl-transfer reactions will be presented. ...
Plant cells contain an internal clock (the circadian clock), which is able to regulate cellular processes so that they occur at the optimal time of day, causing a big increase in plant productivity. As chloroplasts are the site of photosynthesis, their function is highly dependent on the daily changes in light environment.. It is thought that chloroplasts were originally free-living organisms that were incorporated into the cells of plants very early in plant evolutionary history. A result of this is that chloroplasts have retained some of the cellular machinery required to produce proteins from their own chloroplast DNA. An essential part of this machinery are sigma factors, and in present-day plants, they are encoded for by the cells nuclear DNA.. The researchers were able to show that the production of sigma factors is controlled by the plants clock. This enables the nuclear DNA to regulate the activity of chloroplast genes, and ensure that the production of proteins essential for ...
A plastid is an organelle that is commonly found in photosynthetic plants. Plastids are of different types depending on the presence of the pigment and metabolic functions. They may be chloroplasts, chromoplasts, and leucoplasts. A chloroplast is a plastid that contains high amounts of green pigment, chlorophyll. The chlorophyll pigments may be chlorophyll a, chlorophyll b, chlorophyll c, chlorophyll d, and chrlorophyll f. Chlorophyll a is present in all chloroplasts. Other pigments that may be present (particularly in algal cells) are carotenoids and phycobilins. The chloroplast has at least three membrane systems: outer membrane, inner membrane, and thylakoid system. The thylakoids are disk-shaped structures that function as the site of photosynthesis. It is because embedded in the thylakoid membrane is the antenna complex consisting of proteins, and light-absorbing pigments, including chlorophyll (the green pigment) and carotenoids. The chlorophyll is capable of absorbing light energy for use ...
Word Scramble - English word CHLOROPLASTS: words that start with chloroplasts, words that end with chloroplasts, anagrams of chloroplasts, how to spell chloroplasts!, Words with Friends, Scrabble
Numerous studies show ramifications of abscisic acid solution (ABA) about nuclear genes encoding chloroplast-localized proteins. It repressed transcription from the chloroplast phage-type T0070907 and bacteria-type RNA polymerases and reduced transcript degrees of most looked into chloroplast genes significantly. ABA didnt repress the transcription of and some other genes as well as increased mRNA amounts under certain circumstances. The ABA results on chloroplast transcription had been even more pronounced in basal vs. apical leaf sections and improved by light. Simultaneous software of cytokinin (22 μM 6-benzyladenine) reduced the ABA results on chloroplast gene manifestation. These data show that ABA impacts the manifestation of chloroplast genes differentially and factors to a job of ABA in the rules and coordination of the actions of nuclear and chloroplast genes coding for protein with features in photosynthesis. (L.) nucleus-encoded plastid RNA polymerase (NEP) plastid-encoded plastid ...
In this study, we produced selective images of photosystems in plant chloroplasts in situ. We used a spectroimaging microscope, equipped with a near-infrared (NIR) laser that provided light at wavelengths mainly between 800 and 830 nm, to analyze chlorophyll autofluorescence spectra and images from chloroplasts in leaves of Zea mays at room temperature. Femtosecond laser excitation of chloroplasts in mesophyll cells revealed a spectral shape that was attributable to PSII and its antenna in the centers of grana spots. We found that a continuous wave emitted by the NIR laser at a wavelength as long as 820 nm induced chlorophyll autofluorescence with a high contribution from PSI through a one-photon absorption mechanism. A spectral shape attributable to PSI and its antenna was thus obtained using continuous wave laser excitation of chloroplasts in bundle sheath cells. These highly pure spectra of photosystems were utilized for spectral decomposition at every intrachloroplast space to show ...
Chloroplasts are organelles that take light energy and convert it into chemical energy. A chloroplast has a double membrane, the inner and outer membranes. The inner thylakoid membrane traps the light energy. Inside the inner membrane are stacks of grana, and surrounding the grana is a fluid known as stroma. Chloroplasts, which are contained in chlorophyll, contain the green pigment chlorophyll, which traps light energy and make leaves and stems green. The chemical energy that is captured by the chloroplasts is stored in sugar molecules until they are broke down. ...
Berkeley - As biologists try to tease out the finer details of the green plant family tree, one key may lie in the cellular organelle - the chloroplast - that makes green plants green. As the photosynthetic factory of the plant cell, the chloroplast contains its own complement of genes distinct from the comparably sized mitochondrial genome in the energy center of the cell or the much larger genome in the cell nucleus. "The chloroplast genome can be more informative in some ways than the complete nuclear genome, and easier to analyze than plant mitochondrial DNA," said Brent Mishler, professor of integrative biology at the University of California, Berkeley, and director of the Jepson and University Herbaria. Mishler is one of nine principal investigators on a new project, supported by $3 million over five years from the National Science Foundation, to isolate and sequence chloroplast and mitochondrial genomes from 50 to 100 representative plants, drawing on the expertise of the U.S. Department ...
Introduction. How ATP is produced in both the chloroplast and mitochondria Introduction: Living organisms use it as a free-energy donor to supply free energy for three major purposes: muscular contraction and other cellular movements, the active transport of molecules and ions, and the synthesis of proteins. ATP is not a long-term storage form of energy - is an immediate donor of energy. Most ATP is consumed within a minute ofbeing produced. The turnover of ATP is very high . ATP Generation in Mitochondria and Chloroplasts: ATP generation is driven by the electrochemical gradient of protons (the proton motive force) that exists in both mitochondria and chloroplasts. However, the mechanisms in each organelle are different when compared in detail, as will be considered later. In both chloroplasts and mitochondria the driving force behind ATP synthesis is the proton motive force that exists between two cellular compartments. This force is produced by the electrochemical gradient for H+ across the ...
(figure) Figure 1.7 A mature and functional chloroplast in an immature leaf of bean (Phaseolus vulgaris) with an extensive network of photosynthetic membranes (thylakoids), parts of which are appressed into moderate granal stacks, and suspended in a gel-like matrix (stroma).The chloroplast contains a pair of starch grains (S) encapsulated in a doub
Plant cotyledons are a tissue that is particularly active in plastid gene expression in order to develop functional chloroplasts from pro-plastids, the plastid precursor stage in plant embryos. Cotyledons, therefore, represent a material being ideal for the study of composition, function and regulation of protein complexes involved in plastid gene expression. Here, we present a pilot study that uses heparin-Sepharose and phospho-cellulose chromatography in combination with isoelectric focussing and denaturing SDS gel electrophoresis (two-dimensional gel electrophoresis) for investigating the nucleotide binding proteome of mustard chloroplasts purified from cotyledons. We describe the technical requirements for a highly resolved biochemical purification of several hundreds of protein spots obtained from such samples. Subsequent mass spectrometry of peptides isolated out of cut spots that had been treated with trypsin identified 58 different proteins within 180 distinct spots. Our analyses indicate a high
Glyceraldehyde 3-phosphate dehydrogenases (EC 1.2.1.12 and 1.2.1.13) have been purified from the seed, root, etiolated, and green shoot of peas (Pisum sativum). These enzymes are tetramers of 140,000 daltons, with subunits of 35,000 daltons. The enzymes differ in isoelectric point. The seed enzyme has a pI of 5.1, and the root enzyme has a pI of 4.5. The cytoplasmic enzyme from etiolated shoots is slightly acidic with a pI of 5.7 to 6.1 and is found in two separable forms. The chloroplast enzyme (from green shoots) is most basic with a pI of 8.0.. In immunodiffusion experiments, the seed, root, and cytoplasmic enzymes of the etiolated shoot share antigenic homology, while the chloroplast enzyme does not cross react antigenically with the extra-chloroplast enzymes. The antiserum to the pea chloroplast enzyme did, however, cross react with glyceraldehyde 3-phosphate dehydrogenase purified from the spinach chloroplast. Therefore, the chloroplast enzyme is significantly different from the ...
A two-membrane system, or envelope, surrounds plastids. Because of the integration of chloroplast metabolism within the plant cell, the envelope is the site of many specific transport activities. However, only a few proteins involved in the processes of transport across the chloroplast envelope have been identified already at the molecular level. To discover new envelope transporters, we developed a subcellular proteomic approach, which is aimed to identify the most hydrophobic envelope proteins. This strategy combined the use of highly purified and characterized membrane fractions, extraction of the hydrophobic proteins with organic solvents, SDS/PAGE separation, and tandem mass spectrometry analysis. To process the large amount of MS/MS data, a blast-based program was developed for searching in protein, expressed sequence tag, and genomic plant databases. Among the 54 identified proteins, 27 were new envelope proteins, with most of them bearing multiple α-helical transmembrane regions and being very
Although some members of the major facilitator superfamily are known to play a role in transport into organelles, until now, transporters of the PiT and PHS families have not been found in organellar membranes. The initial clue to the location of PHT2;1 came from its long N-terminal extension, which is a feature unique to the plant members of the PiT family. In other transport families, extended N-terminal regions have been associated with regulation (Harper et al., 1998; Pittman and Hirschi, 2001), and Daram et al. (1999) proposed this function for PHT2;1 as well. However, computer predictions indicated that the N-terminal region probably was a transit peptide, and localization of a PHT2;1-GFP fusion protein confirmed that PHT2;1 resides in the chloroplast. The ChloroP 1.1 program predicted correctly a chloroplast localization for PHT2;1 and suggested a cleavage site between amino acids 71 and 72, which results in a transit peptide similar in length to those of the TPTs (Fischer et al., ...
Heterologous regulatory elements and flanking sequences have been used in chloroplast transformation of several crop species, but their roles and mechanisms have not yet been investigated. Nucleotide sequence identity in the photosystem II protein D1 (psbA) upstream region is 59% across all taxa; si …
In higher plants, chloroplasts are the site for the photosynthetic reactions, converting solar energy to chemical energy. Within the chloroplast the thylakoid membrane network encloses the soluble lumen compartment. Until recently the knowledge of the lumen composition and function was limited, but a more profound understanding of the thylakoid lumen content is gradually emerging. The discovery that the thylakoid lumen contains numerous enzymes, besides the already known proteins directly involved or associated with the photosynthetic reactions, have changed the view on this compartment.. The first part of the thesis the lumen proteome maps of Arabidopsis and spinach were resolved. These two proteome maps showed good correlation and the same protein groups were represented in the two proteomes. Thirty eight proteins were identified and in combination with an in silico prediction for the proteome it was estimated that at least 80 different proteins are lumen located.. The second part was to ...
The PGR5 (PROTON GRADIENT REGULATION 5) gene that is required for PSI cyclic electron transport in Arabidopsis was knocked down in rice (Oryza sativa). In three PGR5 knockdown (KD) lines, the PGR5 protein level was reduced to 5-8% of that in the wild type, resulting in a 50% reduction in PGRL1 (PGR5-LIKE PHOTOSYNTHETIC PHENOTYPE 1) protein levels. In ruptured chloroplasts, ferredoxin-dependent plastoquinone reduction activity was partially impaired; the phenotype was mimicked by addition of antimycin A to wild-type chloroplasts. As occurred in the Arabidopsis pgr5 mutant, non-photochemical quenching of Chl fluorescence (NPQ) induction was impaired in the leaves, but the electron transport rate (ETR) was only mildly affected at high light intensity. The P700+ level was reduced even at low light intensity, suggesting that the PGR5 function was severely disturbed as in the Arabidopsis pgr5 mutant and that the other alternative routes of electrons could not compensate the stromal redox balance. The ...
Harsman, A.; Schock, A.; Hemmis, B.; Wahl, V.; Jeshen, I.; Bartsch, P.; Schlereth, A.; Pertl-Obermeyer, H.; Goetze, T.A.; Soll, J. et al.; Philippar, K.; Wagner, R.: OEP40, a regulated glucose-permeable β-barrel solute channel in the chloroplast outer envelope membrane. Journal of Biological Chemistry 291 (34), S. 17848 - 17860 (2016 ...
Two cytoplasmic organelles responsible for the production of energy are the mitochondria (present in nearly all eukaryotic cells) and chloroplasts (present only in photosynthetic organisms). Both contain small, circular DNA molecules that constitute the nonnuclear portion of a eukaryotic genome. These organelles are descended from formerly free-living bacteria that took up residence in the first eukaryotes.. The human mitochondrial genome contains 16,569 base pairs specifying 13 protein products and 24 RNA products. In both lower eukaryotes and especially plants, larger mitochondrial genomes are present. In extreme cases, mitochondrial genomes may be several hundred thousand or millions of base pairs. Chloroplast genomes contain between 100 and 200 kilobases. It is thought that each was once larger, but over time their genes have been moved to the nucleus.. ...
If you have a question about this talk, please contact jb511.. Metal cofactor assembly in chloroplasts. Dr Marinus Pilon, Colorado State University. Genomic analyses have indicated that about a third of all proteins require a metal cofactor for activity. Cells must regulate and prioritize the delivery of metal ion cofactors by membrane transport processes to targets in various organelles. The growth environment often limits the availability of metal cofactors. Under limitation cells should therefore prioritize delivery to specific targets and coordinate delivery with apo-protein expression as well as varying metabolic demand. Targets for Cu delivery in plant chloroplasts are plastocyanin in the thylakoids and Cu/Zn-superoxide dismutase (Cu/ZnSOD) in the stroma. PAA1 and PAA2 encode Cu-transporting P-type ATPases. Characterization of paa1 and paa2 mutants showed that the two transporters have distinct functions; whereas both transporters are required for Cu delivery to plastocyanin and efficient ...
In order to measure interaction between the rbcL and atpB promoters, deletion mutants were constructed that increased or decreased the intergenic region between the promoters. Fewer RNA transcripts were produced from the mutants that altered the spacing, compared to the wild-type constructions. Therefore, the optimal spacing between the two promoters is the 152 bp region present in the wild-type DNA. Additional mutants were constructed which either removed the rbcL promoter or removed regions of the rbcL gene at the 3$\sp\prime$ end of the promoter. Transcription from the atpB promoter increased substantially when the rbcL promoter was removed. Deletions located 11 bp 5$\sp\prime$ to the -35 region of the atpB promoter did not transcribe this promoter with fidelity; instead, multiple transcripts were produced. These data indicated that the spinach atpB promoter and rbcL promoters interact transcriptionally and that sequences with the intergenic region are necessary for accurate transcription ...
Method. A specific set of actions were used to prepare the chloroplasts for the samples to be used in the experiment. Spinach leaves were placed under a lamp in order to activate the chloroplasts in the leaves while the osmolarity fluid was prepared. Point five sucrose osmolarity fluid was used for the experiment to provide an environment for the chloroplasts that was neither too hypertonic nor too hypotonic. The osmolarity fluid was poured up to the top of the blades of the blender. The stems were removed from the spinach leaves because they contain few chloroplasts. The top of the blender body was placed on the body and the blender was activated in ten second bursts to keep the contents from heating, because heating would de-nature the proteins in the chloroplasts and cause them to no longer function normally. The purpose of blending the spinach leaves was to free the chloroplasts from the cells they were contained in. Two layers of cheese cloth were placed on top of a beaker. The contents of ...
The assembly of the photosynthetic apparatus requires the translocation of numerous proteins from the cytosol, initially into the stroma and thereafter into or across the thylakoid membrane. Recent studies have shown that proteins are transported into this membrane by a variety of mechanisms, some of which are derived from a cyanobacterial-type ancestor, whereas others have evolved in response to the more complex transport pathway used by cytosolically synthesized chloroplast proteins. It is now apparent that some of the targeting pathways are used exclusively by hydrophobic thylakoid membrane proteins; here we review recent progress in our understanding of the biogenesis of this important class of protein.. ...
The chloroplast genome of higher plants is relatively small and simple. This genome contains about 120 genes which code for chloroplast proteins. The organelles genome also contains ribosomal RNA genes which code for the RNA components of the chloroplast ribosome. In this program, students identify the ribosomal RNA genes in the chloroplast genome of spinach. Students first isolate chloroplasts from fresh spinach and then prepare DNA from the isolated organelle. The DNA is digested with EcoR1, electrophoresed, and the separated fragments transferred to a nylon membrane. The DNA fragments containing the ribosomal genes are then detected by hybridization using a biotin-labeled probe made from a plasmid that contains the ribosomal gene sequences. Fresh spinach, microscopes, ethyl alcohol, a water bath incubator that will maintain a temperature of 60-65°C, and a centrifuge that can be operated at a force of at least 3000 x g are needed for the program. A microcentrifuge is also desirable, but not ...
The chloroplasts are lens-shaped organelles found in leaves and other green organisms. In the green tissue, in the interior of the leaf, are mesophyll. Each mesophyll has about 30 or 40 chloroplasts. Chloroplasts are made up of saclike photosynthetic membranes. These membranes are in such an order that they form stacks called grana. Next to the grana are thylakoids which separate the grana from the stroma, the fluid out side the thylakoid. Inside the grana are the pigments involved in photosynthesis. The pigments in the chloroplast are called ...
Researchers at the RIKEN Center for Sustainable Resource Science in Japan have discovered a gene in plants that helps protect them from excessive heat. Published in the scientific journal Plant Cell, the study shows that the newly found gene prevents the destabilization of chloroplast membranes that occurs at very high temperatures.. We all know how uncomfortable it is to be stuck outside on a sweltering hot day. Now, imagine how bad it would be if you were a soybean or tomato plant without any chance of moving inside. Eventually your leaves might become bleached of color due to chloroplast membrane damage, and if you did not get any relief, you might die. Fortunately for plants, they do have a natural defense against this type of stress that involves modifying plant fats that make up chloroplast membranes. When heat causes chloroplast membranes to destabilize, polyunsaturated fatty acids are removed from the membrane lipids, which stabilizes the membranes. The team at RIKEN found the gene ...
The formation of grana in chloroplasts of higher plants is examined in terms of the subtle interplay of physicochemical forces of attraction and repulsion. The attractive forces between two adjacent membranes comprise (1) van der Waals attraction that depends on the abundance and type of atoms in each membra In honour of James Barber
Import of chloroplast Omp85 homologs in vitro. (A) Chloroplasts isolated from pea seedlings were incubated with radiolabeled proteins indicated at left in the i
... Definition Chloroplast is an organelle unique to plant cells that contains chlorophyll, which is what makes plants green and is responsible for enabling photosynthesis to occur, so that plants can convert sunlight into chemical energy. It is a type of organelle known as a plastid, characterized by
Scientists have puzzled for years in understanding how plants pass signals of stress due to lack of water or salinity from chloroplast to nucleus. They know that chloroplasts - the cellular organelles that give plants their ...
Chloroplasts convert light into chemical energy fuelling life on earth. They contain their own expression apparatus and set of genes. Transplastomic technologies allow precise targeted integration of trait genes into chloroplasts without marker genes. Industrial and therapeutic proteins expressed in chloroplasts accumulate to extraordinarily high levels providing an attractive production platform for manufacture of high-value products for industry and health, which is both sustainable and carbon-neutral. Maternal inheritance of chloroplast genes prevents the pollen-mediated spread of transgenes providing a natural form of gene containment for the next generation of Biotech crops. Biotechnological applications of this new and exciting area of science are underpinned by fundamental research on the genes present in chloroplasts.. ...
and H2O2 is commonly associated with photosystem I (PSI) activity, recent reports have questioned the role of PSI electron transfer to molecular oxygen as a main source of ROS in higher plants [30,31]. Imbalanced electron transfer reactions may also lead to the formation of singlet oxygen (1O2) in PSII [32,33]. However, chloroplasts are well equipped with a multitude of overlapping antioxidant systems, which maintain ROS below dangerous levels for the cells.. Even though harsh redox modifications may have deleterious effects on photosynthetic activity [34], the accumulation of redox-active intermediates and/or ROS becomes beneficial in terms of signalling effects against different types of stress, including high light and pathogens [35]. Recent work done with green algae has suggested a possible mechanism explaining this tight relationship. Expression of a nuclear-encoded reporter gene coupled to a H2O2 sensitive promoter was shown to respond not only to the levels of exogenously added H2O2 but ...
Production of a recombinant bacterial lipoprotein in higher plant chloroplasts. Regulating transgenic crops sensibly: Lessons from plant breeding, biotechnology and genomics
Rabbit polyclonal thylakoid lumen proteins antibody. Validated in WB and tested in Spinacia oleracea. Immunogen corresponding to tissue, cells or virus.
Does anyone have information concerning the possibility of Agrobacterium integrating its DNA into the genomes of plant organelles other that the nucleus (chloroplasts or mitochondria?). Thanks for any information you can give me. Brandt G. Cassidy Assistant Scientist Plant Biology The Samuel Roberts Noble Foundation e-mail BGCASSIDY at noble.org ...
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Two independent endosymbiotic events gave rise to mitochondria and chloroplasts. Despite the fact that both organelles have their own small genome the majority of organellar proteins are encoded in the nucleus, synthesized in the cytosol and imported into the organelles. The targeting information for most organellar proteins is located in an N-terminal extension called a targeting peptide. Targeting peptides are cleaved off after import by organellar processing peptidases. The cleaved targeting peptides are toxic to organellar functions and are degraded by the PreP peptidasome, the metalloendopeptidase which is the main topic of this thesis.. We have overexpressed, purified and determined the first structure of a plant mitochondrial targeting peptide, the F1β presequence from Nicotiana plumbaginifolia, by NMR in a membrane mimetic environment. The structure showed that the targeting peptide formed two helices separated by an unstructured domain. The N-terminal helix being amphipatic. The F1β ...
A song about Plants - cell walls, cuticles, organelles called chloroplasts, glucose & photosynthesis. Free mp3 download & chapter summary notes.
In nature, sessile plants have to adapt to their environment and to the never ending changes they are exposed to. They do so mainly by proteomic and metabolomic changes. In all cells, there are complex networks of auxiliary proteins that are responsible for quality control of all the cells proteins. The auxiliary proteins are divided into chaperones and proteases, and these are further separated into different groups. Chaperones help other proteins in terms of stability and folding. In order for a protein to achieve its function, the three-dimensional structure has to be precise. A protease is a helper protein that is able to break peptide bonds in a process termed proteolysis. Chaperones and proteases can work independently, but sometimes the chaperone unfolds the substrate of the protease to ensure full degradation of the protein. In some cases, the chaperone and the protease functions are combined in one protein.. All proteins studied within this thesis are localized in the chloroplast, the ...
article{e3cc7d70-4f54-43a9-b37b-2e5c124331fa, abstract = {Mitochondria and chloroplasts are energy-transducing organelles of the cytoplasm of eukaryotic cells. They originated as bacterial symbionts whose host cells acquired respiration from the precursor of the mitochondrion, and oxygenic photosynthesis from the precursor of the chloroplast. The host cells also acquired genetic information from their symbionts, eventually incorporating much of it into their own genomes. Genes of the eukaryotic cell nucleus now encode most mitochondrial and chloroplast proteins. Genes are copied and moved between cellular compartments with relative ease, and there is no obvious obstacle to successful import of any protein precursor from the cytosol. So why are any genes at all retained in cytoplasmic organelles? One proposal is that these small but functional genomes provide a location for genes that is close to, and in the same compartment as, their gene products. This co-location facilitates rapid and direct ...
Mitochondria are known for generating energy for the cell in the form of ATP (adenosine triphosphate) by using nutrients and oxygen. The chloroplast is present in green plants and few algae, they are known as the place, where the process of photosynthesis occurs.
The most important characteristic of plants is their ability to photosynthesize, in effect, make their own food by converting light energy into chemical energy. This process is carried out in specialized organelles called chloroplasts.
Plastoglobules (PG) are lipid droplets existing in most types of plastids. Plastoglobulins (PGL) also known as fibrillins (FBN) are evolutionary conserved proteins present at the surface of PG, but to various extents also at the thylakoid membrane. PGLs are thought to have a structural function in PG, and it is known that almost the complete protein is required for PGLs to assemble on PG. Here, we report on the expression of the Arabidopsis plastoglobulin of 35kD (PGL35 or FBN1a) expressed as a mature protein fused to HIVp24 in transplastomic tobacco. A PGL35-HIVp24 fusion targeted in part to plastoglobules but a larger proportion was recovered in the thylakoid fraction. These findings suggest that PGL35-HIVp24 folds correctly after its synthesis inside the chloroplast and is then assembled not only on plastoglobules but also on thylakoid membranes. The fusion protein accumulated up to a 1% of the total protein and could be purified by biotin affinity chromatography of a total membrane extract.
Our group had to perform the experiment twice because of inaccurate data. The first time we ran the experiment, the percent transmittance jumped well past 100% for several cuvettes at the 0 minute mark, which is clearly inaccurate. After having the chloroplast added to the rest of the solution for less than a minute, there shouldnt be that strong of the ratio of intensity of the light that has passed through the sample to the intensity of the light when it entered the sample. This led us to believe that our data was not correct. We believe that the solutions were using up the chloroplast too fast, causing the unreliable data. However, after performing the experiment a second time, we received more accurate data, especially since we deluded the chloroplast with one drop of water per one drop of chloroplast. In cuvette one there was no DPIP added. The data stayed at zero the whole time. Photosynthesis was not able to take place then because there was nothing to act as an electron acceptor, ...
The 2006 Gordon Research Conference on Mitochondria and Chloroplasts will be held in Oxford, United Kingdom. Apply today to reserve your spot.
I didnt know the answer to this one, so I asked a plant physiologist friend. She said that sucrose is used as an osmotic stabilizer so that the chloroplast doesnt disintegrate. In other words, the buffer just uses sucrose as a convenient large molecule that wont cross the membrane, not for any particular biological activity. Other molecules with the same properties, such as polyethyleneglycol, can be used instead ...
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Chris Taylor at Catalogue of Organisms has an absolutely stunning review of the origin of chloroplasts in eukaryotes. Its so good I thought it was from Elio Schaechters blog Small Things Considered when it first popped up in my reader - higher praise there is not.
Ben Levin ,benjinsl at astro.ocis.temple.edu, wrote: , , , Im looking for a protocol for separating chloroplasts (centrifugation, , yes?) , I dont have the name of the book handy but its by Arnon. Do a search using his name ...
These organelles represent an excellent model system in which to study cellular protein targeting as they are easily separated from other organelles, and retain a high level of metabolic activity after isolation. In addition, they contain a level of structural complexity that requires additional sorting of proteins within the organelle. In these sorting reactions, chloroplasts utilize different protein targeting paradigms which are individually used by other organelles. Consequently, lessons learned from the study of protein targeting to and within chloroplasts can, in principle, be applied to a number of other polypeptide translocating systems ...
Observing Plant Cells In this lab students observe Elodea leaves under magnification. They will see cell walls and chloroplasts. From the movement of chloroplasts they will infer that cyclosis, or protoplasmic streaming, is occurring. They also will observe that most chloroplasts are pressed tightly against the cell wall and should infer from this that much of the cell is occupied by a vacuole. View » ...
Reverse-Genetic Studies on the In Vivo Role of the Putative Arabidopsis Orthologue of Toc12, a New Component of the Chloroplast Protein Import Apparatus. Universities UK Overseas Research Students (ORS) Award to Mr Jocelyn B dard (2002-2005) ...
I study the diversity and evolution of green algae with the use of molecular phylogenetic methods, light microscopy, and electron microscopy. I am particularly interested in unicellular algae that inhabit soils, from dry hot deserts to polar and alpine habitats to heavily polluted post-mining dumps. As part of the [http://marple.eeb.uconn.edu/gratolwww/ Green Algal Tree of Life project (GrAToL) ], the [[L._Lewis_Lab]] currently uses next-generation sequencing methods to investigate the diversity of algal chloroplast and mitochondrial genomes and the utility of organellar genes and architectures for higher taxonomy of green algae. I am also interested in the alterations of the genetic code in the mitochondria of the class Chlorophyceae, and the spread and inheritance of introns in green algal organellar genomes ...
The underlying research themes in the Stern laboratory are chloroplast biology, bioenergy and nuclear-cytoplasmic interactions. Within this framework, we study how chloroplast genes and metabolic activities are regulated by the products of nuclear genes, usually acting at the transcriptional or post-transcriptional level. Areas of emphasis include the roles of ribonucleases and RNA-binding proteins and assembly of the carbon-fixing enzyme Rubisco. We are also using molecular and genetic techniques to adjust chloroplast metabolism for the production of useful hydrocarbons.. ...
Translocase of chloroplast 33; GTPase involved in protein precursor import into chloroplasts. Seems to recognize chloroplast-destined precursor proteins and regulate their presentation to the translocation channel through GTP hydrolysis. Binds GTP, GDP, XTP, but not ATP. Probably specialized in the import of nuclear encoded photosynthetic preproteins from the cytoplasm to the chloroplast, especially during early development stages (297 aa ...
As part of the [http://marple.eeb.uconn.edu/gratolwww/ Green Algal Tree of Life project (GrAToL) ], the [[L._Lewis_Lab]] currently uses next-generation sequencing methods to investigate the diversity of algal chloroplast and mitochondrial genomes and the utility of organellar genes and architectures for higher taxonomy of green algae. I am also interested in the alterations of the genetic code in the mitochondria of the class Chlorophyceae, and the spread and inheritance of introns in green algal organellar genomes.,br ...
Photosynthetic Pigments tutorial all along with the key concepts of Pigments, Pigments in Plants, Accessory Pigments, Chloroplasts, Complexes of Pigments in Chloroplasts, Photophosphorylation-Chemiosmosis in Chloroplasts
Local stimulation induces generation and propagation of electric signals like the variation potential (VP) and action potential in plants. of light TKI-258 and dark reactions was linked to the VP. Inactivation of dark reactions reduced the rate continuous from the fast rest from the electrochromic pigment absorbance change which shown a reduction in the H+-ATP synthase activity. This reduce likely contributed towards the acidification from the chloroplast lumen which created after VP induction. TKI-258 Nevertheless VP-connected loss of the proton purpose force over the thylakoid membrane probably reflected a reduced pH in the stroma. This reduce may be another mechanism of chloroplast lumen acidification. General stroma acidification can reduce electron movement through photosystem I and lumen acidification induces development of fluorescence non-photochemical quenching and reduces electron movement through photosystem II i.e. pH reduces in the stroma and lumen donate to the VP-induced ...
Immature scutella of barley were transformed with cDNA coding for a 13-li-poxygenase of barley (LOX-100) via particle bombardment. Regenerated plants were tested by PAT-assay, Western-analysis and PCR-screening. Immunocytochemical assay of T0 plants showed expression of the LOX cDNA both in the chloroplasts and in the cytosol, depending on the presence of the chloroplast signal peptide sequences in the cDNA. A few transgenic plants containing higher amounts of LOX-derived products have been found. These are the candidates for further analysis concerning pathogen resistance ...
Immature scutella of barley were transformed with cDNA coding for a 13-li-poxygenase of barley (LOX-100) via particle bombardment. Regenerated plants were tested by PAT-assay, Western-analysis and PCR-screening. Immunocytochemical assay of T0 plants showed expression of the LOX cDNA both in the chloroplasts and in the cytosol, depending on the presence of the chloroplast signal peptide sequences in the cDNA. A few transgenic plants containing higher amounts of LOX-derived products have been found. These are the candidates for further analysis concerning pathogen resistance ...
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Over the past ten years, work from our lab has identified mechanisms of chloroplast gene expression that have allowed for development of recombinant protein expression and metabolic engineering in the algal…. ...
Plants, Plant, Land Plants, Arabidopsis, Gene, Cell, Arabidopsis Thaliana, Chloroplast, Gene Expression, Proteins, Maize, Regulation, Cells, Chloroplasts, Genes, Light, Transcription Factors, Land Plant, Organelles, Angiosperms
Expression of most plastid genes involves multiple post-transcriptional processing events, such as splicing, editing, and intercistronic processing. The latter involves the formation of mono-, di-, an
9.A.62 The AAA-ATPase, Bcs1 (Bcs1) Family. The mitochondrial AAA-ATPase, Bcs1, mediates topogenesis of the Rieske protein, Rip1, a component of respiratory chains in bacteria, mitochondria, and chloroplasts (Wagener et al., 2011). The oligomeric AAA-ATPase Bcs1 is involved in export of the folded Fe-S domain of Rip1 across the inner membrane and insertion of its transmembrane segment into an assembly intermediate of the cytochrome bc1 complex. Structural elements in Rip1 are required for recognition and export by as well as ATP-dependent lateral release from the AAA-ATPase. In bacteria and chloroplasts Rip1 uses the Tat machinery for topogenesis; however, mitochondria have lost this machinery during evolution and a member of the AAA-ATPase family has taken over its function (Wagener et al., 2011). Mutations in Bcs1 lead to different properties of the protein and different disease-related symptoms (Wagener and Neupert 2012).. ...
But how about the genetics that determines number of stomata, allowing for passage of CO2 into the leaves, or loss of water. Do genetics influence the photosynthesis in stomata guard cells determining when they open or close? Chloroplast and mitochondria DNA influences the membrane structure of these organelles. Replication of chloroplasts and mitochondria must involve the interactions of genetics of these organelles with that of the host cells. Movement of minerals into cells and photosynthetic products out is partially determined by cell wall structures as influenced by genetics. Size and number of vascular bundles must be important to movement of water from roots to leaves and ears as well as carbohydrates from leaves to roots and ears ...
Principal Investigator:TAKAKI Mizuho, Project Period (FY):1993 - 1994, Research Category:Grant-in-Aid for General Scientific Research (C), Research Field:Functional biochemistry
The primary differences in the features of plant cells and animal cells are the presence or absence of a cell wall, chloroplasts and centrioles. Plant cells have cell walls and chloroplasts, while...
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Under rating threshold (hideshow) Heres a tip for the last level: 1.Do not produce any toxins and first build up lysosomes & peroxisomes & defensins. 2.Get 3x chloroplasts then 4x mitochondria. 3.Generate as much ATP as possible, youll really need it. And before you start thinking about moving on too soon, you need 50Gs worth, remember that you will use a lot just by looking around for it. 4.Recycle all of your chloroplasts for the fatty acids you will need. 5.Smack that toxin button 50 times. Assuming you did it correctly, all of the toxin will be created pretty much at the same time and you should win at the first virus wave . If you need a last-ditch effort because you didnt get enough ATP for the toxins - keep moving around the map, not only will this slow down viruses trying to attack you but youll get more G. remove , hide spam , reply ...
Learning Objectives To understand what it meant by oxidation and reduction in photosynthesis. To understand how ATP is made during the light-dependent reaction. To know the role of photolysis is in the light-dependent reaction. To understand how chloroplasts are adapted to carry out the light-dependent reaction.
Plant and Animal Cells. Nucleus - contains genetic material which controls the acitvites of the cell.. Cytoplasm - contains enzymes that control the chemical reactions which takes place here.. Cell membrane - holds cell together and controls what goes in and out.. Mitochondria - reactions for respiration take place. Repiration releases energy that cell needs to work.. Ribosomes - Proteins are made.. Plant cells have all of the above plus these extra bits below!. Cell wall - supports cell and strengthens it. Made of cellulose.. Permanent Vacuole - contains cell sap, weak solution of sugar and salts.. Chloroplasts - where photosynthesis occurs. Makes food for plant and contains chlorophyll. ...
Plant survival Titles and pictures Photosynthesis- Respiration- Transpiration- Photosynthesis ● Process by which they make this sugar. ● Chloroplasts, found in the cells of the leaf. ● A green pigment that absorbs the light energy. ● Plants use carbon dioxide fr. ...
it takes place in the chloroplast photosynthesis all energy starts comes from the sun co2 limiting factor and equation color wavelength 6CO2 + 6H2O +
Compare the structures and functions of plant and animal cells, including major organelles (cell membrane, cell wall, nucleus, chloroplasts, mitochondria, and vacuoles.) This lesson will begin our journey to understanding the structures and function of living organisms. We are starting at the building blocks of life - cells!
2.5.3 State that interphase is an active period in the life of a cell when many metabolic reactions occur, including protein synthesis, DNA replication and an increase in the number of mitochondria and/or chloroplasts ...
Interphase is an active period in the life of a cell when many metabolic reactions occur, including protein synthesis, DNA replication and an increase in the number of mitochondria and/or chloroplasts ...
Chemiosmotic coupling: The mechanism by which adenosine diphosphate|ADP is phosphorylated to adenosine triphosphate|ATP in mitochondria and chloroplast|...
Wettstein, D. V., Møller, Birger Lindberg, Høyer-Hansen, G. & Simpson, D. J., 1980, Origin of Chloroplasts. Schiff, J. A. & Stanier, R. Y. (red.). Amsterdam: Elsevier/North-Holland Biomedical Press, s. 243-255 13 s.. Publikation: Bidrag til bog/antologi/rapport › Bidrag til bog/antologi › Forskning › fagfællebedømt ...
Phototropins are UVA/blue-light receptors involved in controlling the light-dependent physiological responses which serve to optimize the photosynthetic activity of plants and promote growth. The phototropin-induced phosphoinositide (PI) metabolism has been shown to be essential for stomatal opening and phototropism. However, the role of PIs in phototropin-induced chloroplast movements remains poorly understood. The aim of this work is to determine which PI species are involved in the control of chloroplast movements in Arabidopsis and the nature of their involvement. We present the effects of the inactivation of phospholipase C (PLC), PI3-kinase (PI3K) and PI4-kinase (PI4K) on chloroplast relocations in Arabidopsis. The inhibition of the phosphatidylinositol 4,5-bisphospahte [PI(4,5)P2]-PLC pathway, using neomycin and U73122, suppressed the phot2-mediated chloroplast accumulation and avoidance responses, without affecting movement responses controlled by phot1. On the other hand, PI3K and PI4K ...
Photosynthetic development in any plant requires the intracellular co-ordination of chloroplast and nuclear gene expression programs. In this report, we investigate the role of a nuclear gene in photosynthetic development by examining C4 photosynthetic differentiation in a yellow mutant of maize (Zea mays L.). The plastids undifferentiated (pun) mutation disrupts plastid biogenesis in both bundle sheath and mesophyll cells, at an early developmental stage and in a light-independent manner. Chloroplast thylakoids are disrupted in the mutant and both membrane-associated and soluble chloroplast-encoded proteins accumulate at much reduced levels. The observed plastid morphology is consistent with a general defect in chloroplast biogenesis that is most likely exerted at the post-translational level. Despite aberrant chloroplast development, nuclear photosynthetic genes are expressed normally in pun mutants. Thus, neither functional chloroplasts nor the Pun gene product are required to establish nuclear
In recent years there has been extensive experimental evidence indicating that the nuclear expression of certain genes , in particular those that encode chloroplast proteins is subject to regulation by signals of retrograde plastid origin . This can be done both at the level of transcription and translation of mRNA . Certain plastid origin signals could be identified - these include metabolic precursor of chlorophyll plastochinonu redox state , thioredoxin and glutathione and phosphoenolpyruvate translocator located in the chloroplast inner envelope membrane . Identity plastid other signals , e.g., regulating cell differentiation and morphogenesis leaf remains unexplained . Signaling plastids - nucleus signaling and dependent on the light remain in a fairly complicated relationships , in some cases, are used for different transduction pathways , in others some of the same . Retrograde signaling is likely to be an important part of global regulatory networks that control metabolism and growth of ...
Photosynthetic organisms transform light energy into chemical potential, thereby providing the energy sources for nearly all life on Earth. The light reactions of oxygenic photosynthesis take place in thylakoids, a membrane system highly specialized for light energy capture, photosynthetic electron transfer reactions, and adenosine 5′-triphosphate (ATP) production (1). In plants, thylakoids are located in the chloroplast, an organelle of cyanobacterial origin. Two envelope membranes separate the chloroplast stroma, which is the aqueous phase surrounding the thylakoids, from the cytoplasm (2).. Photosynthetic electron transport generates highly reactive intermediates, which, in functional thylakoid membranes, are rapidly converted into more-stable intermediates to minimize production of unwanted byproducts, such as reactive oxygen species. Defects in thylakoid biogenesis have detrimental effects on plant viability (3, 4). The biogenesis of functional thylakoids requires the concerted interplay ...
Quercus is considered as one of the most important genera in the Northern Hemisphere as its economic and ecological importance. Oaks are taxonomically perplexing due to interspecific shared morphological traits and intraspecific morphological variation, which mainly attributed to hybridization. Universal plastid markers could not provide sufficient variable sites to explore the phylogeny of this genus and chloroplast genome-scale data proved to be useful to resolve intractable phylogenetic relationships. In this study, four complete chloroplast genomes of Quercus species were sequenced and one published chloroplast genomes of Q. baronii was retrieved for comparative analyses. The sizes of these five chloroplast genomes ranged from 161,072 bp (Q. baronii) to 161,237 bp (Q. dolicholepis), which has been identified the gene organization, gene order and GC content are similar to other published Fagaceae species. We analyzed the nucleotide substitution, indels and repeats in chloroplast genomes. The
The precursor for a Lemna light-harvesting chlorophyll a/b protein (pLHCP) has been synthesized in vitro from a single member of the nuclear LHCP multigene family. We report the sequence of this gene. When incubated with Lemna chloroplasts, the pLHCP is imported and processed into several polypeptides, and the mature form is assembled into the light-harvesting complex of photosystem II (LHC II). The accumulation of the processed LHCP is enhanced by the addition to the chloroplasts of a precursor and a co-factor for chlorophyll biosynthesis. Using a model for the arrangement of the mature polypeptide in the thylakoid membrane as a guide, we have created mutations that lie within the mature coding region. We have studied the processing, the integration into thylakoid membranes, and the assembly into light-harvesting complexes of six of these deletions. Four different mutant LHCPs are found as processed proteins in the thylakoid membrane, but only one appears to have an orientation in the membrane ...
The chloroplast genome (cp genome) encodes a set of proteins for photosynthesis and other house-keeping functions that are essential to plant development [1]. Cp genomes are often used for research on plant evolution. Furthermore, cp genomes are predominantly uniparentally inherited [2], have highly conserved gene content and quadripartite organisation, and consist of a large single copy (LSC), a small single copy (SSC) and two inverted copies (IRs). Therefore, cp genome is widely used to trace species history [3]-[6]. In the past several years, there has been a dramatic increase in the numbers of complete chloroplast genomes from higher plants [7]-[12]. To date, there have been 437 complete chloroplast genomes of plants deposited in the NCBI database, along with the emergence of next-generation sequencers. These database resources provide information to better understand cp genome evolution in land plants. The `living fossil Nelumbo Adans is a small genus of angiosperms with long evolutionary ...
C4 carbon fixation is the CO2 fixation mechanism used by the maize plant which harbors a kranz anatomy in its leaves. In maize it is carried out in two types of cells namely the mesophyll cell where Carbonic anhydrase fixes diffused CO2 to HCO3 and the enzyme PEP carboxylase converts HCO3 into oxaloacetic acid. Malate dehydrogenase catalyzes the conversion of oxaloacetic acid into malate in the mesophyll chloroplast. Malate is transported to the bundle sheath cell cytoplasm followed by the bundle sheath chloroplast where it is broken down into pyruvate and the CO2. This CO2 molecule is now fixed into 3-phosphoglycerate molecule by the active Rubisco enzyme. This process is different from the C3-carbon assimilation in rice which occurs only in the bundle sheath cells ...
A Chlamydomonas reinhardtii chloroplast expression vector, pACTBVP1, containing the fusion of the foot and mouth disease virus (FMDV) VP1 gene and the cholera toxin B subunit (CTB) gene was constructe
Shop Photosystem I reaction center ELISA Kit, Recombinant Protein and Photosystem I reaction center Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
TY - JOUR. T1 - Formate dehydrogenase in Arabidopsis thaliana. T2 - Overexpression and subcellular localization in leaves. AU - Herman, Patricia L.. AU - Ramberg, Håkon. AU - Baack, Renee D.. AU - Markwell, John. AU - Osterman, John C.. PY - 2002/12/1. Y1 - 2002/12/1. N2 - Formate dehydrogenase (FDH; EC 1.2.1.2) is a NAD-dependent enzyme that catalyzes the oxidation of formate to carbon dioxide in the mitochondria of higher plants. Sequence analyses and other preliminary experiments suggested that FDH might also be targeted to the chloroplasts of Arabidopsis thaliana and other plant species. In the present study, transgenic Arabidopsis and tobacco plants that overexpress Arabidopsis FDH were produced. The FDH specific activity in the leaf tissue of the transgenic plants increased an average of 4.5-fold for Arabidopsis and 31.5-fold for tobacco. Immunodetection and enzyme assays of intact chloroplasts fractionated from the leaves of transgenic tobacco plants suggested that Arabidopsis FDH is ...
Higher plant thylakoid membranes contain a protein kinase that phosphorylates certain threonine residues of light-harvesting complex II (LHCII), the main light-harvesting antenna complexes of photosystem II (PSII) and some other phosphoproteins (Allen, Biochim Biophys Acta 1098:275, 1992). While it has been established that phosphorylation induces a conformational change of LHCII and also brings about changes in the lateral organization of the thylakoid membrane, it is not clear how phosphorylation affects the dynamic architecture of the thylakoid membranes. In order to contribute to the elucidation of this complex question, we have investigated the effect of duroquinol-induced phosphorylation on the membrane ultrastructure and the thermal and light stability of the chiral macrodomains and of the trimeric organization of LHCII. As shown by small angle neutron scattering on thylakoid membranes, duroquinol treatment induced a moderate (~10%) increase in the repeat distance of stroma membranes, and ...

Euglena chloroplasts, SEM - Stock Image C036/0573 - Science Photo LibraryEuglena chloroplasts, SEM - Stock Image C036/0573 - Science Photo Library

Chloroplasts are the site of photosynthesis, the process that synthesises carbohydrates from carbon dioxide and water using ... Scanning electron micrograph (SEM) of a dying euglena releasing its chloroplasts (cyan). Euglena is a freshwater unicellular ... Caption: Euglena chloroplasts. Scanning electron micrograph (SEM) of a dying euglena releasing its chloroplasts (cyan). ... Keywords: biological, biology, cell, chlorophyll, chloroplast, coloured, euglena, false-coloured, flagellate., flora, grains, ...
more infohttp://www.sciencephoto.com/media/854306/view

Top page (E)Top page (E)

Kabeya, Y. and Miyagishima, S. (2013) Chloroplast DNA replication is regulated by the redox state independently of chloroplast ... Miyagishima,S., Suzuki, K., Okazaki, K., and Kabeya, Y. (2012) Expression of the nucleus-encoded chloroplast division genes and ... and dynamin-less chloroplast and non-photosynthetic plastid division Front. Plant Sci. 5:459. [Front. Plant Sci.] *[2014.8.21] ... DipM is required for peptidoglycan hydrolysis during chloroplast division. BMC Plant Biol. [BMC Plant Biol.] *[2013. 4.1] ...
more infohttps://www.nig.ac.jp/labs/SyCelEvo/All_topics_e.html

Adiantum - Study SolutionsAdiantum - Study Solutions

Each cell contains a single disc shaped chloroplast. The prothallus of Adiantum is completely independent. It can manufacture ... The epidermal cells have chloroplast. An undifferentiated layer of mesephyll cells is present between both epidermises. The ...
more infohttp://istudy.pk/adiantum/

Chloroplast - WikipediaChloroplast - Wikipedia

Most chloroplasts in plant cells, and all chloroplasts in algae arise from chloroplast division.[168] Picture references,[141][ ... Almost all chloroplasts in a cell divide, rather than a small group of rapidly dividing chloroplasts.[170] Chloroplasts have no ... Some chloroplasts contain a structure called the chloroplast peripheral reticulum.[108] It is often found in the chloroplasts ... Hoober, J. K. (1984). Chloroplasts. Plenum: New York. *^ a b c d e f g h i j Biology 8th Edition Campbell & Reece. Benjamin ...
more infohttps://en.wikipedia.org/wiki/Chloroplasts

Chloroplast origins | ScienceBlogsChloroplast origins | ScienceBlogs

Chris Taylor at Catalogue of Organisms has an absolutely stunning review of the origin of chloroplasts in eukaryotes. Its so ... Chris Taylor at Catalogue of Organisms has an absolutely stunning review of the origin of chloroplasts in eukaryotes. Its so ...
more infohttps://scienceblogs.com/evolvingthoughts/2009/05/06/chloroplast-origins

Green Genes Blasted into Chloroplasts | Science NewsGreen Genes Blasted into Chloroplasts | Science News

Science News was founded in 1921 as an independent, nonprofit source of accurate information on the latest news of science, medicine and technology. Today, our mission remains the same: to empower people to evaluate the news and the world around them. It is published by Society for Science & the Public, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education.. ...
more infohttps://www.sciencenews.org/archive/green-genes-blasted-chloroplasts

chloroplast - Everything2.comchloroplast - Everything2.com

Chloroplasts are a type of plastid found in algae and plants. These organelles contain chlorophyll and, in higher plants, ... For instance, the alga Spirogyra has very pretty helical ribbon-shaped chloroplasts. However, the chloroplasts of higher plants ... Inside a chloroplast, one finds a colorless gel called the stroma. The stroma is very similar to the matrix fluid of ... Sometimes, chloroplasts can lose their chlorophyll and they then become chromoplasts. References: Introductory Plant Biology by ...
more infohttps://everything2.com/title/chloroplast

2013: Chloroplasts | News | University of Bristol2013: Chloroplasts | News | University of Bristol

Plants let chloroplasts know the time. Investigating the effect of different wavelengths of light Antony Dodd/University of ... As chloroplasts are the site of photosynthesis, their function is highly dependent on the daily changes in light environment. ... Circadian Control of Chloroplast Transcription by a Nuclear-Encoded Timing Signal by Noordally, Z., Ishii, K., Atkins, K., ... A result of this is that chloroplasts have retained some of the cellular machinery required to produce proteins from their own ...
more infohttp://www.bris.ac.uk/news/2013/9204.html

Plant Chloroplast GenomePlant Chloroplast Genome

Structure of plant chloroplast genome. Martin F. Wojciechowski Click on an image to view larger version & data in a new window ... The complete chloroplast DNA sequence of the green alga Nephroselmis olivacea: Insights into the architecture of ancestral ... Physical and gene map of the green alga Nephroselmis chloroplast genome, showing the typical structural arrangement found in ... chloroplast genomes. Proceedings of the National Academy of Sciences USA 96: 10248-10253. ...
more infohttp://tolweb.org/notes/?note_id=4148

chloroplast inheritancechloroplast inheritance

... Christine D. Chase ctdc at GNV.IFAS.UFL.EDU Wed Oct 13 18:23:19 EST 1999 *Previous message: CUR list ...
more infohttp://www.bio.net/bionet/mm/plant-ed/1999-October/005178.html

Phys.org - chloroplastsPhys.org - chloroplasts

Chloroplasts are green because they contain the chlorophyll pigment. The word chloroplast (χλωροπλάστης) is derived from the ... Chloroplast. Chloroplasts (English pronunciation: /ˈklɒrəplæsts/) are organelles found in plant cells and other eukaryotic ... Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of ... Researchers map daffodils chloroplast genome for the first time. Gardeners might end up never planting the wrong bulb again ...
more infohttps://phys.org/tags/chloroplasts/

Do animal cells have chloroplasts? | Reference.comDo animal cells have chloroplasts? | Reference.com

Chloroplasts are food producers only found in the cells of a plants and a select number of... ... Animal cells do not have chloroplasts. Chloroplasts are food producers only found in the cells of a plants and a select number ... Chloroplasts take the light energy given off by the sun and convert it into sugars, which are used by the cells to help the ... Chloroplasts are just one main part of the process known as photosynthesis. ...
more infohttps://www.reference.com/science/animal-cells-chloroplasts-62af8acaa630a6df

chloroplast - Not Exactly Rocket Sciencechloroplast - Not Exactly Rocket Science

chloroplast. Not Exactly Rocket Science. Tag archives for chloroplast. Unintentional genetic engineering - grafted plants trade ...
more infohttp://scienceblogs.com/notrocketscience/tag/chloroplast/

Help! chloroplast isolationHelp! chloroplast isolation

... Zhu Congju medp4076 at leonis.nus.sg Tue Jun 25 04:02:15 EST 1996 *Previous message: ...
more infohttp://www.bio.net/bionet/mm/methods/1996-June/046151.html

Molecular Expressions Cell Biology: Plant Cell Structure - ChloroplastsMolecular Expressions Cell Biology: Plant Cell Structure - Chloroplasts

This process is carried out in specialized organelles called chloroplasts. ... Since, like mitochondria, chloroplasts possess their own genomes (DNA), the stroma contains chloroplast DNA and special ... Chloroplasts are one of several different types of plastids, plant cell organelles that are involved in energy storage and the ... The ellipsoid-shaped chloroplast is enclosed in a double membrane and the area between the two layers that make up the membrane ...
more infohttps://micro.magnet.fsu.edu/cells/chloroplasts/chloroplasts.html

ChloroplastChloroplast

Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. Chloroplasts absorb light ... chloroplasts are similar to mitochondria but chloroplasts are found only in plants and protista. The chloroplast is surrounded ... Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. Chloroplasts absorb light ... Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of ...
more infohttps://www.bionity.com/en/encyclopedia/Chloroplast.html

What Process Takes Place Inside Chloroplasts? | Reference.comWhat Process Takes Place Inside Chloroplasts? | Reference.com

Photosynthesis takes place inside of chloroplasts, which are inside plant cells. Photosynthesis is the process by which plants ... Photosynthesis takes place inside of chloroplasts, which are inside plant cells. Photosynthesis is the process by which plants ... Thylakoids are disc-like shapes that trap the sunlight for this purpose, which are stacked inside chloroplasts. The thylakoids ...
more infohttps://www.reference.com/science/process-takes-place-inside-chloroplasts-a0fc21f98e57d99

Chloroplast - New World EncyclopediaChloroplast - New World Encyclopedia

Chloroplasts are flat discs usually two to ten micrometers (μm) in diameter and one micrometer thick. The chloroplast has a two ... The fluid within the chloroplast is called the stroma. Although most of the chloroplasts proteins are encoded by genes ... in which a eukaryotic cell engulfed a second eukaryotic cell containing chloroplasts, forming chloroplasts with three or four ... The term chloroplast is derived from the Greek words chloros which means "green" and plast which means "form" ( in biological ...
more infohttp://www.newworldencyclopedia.org/entry/Chloroplast

Plant aging increases oxidative stress in chloroplasts.  - PubMed - NCBIPlant aging increases oxidative stress in chloroplasts. - PubMed - NCBI

This study provides new insights into the relationship between oxidative stress and plant aging, and points out chloroplasts as ... The results indicate that the oxidative stress associated with the aging in plants accumulates progressively in chloroplasts, ... Plant aging increases oxidative stress in chloroplasts.. Munné-Bosch S1, Alegre L. ... Enhanced formation of malondialdehyde in leaves (2.7-fold) and chloroplasts (2.8-fold), decreased photosynthetic activity (25 ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed/11925044?dopt=Abstract

2020 Mitochondria and Chloroplasts Conference GRC2020 Mitochondria and Chloroplasts Conference GRC

The 2020 Gordon Research Conference on Mitochondria and Chloroplasts will be held in West Dover, VT. Apply today to reserve ... Conference History Mitochondria and Chloroplasts (GRS) Contribute Financially to This Conference Conference Fees ... Each session of the GRC on Mitochondria and Chloroplasts will be introduced by an expert Discussion Leader who will provide a ... Mitochondria and chloroplasts differ from other cellular compartments by their endosymbiotic origin, their semiautonomous ...
more infohttps://www.grc.org/mitochondria-and-chloroplasts-conference/2020/

2006 Mitochondria and Chloroplasts Conference GRC2006 Mitochondria and Chloroplasts Conference GRC

The 2006 Gordon Research Conference on Mitochondria and Chloroplasts will be held in Oxford, United Kingdom. Apply today to ... "A New Route through the Secretory Pathway for Proteins Targeted to the Plant Chloroplast". ...
more infohttps://www.grc.org/mitochondria-and-chloroplasts-conference/2006/

Leaf Senescence and Transformation of Chloroplasts to Gerontoplasts | SpringerLinkLeaf Senescence and Transformation of Chloroplasts to Gerontoplasts | SpringerLink

Adam Z (1996) Protein stability and degradation in chloroplasts. Plant Mol Biol 32: 773-783PubMedCrossRefGoogle Scholar ... Liu X-Q and Jagendorf AT (1984) ATP dependent proteolysis in pea chloroplasts. FEBS Lett 166: 248-252CrossRefGoogle Scholar ... Andersson B and Aro E-M (1997) Proteolytic activities and proteases of plant chloroplasts. Physiol Plant 100: 780-793CrossRef ... Matile P (1992) Chloroplast senescence. In Baker N and Thomas H (eds) Crop Photosynthesis: Spatial and Temporal Determinants pp ...
more infohttps://link.springer.com/chapter/10.1007/978-94-007-1579-0_10

On the prokaryotic nature of red algal chloroplasts | PNASOn the prokaryotic nature of red algal chloroplasts | PNAS

On the prokaryotic nature of red algal chloroplasts. L Bonen and W F Doolittle ... The sequences of oligonucleotides released by T1 ribonuclease digestion of 32-P-labeled 16S (chloroplast) and 18S (cytoplasmic ... These data provide a measure of the evolutionary distance separating existing chloroplasts from contemporary bacteria and blue- ... There is extensive sequence homology between the Porphyridium chloroplast 16S ribosomal RNA and each of the prokaryotic 16S ...
more infohttp://www.pnas.org/content/72/6/2310

Re: what do sucrose usually do to chloroplasts?Re: what do sucrose usually do to chloroplasts?

... Date: Mon Jan 14 06:34:12 2008. Posted By: Eli Hestermann, Assistant Professor ... She said that sucrose is used as an osmotic stabilizer so that the chloroplast doesnt disintegrate. In other words, the buffer ...
more infohttp://www.madsci.org/posts/archives/2008-01/1200357505.Bc.r.html

WP 1.1 chloroplast metabolismWP 1.1 chloroplast metabolism

Chloroplast metabolism (WP1.1). Chloroplasts are the plant cell organelles containing chlorophyll. By means of photosynthesis ... Finally, chloroplasts can be used to harvest organic Vitamin E and K, which are best known for their antioxidant properties in ... The products of these genes may act on the positioning of chloroplasts but also on the orientation of the plant towards the ... Furthermore, chloroplasts have exceptional potential for the biosynthesis of pharmaceutical molecules, such as insulin for ...
more infohttps://www.unine.ch/nccr/home/forschung-2009-2013/wp-11-stoffwechsel-der-chloropla.html
  • Physical and gene map of the green alga Nephroselmis chloroplast genome, showing the typical structural arrangement found in land plants. (tolweb.org)
  • Gardeners might end up never planting the wrong bulb again after the Royal Horticultural Society (RHS) and Reading University successfully mapped a daffodil's chloroplast genome for the first time. (phys.org)
  • Chloroplasts have their own genome, which is considerably reduced compared to that of free-living cyanobacteria, but the parts that are still present show clear similarities with the cyanobacterial genome. (bionity.com)
  • Most chloroplasts have their entire chloroplast genome combined into a single large ring, though those of dinophyte algae are a notable exception-their genome is broken up into about forty small plasmids , each 2,000-10,000 base pairs long. (wikipedia.org)
  • It is possible that the inverted repeats help stabilize the rest of the chloroplast genome, as chloroplast DNAs which have lost some of the inverted repeat segments tend to get rearranged more. (wikipedia.org)
  • Adapted from Krishnan NM, Rao BJ's paper "A comparative approach to elucidate chloroplast genome replication. (wikipedia.org)
  • Without light, photosynthesis, the reaction by which the plant chloroplasts convert atmospheric CO2 and water into sugars and oxygen, cannot take place. (phys.org)
  • Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis. (phys.org)
  • Chloroplasts take the light energy given off by the sun and convert it into sugars, which are used by the cells to help the plant stay healthy and grow. (reference.com)
  • Chloroplasts may seem like docile farmers of light. (sciencenews.org)
  • In response to low or high intensities of light, the chloroplasts in the mesophyll cells of the leaf are able to increase or decrease their exposure to light by accumulating at the upper and lower sides or along the side walls of the cell respectively. (springer.com)
  • Inoue Y, Shibata K (1973) Light-induced chloroplast rearrangements and their action spectra as measured by absorption spectrophotometry. (springer.com)
  • Kadota A, Sato Y, Wada M (2000) Intracellular chloroplast photorelocation in the moss Physcomitrella patens is mediated by phytochrome as well as by a blue-light receptor. (springer.com)
  • Nonetheless, there are a number of prokaryotic traits that chloroplasts continue to exhibit. (fsu.edu)
  • There is extensive sequence homology between the Porphyridium chloroplast 16S ribosomal RNA and each of the prokaryotic 16S ribosomal RNAs, but little homology between the Porphyridium cytoplasmic 18S ribosomal RNA and any of the 16S species. (pnas.org)
  • The process causes modifications in mitochondrial cristae, condensation of the nucleus, shrinkage of chloroplasts and extensive alteration of thylakoid structure. (springer.com)
  • Chloroplasts are observable morphologically as flat discs usually 2 to 10 micrometer in diameter and 1 micrometer thick. (bionity.com)
  • Chloroplasts are flat discs usually two to ten micrometers (μm) in diameter and one micrometer thick. (newworldencyclopedia.org)
  • Despite this, chloroplasts can be found in an extremely wide set of organisms, some not even directly related to each other-a consequence of many secondary and even tertiary endosymbiotic events . (wikipedia.org)
  • Bozkurt says he was shocked by how dynamic the chloroplasts' reaction was. (sciencenews.org)
  • Scientists have attempted to observe chloroplast replication via electron microscopy since the 1970s. (wikipedia.org)
  • Students observe chloroplasts directly under the microscope using a plant such as Elodea pondweed. (saps.org.uk)
  • Plant cells communicate information about the time of day to their chloroplasts, the part of their cells that underpins all agricultural productivity on Earth, researchers at the University of Bristol have demonstrated in a study published today in Science. (bris.ac.uk)
  • In experiments, when researchers silenced the gene for CHUP1, chloroplasts mostly didn't respond to an infection. (sciencenews.org)
  • This process occurs in almost all plant species and is carried out in specialized organelles known as chloroplasts. (fsu.edu)
  • Chloroplasts are green and come in various sizes (2 to 10 micrometer s in diameter ) and shapes. (everything2.com)
  • The chloroplasts surround the haustorium, releasing toxic chemicals and appearing to crush the invader. (sciencenews.org)