Moss chloroplasts should prove useful for studying the cyanobacteria-derived system in chloroplasts. To determine the effects of antibiotics that inhibit bacterial peptidoglycan synthesis, the numbers of chloroplasts in treated Physcomitrella patens cells were counted. Ampicillin and d-cycloserine caused a rapid decrease in the number of chloroplasts per cell. Fosfomycin affected half of the cells, while vancomycin affected a few cells. Conversely, bacitracin had no effect. With the decrease in chloroplast number, macrochloroplasts appeared in antibiotic-treated cells. Removal of the antibiotics resulted in the recovery of chloroplast number, suggesting that the decrease in number was directly dependent on the antibiotic treatment. Microscopic observations showed that the decrease in the number of chloroplasts resulted from cell division without chloroplast division. These results suggest that enzymes derived from the bacterial peptidoglycan synthesis pathway are related to moss chloroplast ...

The data presented here suggest that 3′ end processing may be required for translation of atpB and rbcLmRNAs in Chlamydomonas chloroplasts. Unprocessed atpB transcripts, defined as those that do not accumulate as an abundant size class of approximately 2 kb, were only present in nonpolysomal fractions. Processed mRNAs were present in both polysomal and nonpolysomal fractions. Since the 3′ ends of most chloroplast transcripts are generated from longer pre-mRNAs by exo- and/or endonucleolytic mechanisms (17, 36, 37, 44, 47), this 3′ processing apparatus may interact with or signal the translational machinery.. Our ability to detect a heterogeneous collection of putative processing intermediates or incorrectly processed transcripts for atpBand rbcL suggests that these molecules are relatively stable in the chloroplast. When they were analyzed by RNase protection, it was possible to detect partially processed transcripts in theChlamydomonas chloroplast petD-trnR region (29), and in certain ...

TY - THES. T1 - Utilization of complete chloroplast genomes for phylogenetic studies. AU - Ramlee, Shairul Izan Binti. N1 - WU thesis 6484 Includes bibliographic references. - With summary in English. PY - 2016. Y1 - 2016. N2 - Chloroplast DNA sequence polymorphisms are a primary source of data in many plant phylogenetic studies. The chloroplast genome is relatively conserved in its evolution making it an ideal molecule to retain phylogenetic signals. The chloroplast genome is also largely, but not completely, free from other evolutionary processes such as gene duplication, concerted evolution, pseudogene formation and genome rearrangements. The conservation of the chloroplast genome sequence allows designing primers targeting regions conserved well beyond species boundaries, and amplification of these targets. The small size together with their high copy number in leaf cells greatly facilitates chloroplast genome sequencing. In this thesis, chloroplast phylogenomics was conducted using complete ...

Chloroplast glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is composed of two different subunits, GAPA and GAPB, which are encoded in the nucleus by two related genes of eubacterial origin. In the present work the genes encoding chloroplast GAPA and GAPB from pea have been cloned and sequenced. The gene for GAPB is split by eight introns. Two introns interrupt the region encoding the transit peptide and six are found within the region encoding the mature subunit, four of which are in identical or similar positions relative to genes for cytosolic GAPDH of eukaryotic organisms. As opposed to this, the gene encoding pea GAPA has only two introns in the region encoding the mature subunit. These findings strongly support the intron early hypothesis and suggest that the low number of introns in the gene for chloroplast GAPA is due to differential loss of introns during the streamlining period of the chloroplast genome following the GAPB/GAPA separation. We deduce from this that eubacteria and ...

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 leaves and intact chloroplasts, oxidation and reduction have been shown previously to regulate the ATPase activity of thylakoids. Illumination of spinach chloroplast thylakoids in the presence of dithiothreitol, which activates the ability of thylakoids to catalyze sustained ATP hydrolysis in the dark, causes increased incorporation of N-ethylmaleimide into the gamma subunit of coupling factor 1 (CF1). A disulfide bond in the gamma subunit is reduced during activation. The residues involved in this disulfide bond are the same as those in the disulfide linkage reduced during dithiothreitol activation of soluble CF1. The disulfide and dithiol forms of the gamma subunit may be separated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. N-Ethylmaleimide is preferentially incorporated in the dark into the reduced form of the gamma subunit of CF1 in thylakoids previously exposed to dithiothreitol. Only a subpopulation of the CF1 in thylakoids is susceptible to ...

TY - JOUR. T1 - The level of stromal ATP regulates translation of the D1 protein in isolated chloroplasts. AU - Kuroda, Hiroshi. AU - Inagaki, Noritoshi. AU - Satoh, Kimiyuki. PY - 1992/1/1. Y1 - 1992/1/1. N2 - The synthesis of the D1 subunit of the reaction center of photosystem II is light-dependent in isolated chloroplasts. The mechanism of the regulation by light was analyzed using spinach chloroplasts. The light-regulated synthesis of the D1 protein was prevented by the addition of atrazine and the dependence on the concentration of atrazine of the inhibition was practically identical with that of the inhibition of photosynthetic electron transport in photosystem II, as measured by the photoreduction of 2,6-dichlorophenol indophenol. Inhibitors of photosynthetic phosphorylation, such as phloridzin, nigericin and carbonyl cyanide m-chlorophenylhydrazone, also inhibited the light-dependent synthesis of the D1 protein. Determination of the levels of ATP in chloroplasts and the rates of ...

Background At present, plant molecular systematics and DNA barcoding techniques rely heavily on the use of chloroplast gene sequences. Because of the relatively low evolutionary rates of chloroplast genes, there are very few choices suitable for molecular studies on angiosperms at low taxonomic levels, and for DNA barcoding of species. Methodology/Principal Findings We scanned the entire chloroplast genomes of 12 genera to search for highly variable regions. The sequence data of 9 genera were from GenBank and 3 genera were of our own. We identified nearly 5% of the most variable loci from all variable loci in the chloroplast genomes of each genus, and then selected 23 loci that were present in at least three genera. The 23 loci included 4 coding regions, 2 introns, and 17 intergenic spacers. Of the 23 loci, the most variable (in order from highest variability to lowest) were intergenic regions ycf1-a, trnK, rpl32-trnL, and trnH-psbA, followed by trnSUGA-trnGUCC, petA-psbJ, rps16-trnQ, ndhC-trnV, ycf1

TY - JOUR. T1 - Light- and metabolism-related regulation of the chloroplast ATP synthase has distinct mechanisms and functions. AU - Kohzuma, Kaori. AU - Dal Bosco, Cristina. AU - Meurer, Jörg. AU - Kramer, David M.. PY - 2013/5/3. Y1 - 2013/5/3. N2 - The chloroplast CF0-CF1-ATP synthase (ATP synthase) is activated in the light and inactivated in the dark by thioredoxin-mediated redox modulation of a disulfide bridge on its γ subunit. The activity of the ATP synthase is also fine-tuned during steady-state photosynthesis in response to metabolic changes, e.g. altering CO2 levels to adjust the thylakoid proton gradient and thus the regulation of light harvesting and electron transfer. The mechanism of this fine-tuning is unknown. We test here the possibility that it also involves redox modulation. We found that modifying the Arabidopsis thaliana γ subunit by mutating three highly conserved acidic amino acids, D211V, E212L, and E226L, resulted in a mutant, termed mothra, in which ATP synthase ...

Genetic improvement of agronomic crops is necessary to cope with chilling stress. To identify the physiological factors responsible for this genotypic difference in chill-induced inhibition of photosynthesis, leaf CO2 assimilation, the electron flux in the chloroplast and the antioxidant metabolism in isolated chloroplasts were examined in two genotypes of cucumber (Cucumis sativus) plants with distinct chilling tolerance. Cucumber plants were exposed to 100 µmol m-2 s-1 at 9/7°C (day/night) for 10 d and were then returned to optimal conditions for 2 d. Chilling resulted in more significant reductions in rbcL and rbcS transcripts, ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) content and initial Rubisco activity, leading to higher electron flux to O2 in the chilling-sensitive genotype than in the chilling-tolerant genotype. The chilling-tolerant genotype showed lower H2O2 contents in the chloroplasts by maintaining higher H2O2-scavenging activity in the chloroplasts than in the ...

Plastids are plant cell organelles that each form an enclosed compartment containing ∼3000 different protein species, depending on the developmental stage and tissue-specific differentiation (Sun et al., 2004; Leister, 2016). While a small fraction of plastid proteins are encoded on the plastid genome, most are encoded on the nuclear genome as preproteins with an N-terminal transit peptide and imported posttranslationally through the translocons at the outer (TOC) and inner (TIC) chloroplast envelope membranes (Jarvis, 2008; Li and Chiu, 2010; Shi and Theg, 2013; Demarsy et al., 2014; Paila et al., 2015). Plastid targeting specificity is conferred by the Toc34 and Toc159 families of TOC receptors in the outer plastid membrane, which can specifically interact with the transit peptides of preproteins. Each preprotein is then threaded through adjacent TOC and TIC channels in the outer and inner envelope membranes. The transit peptide is cleaved off by the stromal processing peptidase when the ...

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 ...

1. Gray, J.C., Genetic manipulation of the chloroplast genome, Biotechnology, 1989, vol. 12, no. 14, pp. 317 335.. 2. Howe, C.J., Barbrook, A.C., Koumandou, V.L., Nisbet, R.E., and Symington, H.A., Evolution of the chloroplast genome, Philos. Trans. R. Soc. Lond., B. Biol. Sci., 2003, vol. 358, no. 1429, pp. 99 107. https://doi.org/10.1098/rstb.2002.1176. 3. Jansen, R.K., Cai, Z.Q., Raubeson, L.A., Daniell, H., Depamphilis, C.W., Leebens-Mack, J., Müller, K.F., Guisinger-Bellian, M., Haberle, R.C., Hansen, A.K., Chumley, T.W., Lee, S.B., Peery, R., McNeal, J.R., Kuehl, J.V., and Boore, J.L., Analysis of 81 genes from 64 plastid genomes resolves relationships in angiosperms and identifies genome-scale evolutionary patterns, Proc. Natl. Acad. Sci. U. S. A., 2007, vol. 104, no. 49, pp. 19369 19374. https://doi.org/10.1073/pnas.0709121104. 4. Odintsova, M.S. and Yurina, N.P., Chloroplast genomics of land plants and algae, Biotechnol. Appl. Photosyn. Protein: Biochips, Biosensors, Biodevices, 2006, ...

CONIFER CHLOROPLAST GENOMES (NEARLY) SEQUENCED ????? To date a number of chloroplast genomes have been sequenced. A few years ago there were plans to sequence the entire chloroplast genome from a conifer. Has anybody got any news about what has been done to date in this regard? Id appreciate any information. peter sibbald at EMBL-Heidelberg.DE ...

TY - JOUR. T1 - Characteristics of ribulose-1,5-bisphosphate carboxylase/oxygenase degradation by lysates of mechanically isolated chloroplasts from wheat leaves. AU - Miyadai, Kenji. AU - Mae, Tadahiko. AU - Makino, Amane. AU - Ojima, Kunihiko. PY - 1990/4. Y1 - 1990/4. N2 - The lysate from intact chloroplasts mechanically isolated from primary leaves of 9 day old seedlings of wheat (Triticum aestivum L. var Aoba) was incubated in the pH range of 5.5 to 8.5 at 37°C for 5 hours. Proteolytic activity against ribulose-1.5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) was estimated by disappearance of the large subunit of Rubisco or the appearance of its degradation products. Although the activity in lysates was weak, the products were detected by applying Western blotting. The degradation products were similar to those obtained when Rubisco was incubated with the lysate of vacuoles isolated from like leaves. Although some of the products were similar to those from vacuole lysates, ...

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 ...

A 2.4 kb region of theEuglena gracilis chloroplast genome containing the genespsbT, psbH andpsbN was characterized. The mRNAs transcribed frompsbB, psbT, p

1. Stern, D. B., Goldschmidt-Clermont, M., and Hanson, M. R. (2010) Chloroplast RNA metabolism. Annual Rev Plant Biol 61, 125-155.. 2. Reed, M. L., and Hanson, M. R. (1997) A heterologous maize rpoB editing site is recognized by transgenic tobacco chloroplasts. Mol Cell Biol 17, 6948-6952.. 3. Reed, M. L., Lyi, S. M., and Hanson, M. R. (2001) Edited transcripts compete with unedited mRNAs for trans-acting editing factors in higher plant chloroplasts. Gene 272, 165-171.. 4. Reed, M. L., Peeters, N. M., and Hanson, M. R. (2001) A single alteration 20 nt 5 to an editing target inhibits chloroplast RNA editing in vivo. Nucleic Acids Res 29, 1507-1513.. 5. Hegeman, C. E., Hayes, M. L., and Hanson, M. R. (2005) Substrate and cofactor requirements for RNA editing of chloroplast transcripts in Arabidopsis in vitro. Plant Journal 42, 124-132.. 6. Heller, W. P., Hayes, M. L., and Hanson, M. R. (2008) Cross-competition in editing of chloroplast RNA transcripts in vitro implicates sharing of trans-factors ...

A protein kinase was found in envelope membranes of purified pea (Pisum sativum L.) chloroplasts. Separation of the two envelope membranes showed that most of the enzyme activity was localized in the outer envelope. The kinase was activated by Mg2+ and inhibited by ADP and pyrophosphate. It showed no response to changes in pH in the physiological range (pH 7-8) or conventional protein substrates. Up to ten phosphorylated proteins could be detected in the envelope-membrane fraction. The molecular weights of these proteins, as determined by polyacrylamide-gel electrophoresis were: two proteins higher than 145 kDa, 97, 86, 62, 55, 46, 34 and 14 kDa. The 86-kDa band being the most pronounced. Experiments with separated inner and outer envelopes showed that most labeled proteins are also localized in the outer-envelope fraction. The results indicate a major function of the outer envelope in the communication between the chloroplast and the parent cell. ...

Plants employ a variety of mechanisms to maximize photosynthetic potential under changing environmental conditions. For example, most plants can biochemically adapt to excessive light by altering the size of light harvesting complexes, dissipating excess energy as heat, scavenging reactive oxygen, and rapidly repairing damaged reaction center proteins (Niyogi, 1999). Developmental changes that occur in response to different light conditions include variations in leaf thickness, density of mesophyll cells, and changes in the orientation of the leaf blade (Boardman, 1977). These responses have been associated with improved photosynthetic potential and/or protection from photodamage. However, their relative importance can be species specific, indicating that some of these responses represent unique adaptive strategies. Another perhaps more ubiquitous plant response to varying light conditions is light-induced chloroplast movement, which has been documented in a large number of species, including ...

Physical and gene map of the green alga Nephroselmis chloroplast genome, showing the typical structural arrangement found in land plants. Genes located on the inside of the map are transcribed counterclockwise, and genes on the outside are transcribed clockwise. The inner circle shows where the Small Single-Copy region (SSC), Large Single Copy region (LSC) and Inverted Repeats (IR), are located. The thick lines on the actual map are the IRs. Figure from Turmel et al. (1999). © 1999 National Academy of Sciences, U.S.A. The B copy (IR-B) of the inverted repeat is the copy that is missing in legume taxa in the IRLC.. ...

Mesophyll chloroplasts from sodium-deficient compared to normal plants of the C4 species Kochia childsii and Amaranthus tricolor were found to have significantly less stacking in their grana. On the other hand, no marked difference of thylakoid arrangement between bundle sheath chloroplasts from sodium-deficient and normal plants of A. tricolor were observed.. ...

TY - JOUR. T1 - Faithful editing of a tomato-specific mRNA editing site in transgenic tobacco chloroplasts. AU - Karcher, D.. AU - Kahlau, Sabine. AU - Bock, R.. PY - 2008. Y1 - 2008. N2 - RNA editing sites and their site-specific trans-acting recognition factors are thought to have coevolved. Hence, evolutionary loss of an editing site by a genomic mutation is normally followed by the loss of the specific recognition factor for this site, due to the absence of selective pressure for its maintenance. Here, we have tested this scenario for the only tomato-specific plastid RNA editing site. A single C-to-U editing site in the tomato rps12 gene is absent from the tobacco and nightshade plastid genomes, where the presence of a genomic T nucleotide obviates the need for editing of the rps12 mRNA. We have introduced the tomato editing site into the tobacco rps12 gene by plastid transformation and find that, surprisingly, this heterologous site is efficiently edited in the transplastomic plants. This ...

Species of Bryopsidales form ecologically important components of seaweed communities worldwide. These siphonous macroalgae are composed of a single giant tubular cell containing millions of nuclei and chloroplasts, and harbor diverse bacterial communities. Little is known about the diversity of chloroplast genomes (cpDNAs) in this group, and about the possible consequences of intracellular bacteria on…

Ferredoxin-NADP+-oxidoreductase (FNR) is a FAD-containg enzyme found both in the chloroplasts and non-photosynthetic plastids of higher plants. In chloroplasts, FNR has a well-defined role in linear electron flow, and in the root plastids, FNR is needed for nitrogen metabolism. In Arabidopsis thaliana, FNR is encoded by a gene family: At1g30510 and At4g05390 encode the root isozyme of FNR and At5g66190 and At1g20020 encode the leaf/chloroplast isozyme, which share a high degree of homology. Since FNR is a crucial determinant for the acclimation of the photosynthetic machinery, we have recently focused on resolving the specific physiological roles of the two distinct chloroplast-targeted FNR isoforms using the Arabidopsis fnr knock-out mutants (Lintala et al. 2007; 2009; 2012). We have also resolved the binding partner and the physiological significance of FNR shuttling within the chloroplast (Benz et al. 2009; 2010; Lintala et al.2014), and established differential drought stress -induced ...

Plastid-to-nucleus retrograde signaling coordinates nuclear gene expression with chloroplast function and is essential for the photoautotrophic life-style of plants. Three retrograde signals have been described, but little is known of their signaling pathways. We show here that GUN1, a chloroplast-localized pentatricopeptide-repeat protein, and ABI4, an Apetala 2 (AP2)-type transcription factor, are common to all three pathways. ABI4 binds the promoter of a retrograde-regulated gene through a conserved motif found in close proximity to a light-regulatory element. We propose a model in which multiple indicators of aberrant plastid function in Arabidopsis are integrated upstream of GUN1 within plastids, which leads to ABI4-mediated repression of nuclear-encoded genes. |P /|

What is a plastid Cell | Process of Photosynthesis | Chloroplasts, chromoplast, leucoplasts & Other Plastids. Learn more about [email protected]

Kelly, A. A.; Kalisch, B.; Hoelzl, G.; Schulze, S.; Thiele, J.; Melzer, M.; Roston, R. L.; Benning, C.; Doermann, P.: Synthesis and transfer of galactolipids in the chloroplast envelope membranes of Arabidopsis thaliana. Proceedings of the National Academy of Sciences of the United States of America 113 (38), S. 10714 - 10719 (2016 ...

Biology. Physical Sciences. Science and Industry. M.Sc. Bio Technology: Chloroplast Engineering in Orissa. M.Sc. Bio Technology: Chloroplast Engineering. The University at Jyoti Vihar provides Post-Graduate education in Twenty-seven subjects through Twenty Post-Graduate Departments. The University Post-Graduate Departments offer one-year study Programme

Substitutions occurring in noncoding sequences of the plant chloroplast genome violate the independence of sites that is assumed by substitution models in molecular evolution. The probability that a substitution at a site is a transversion, as opposed to a transition, increases significantly with in …

Studte, Carsten (2012): Characterization of the membrane protein Prat1 in the inner envelope of chloroplasts. Dissertation, LMU München: Faculty of Biology ...

Houben, E., Nilsson, R., de Gier, J.W., Brunner, J., Hoffman, N.E. and van Wijk, K.J. (1999) Reconstitution of co-translational targeting of polytopic membrane proteins to the thylakoids in a homologous chloroplast translation system. In: NATO advanced research workshop. The Chloroplast; From Molecular Biology to Biotechnology. (Dr. J. Argyroudi-Akoyunoglou and H. Senger, eds.), 327- ...

FtsH is an evolutionary conserved membrane-bound metalloprotease complex. While in most prokaryotes FtsH is encoded by a single gene, multiple FtsH genes are found in eukaryotes. Genetic and biochemical data suggest that the Arabidopsis chloroplast FtsH is a hetero-hexamer. This raises the question why photosynthetic organisms require a heteromeric complex, whereas in most bacteria a homomeric one is sufficient. To gain structural information of the possible complexes, the Arabidopsis FtsH2 (type B) and FtsH5 (type A) were modeled. An in silico study with mixed models of FtsH2/5 suggests that heteromeric hexamer structure with ratio of 4∶2 is more likely to exists. Specifically, calculation of the buried surface area at the interfaces between neighboring subunits revealed that a hetero-complex should be thermodynamically more stable than a homo-hexamer, due to the presence of additional hydrophobic and hydrophilic interactions. To biochemically assess this model, we generated Arabidopsis transgenic

Unknown protein; FUNCTIONS IN: molecular_function unknown; INVOLVED IN: biological_process unknown; LOCATED IN: chloroplast thylakoid membrane, chloroplast thylakoid lumen, chloroplast; EXPRESSED IN: 22 plant structures; EXPRESSED DURING: 13 growth /.../; Has 38 Blast hits to 38 proteins in 13 species: Archae - 0; Bacteria - 0; Metazoa - 0; Fungi - 0; Plants - 38; Viruses - 0; Other Eukaryotes - 0 (source: NCBI BLink ...

Figure 1: Model of dual function of the pyruvate dehydrogenase complex. In this project, we aim at elucidating the precise molecular working mode of this regulatory principle involving metabolic control of gene expression. By following molecular, genetical, and biochemical approaches in C. reinhardtii, we use in vivo and in vitro techniques to characterize both the RNA binding and the enzymatic forms of DLA2 which appears to shuttle between different protein sub-complexes. A special focus is on the dynamics and composition of these complexes and the role of acetate/acetyl-CoA for balancing both functions of DLA2. This work is complemented by related analyses in cyanobacteria and higher plants, to test for an evolutionary conservation of such a regulatory switch.. A second project is based on recent work from our group that has shown that in C. reinhardtii the translation of the psbD mRNA encoding the D2 protein of PSII is redox-regulated via a single disulphide bridge between the trans-acting ...

Extranuclear inheritance or cytoplasmic inheritance is the transmission of genes that occur outside the nucleus. It is found in most eukaryotes and is commonly known to occur in cytoplasmic organelles such as mitochondria and chloroplasts or from cellular parasites like viruses or bacteria. Mitochondria are organelles which function to transform energy as a result of cellular respiration. Chloroplasts are organelles which function to produce sugars via photosynthesis in plants and algae. The genes located in mitochondria and chloroplasts are very important for proper cellular function, yet the genomes replicate independently of the DNA located in the nucleus, which is typically arranged in chromosomes that only replicate one time preceding cellular division. The extranuclear genomes of mitochondria and chloroplasts however replicate independently of cell division. They replicate in response to a cells increasing energy needs which adjust during that cells lifespan. Since they replicate ...

Escherichia coli minicells harbouring the cloned restriction fragment Sall S9 from P. hybrida chloroplast DNA synthesize the beta and epsilon polypeptide subuni

TY - JOUR. T1 - Nucleotide sequence of the chloroplast 16S rRNA gene from pea (Pisum sativum L.). AU - Cerutti, H.. AU - Jagendorf, A. T.. PY - 1991/7/1. Y1 - 1991/7/1. UR - http://www.scopus.com/inward/record.url?scp=0026196725&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0026196725&partnerID=8YFLogxK. U2 - 10.1007/BF00036812. DO - 10.1007/BF00036812. M3 - Article. C2 - 1868211. AN - SCOPUS:0026196725. VL - 17. SP - 125. EP - 126. JO - Plant Molecular Biology. JF - Plant Molecular Biology. SN - 0167-4412. IS - 1. ER - ...

Molecular phyl葉緑体rbcL遺伝子に基づく蘚類ギボウシゴケ目の分子系統学的研究ogeny of the Grimmiales (Musci) based on chloroplast rbcL sequences, Hikobia, 14巻, 1号, pp.55-pp. ...

The subspecies of Physaria kingii (S. Watson) OKane and Al-Shehbaz (Brassicaceae) have historically been a difficult group to delimit taxonomically based on morphology, geography, and ecology. The taxa have been moved between genera as well among varieties, subspecies, and full species many times over. This study addressed the systematics relationships of the subspecies of P. kingii using a combination of molecular (both nuclear and chloroplast DNA sequences), morphological, geographical, and ecological data. Three non-coding DNA regions were chosen: the internal transcribed spacer (ITS) region of nuclear ribosomal DNA and the chloroplast rps intron and the chloroplast ndhC-trnV intergenic spacer. Eighty-seven aligned sequences in total were selected and networks were constructed using SplitsTree for exploratory data analyses to identify any genealogical discordance for each of the regions in addition to a combined chloroplast region. With the prior knowledge of possible hybridization among P. k. subsp

Postglacial migration is a major factor responsible for the patterns of genetic variation we see in natural populations. Fossil pollen data indicate that early postglacial colonists such as oak, were able to take both western and eastern migration routes into Britain. Analysis at a finer level is now permitted by the use of modern molecular techniques. A 13-bp duplication in the chloroplast tRNALeul intron occurs in natural populations of East Anglian oaks, but is not found in other parts of Britain or from mainland Europe. The distribution of this marker suggests that the mutation occurred either in southern England, or during migration from the mainland, and became fixed in a source population from which East Anglia was colonized. Planting of non-native trees for roadside boundaries and in the grounds of old houses and estates, explains the absence of the marker from some East Anglian oaks.. ...

Plants need sunlight to feed and grow. Without light, the photosynthesis, the reaction by which the plant chloroplasts convert atmospheric CO2 and water into sugars and oxygen, cannot take place.

if you inject a chloroplast into an animal cell it will go through autophagocytosis because the cell iterprets it like foreign. in order for a chloroplast to function it must be in a plant cell because some genes, during evolution some genes were transfered between the chloroplast genome and the nucleus. However that would not happen as the cell would probably treat a foreign chloroplast or a foreign nucleus as foreign and digest it. Another possibility is for the cell to undergo apoptosis. Unfortunaly, i dont enough biology to answer such a complex question. Sorry ...

In this study we report the development of primers to amplify polymorphic chloroplast simple sequence repeats in the genus Hordeum, which includes cultivated barley (H. vulgare ssp. vulgare) and its wild progenitor H. vulgare ssp. spontaneum. Polymorphic products were amplified in a wide range of Hordeum spp. and intraspecific variation was detected in both cultivated and wild barley. A decrease in cytoplasmic diversity was observed between sspp. spontaneum and vulgare as well as between ssp. vulgare landraces and cultivars, which is characteristic of domestication processes in many crop species. We also observed possible evidence for reticulate evolution of H. brachyantherum polyploids, with apparent multiple cytoplasmic introgressions during successive polyploidization events. ...

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

Oncidium spp. produce commercially important orchid cut flowers. However, they are amenable to intergeneric and inter-specific crossing making phylogenetic identification very difficult. Molecular markers derived from the chloroplast genome can provide useful tools for phylogenetic resolution. The complete chloroplast genome of the economically important Oncidium variety Onc. Gower Ramsey (Accession no. GQ324949) was determined using a polymerase chain reaction (PCR) and Sanger based ABI sequencing. The length of the Oncidium chloroplast genome is 146,484 bp. Genome structure, gene order and orientation are similar to Phalaenopsis, but differ from typical Poaceae, other monocots for which there are several published chloroplast (cp) genome. The Onc. Gower Ramsey chloroplast-encoded NADH dehydrogenase (ndh) genes, except ndhE, lack apparent functions. Deletion and other types of mutations were also found in the ndh genes of 15 other economically important Oncidiinae varieties, except ndhE in some species

Environmental concerns over the cultivation of Genetically Modified (GM) crops largely centre on the ecological consequences following gene flow to wild relatives. One attractive solution is to deploy biocontainment measures that prevent hybridization. Chloroplast transformation is the most advanced biocontainment method but is compromised by chloroplast capture (hybridization through the maternal lineage). To date, however, there is a paucity of information on the frequency of chloroplast capture in the wild. Oilseed rape (Brassica napus, AACC) frequently hybridises with wild Brassica rapa (AA, as paternal parent) and yields B. rapa-like introgressed individuals after only two generations. In this study we used chloroplast CAPS markers that differentiate between the two species to survey wild and weedy populations of B. rapa for the capture of B. napus chloroplasts. A total of 464 B. rapa plants belonging to 14 populations growing either in close proximity to B. napus (i.e. sympatric 1 km) were ...

Euglena chloroplasts. Scanning electron micrograph (SEM) of a dying euglena releasing its chloroplasts (cyan). Euglena is a freshwater unicellular flagellate protozoan. Chloroplasts are the site of photosynthesis, the process that synthesises carbohydrates from carbon dioxide and water using sunlight. The pigment responsible for photosynthesis, chlorophyll, is found on stacks of parallel thylakoids called grana. Magnification: x7000 when printed at 10cm wide. Specimen collected from Vietnam courtesy of Mike Allen, Plymouth Marine Laboratory. - Stock Image C036/0573

The recessive nuclear vdl (for variegated and distorted leaf) mutant of tobacco was obtained by T-DNA insertion and characterized by variegated leaves and abnormal roots and flowers. Affected leaf tissues were white and distorted, lacked palisadic cells, and contained undifferentiated plastids. The variegation was due to phenotypic, rather than genetic, instability. Genomic and cDNA clones were obtained for both the mutant and wild-type VDL alleles. Three transcripts, resulting from alternate intron splicing or polyadenylation, were found for the wild type. The transcripts potentially encode a set of proteins (53, 19, and 15 kD) sharing the same N-terminal region that contains a chloroplast transit peptide capable of importing the green fluorescent protein into chloroplasts. The predicted 53-kD product belongs to the DEAD box RNA helicase family. In the homozygous vdl mutant, T-DNA insertion resulted in accumulation of the shortest transcript and the absence of the RNA helicase-encoding ...

Cytokinins regulate broad aspects of plant growth and development, such as cell division, root and shoot growth, chloroplast development, and leaf senescence. Cytokinins are perceived by a signal transduction pathway that involves receptors, phosphotransfer proteins, and the type-B response regulators. Chloroplasts, in which photosynthesis occurs, are one of the important targets of cytokinins. However, little is known about the molecular mechanisms by which cytokinins regulate chloroplast biogenesis and the key steps that regulate their development from proplastids. By a mutant-based approach, characterization of the type-B response regulators of Arabidopsis ARR1, ARR10, and ARR12 reveals their roles in chlorophyll production, cell division, light sensitivity, and cytokinin-mediated transcription. The findings support a model in which cytokinin regulates the downstream responses through the action of a multistep phosphorelay that culminates in transcriptional regulation by ARR1, ARR10, and ...

article{aa135bad-de1f-42a7-9ee6-8b5b5a8d0011, abstract = {The relative proportion of stroma lamellae and grana end membranes was determined from electron micrographs of 58 chloroplasts from 21 different plant species. The percentage of grana end membranes varied between 1 and 21% of the total thylakoid membrane indicating a large variation in the size of grana stacks. By contrast the stroma lamellae account for 20.3 +/- 2.5 (SD)% of the total thylakoid membrane. A plot of percentage stroma lamellae against percentage of grana end membranes fits a straight line with a slope of zero showing that the proportion of stroma lamellae is independent of the size of the grana stacks. That stroma lamellae account for about 20% of the thylakoid membrane is in agreement with fragmentation and separation analysis (Gadjieva et al. Biochim. Biophys. Acta 144: 92-100, 1999). Chloroplasts from spinach, grown under high or low light, were fragmented by sonication and separated by countercurrent distribution into ...

Cytosine DNA methylation is a heritable process which plays important roles in regulating development throughout the life cycle of an organism. Although methylation of nuclear DNA has been studied extensively, little is known about the state and role of DNA methylation in chloroplast genomes, especially in marine algae. Here, we have applied an integrated approach encompassing whole-genome bisulfite sequencing, methylated DNA immunoprecipitation, gene co-expression networks and photophysiological analyses to provide evidence for the role of chloroplast DNA methylation in a marine alga, the multicellular brown alga Saccharina japonica. Although the overall methylation level was relatively low in the chloroplast genome of S. japonica, gametophytes exhibited higher methylation levels than sporophytes. Gene-specific bisulfite-cloning sequencing provided additional evidence for the methylation of key photosynthetic genes. Many of them were highly expressed in sporophytes whereas genes involved in ...

TY - JOUR. T1 - The OPR Protein MTHI1 Controls the Expression of Two Different Subunits of ATP Synthase CFo in Chlamydomonas reinhardtii. AU - Ozawa, Shin Ichiro. AU - Cavaiuolo, Marina. AU - Jarrige, Domitille. AU - Kuras, Richard. AU - Rutgers, Mark. AU - Eberhard, Stephan. AU - Drapier, Dominique. AU - Wollman, Francis André. AU - Choquet, Yves. PY - 2020/4/1. Y1 - 2020/4/1. N2 - In the green alga Chlamydomonas (Chlamydomonas reinhardtii), chloroplast gene expression is tightly regulated posttranscriptionally by gene-specific trans-acting protein factors. Here, we report the identification of the octotricopeptide repeat protein MTHI1, which is critical for the biogenesis of chloroplast ATP synthase oligomycin-sensitive chloroplast coupling factor. Unlike most trans-acting factors characterized so far in Chlamydomonas, which control the expression of a single gene, MTHI1 targets two distinct transcripts: it is required for the accumulation and translation of atpH mRNA, encoding a subunit of ...

Salinity-alkalinity stress is known to adversely affect a variety of processes in plants, thus inhibiting growth and decreasing crop yield. Polyamines protect plants against a variety of environmental stresses. However, whether exogenous spermidine increases the tolerance of tomato seedlings via effects on chloroplast antioxidant enzymes and chlorophyll metabolism is unknown. In this study, we examined the effect of exogenous spermidine on chlorophyll synthesis and degradation pathway intermediates and related enzyme activities, as well as chloroplast ultrastructure, gene expression, and antioxidants in salinity-alkalinity-stressed tomato seedlings. Salinity-alkalinity stress disrupted chlorophyll metabolism and hindered uroorphyrinogen III conversion to protoporphyrin IX. These effects were more pronounced in seedlings of cultivar Zhongza No. 9 than cultivar Jinpengchaoguan. Under salinity-alkalinity stress, exogenous spermidine alleviated decreases in the contents of total chlorophyll and chlorophyll

We have surveyed a chloroplast DNA restriction fragment length polymorphism in 745 individuals, distributed rangewide in eight allopatric natural populations of jack pine (Pinus banksiana Lamb.) and eight allopatric natural populations of lodgepole pine (Pinus contorta Dougl.). The polymorphic region of the chloroplast genome is located near duplicated psbA genes. Fourteen length variants were found in the survey, and these variants distinguished the two species qualitatively. Variant diversities were high in both species (hes = 0.43 in jack pine; hes = 0.44 in lodgepole pine). Population subdivision was weak within and among lodgepole pine subspecies and in jack pine (i.e., theta values were less than 0.05). This weak subdivision is compatible with theoretical predictions for paternally inherited markers in wind-pollinated outcrossers, as well as for polymorphisms with high length mutation rates. If these populations are at a drift-migration equilibrium, the chloroplast DNA restriction fragment ...

Kangasjärvi, Saijaliisa; Lepistö, Anna; Hannikainen, Kati; Piippo, Mirva; Luomala, Eeva-Maria; Aro, Eva-Mari; Rintamäki, Eevi (2008 ...

Studies of the biogenesis of the photosynthetic protein complexes in the unicellular green alga Chlamydomonas reinhardtii have pointed to the importance of the concerted expression of nuclear and chloroplast genomes. The accumulation of chloroplast- and nuclear-encoded subunits is concerted, most of …

Plastids are considered promising bioreactors for the production of recombinant proteins, but the knowledge of the mechanisms regulating foreign protein folding, targeting, and accumulation in these organelles is still incomplete. Here we demonstrate that a plant secretory signal peptide is able to target a plastome-encoded recombinant protein to the thylakoid membrane. The fusion protein zeolin with its native signal peptide expressed by tobacco (Nicotiana tabacum) transplastomic plants was directed into the chloroplast thylakoid membranes, whereas the zeolin mutant devoid of the signal peptide, Dzeolin, is instead accumulated in the stroma. We also show that zeolin folds in the thylakoid membrane where it accumulates as trimers able to form disulphide bonds. Disulphide bonds contribute to protein accumulation since zeolin shows a higher accumulation level with respect to stromal Dzeolin, whose folding is hampered as the protein accumulates at low amounts in a monomeric form and it is not ...

Autor: Sharbel, T. F. et al.; Genre: Zeitschriftenartikel; Im Druck veröffentlicht: 2001; Keywords: aneuploid; apomixis; Arabis holboelii; chloroplast; haplotype; polyploid|br/|Chromosome-number; rust infection; evolution; mechanisms; genetics; apomixis; pathways; plants; Titel: Recurrent polyploid origins and chloroplast phylogeography in the Arabis holboellii complex (Brassicaceae)

The green alga Chlamydomonas reinhardtii possesses a CO2 concentratingmechanism (CCM) which helps in successful acclimationto low CO2 conditions. Current models of the CCM postulate that aseries of ion transporters bring HCO3- from outside the cell to thethylakoid lumen, where the carbonic anhydrase CAH3 dehydratesaccumulated HCO3- to CO2, raising the CO2 concentration forRubisco. Previously, HCO3- transporters have been identified atboth the plasma membrane and the chloroplast envelope, butthe transporter thought to be on the thylakoid membrane hasnot been identified. Three paralogous genes (BST1, BST2, BST3)belonging to the bestrophin family have been found to be upregulatedin low CO2 conditions, and their expression is controlledby CIA5, a transcription factor that controls many CCM genes.YFP fusions demonstrate that all three proteins are located onthe thylakoid membrane, and interactome studies indicate thatthey might associate with chloroplast CCM components. A singlemutant defective in ...

Genome rearrangements influence gene order and configuration of gene clusters in all genomes. Most land plant chloroplast DNAs (cpDNAs) share a highly conserved gene content and with notable exceptions, a largely co-linear gene order. Conserved gene orders may reflect a slow intrinsic rate of neutral chromosomal rearrangements, or selective constraint. It is unknown to what extent observed changes in gene order are random or adaptive. We investigate the influence of natural selection on gene order in association with increased rate of chromosomal rearrangement. We use a novel parametric bootstrap approach to test if directional selection is responsible for the clustering of functionally related genes observed in the highly rearranged chloroplast genome of the unicellular green alga Chlamydomonas reinhardtii, relative to ancestral chloroplast genomes. Ancestral gene orders were inferred and then subjected to simulated rearrangement events under the random breakage model with varying ratios of inversions

1JN0: Crystal structure of the non-regulatory A(4 )isoform of spinach chloroplast glyceraldehyde-3-phosphate dehydrogenase complexed with NADP.

Read NADK2, an Arabidopsis Chloroplastic NAD Kinase, Plays a Vital Role in Both Chlorophyll Synthesis and Chloroplast Protection, Plant Molecular Biology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.

At the same time, I was installing at home a device combining a time-lapse movie camera and a microscope, thanks to a gift by my father. This allowed me to do my first research work. I was studying a phenomenon known since 1908 as the phototaxy of chloroplasts: the property of some algae living at the surface of ponds to orient their large unique chloroplast according to the intensity of light; if the light was too intense, the chloroplast turned inside the tubular cell to present its edge. In dark or weaker light, the chloroplast, a flat plate, exposed its larger surface. The phenomenon took a few minutes, which could be analysed by time-lapse cinematography. Using different glass filters, I could show that it was not the wavelength absorbed by the chlorophyll (red light) which regulated the orientation of the chloroplasts but indirectly some yellowish pigments absorbing the blue light. I was very proud, at the age of 21, to defend this work as a small thesis at the Faculty of Sciences of ...

S.P. Mayfield, P. Lee, P. Pettersson, J. Marìn-Navarro, A. Manuell, M. Muto, M. Tran We have developed a system for expressing recombinant proteins, including human therapeutic proteins, in the chloroplast of the eukaryotic green alga Chlamydomonas reinhardtii. Expression of therapeutic proteins in eukaryotic algae offers several advantages over more traditional protein expression systems. Algae are efficient at producing complex mammalian proteins, stable transgenic lines can be generated in a few weeks, and algal systems can be scaled to high levels for a fraction of the cost of traditional fermentation systems.. We have expressed several recombinant proteins in algae, including human monoclonal antibodies. Antibodies are complex multiprotein molecules that are difficult to express in simple expression systems and expensive to produce in mammalian cell culture. We have had good success in producing these complex proteins in algal chloroplasts. We have also expressed eukaryotic protein toxins, ...

Culture of E. gracilis using wastewater effluent will improve the economics of E. gracilis biofuel production. I am seventy-one. The photosynthetic function of its chloroplast is easily lost under stress resulting in bleached mutants, while the physiological role of their residual plastid DNAs remains unclear. Euglena gracilis is a metabolically flexible, photosynthetic, and adaptable free-living protist of considerable environmental importance and biotechnological value. Euglena are single celled organisms that belong to the genus protist. - NOAA. Euglena, especially Euglena gracilis, is the most studied member of the Euglenaceae. 23: 565-567, 1967. Characteristics of Euglena. Some Euglena species also reproduce by forming reproductive cysts. Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of dried whole cell Euglena gracilis as a novel food (NF) pursuant to Regulation (EU) ...

Floral dip is a transformation method that results in the insertion of T-DNA into the genome of unfertilized ovary cells. This thesis describes the transformation of Arabidopsis thaliana plants with T-DNA from pH7WG2,0 TROL-HA-FLAG plasmid vector. TROL is a transmembrane protein that regulates electron transport flow on the thylakoid membranes of chloroplasts. Addition of protein tags HA and FLAG to the TROL protein allows easier immunodetection analysis and enables further studies of the plant TROL protein function. In order to show the success of plant transformation with the TROL-HA-FLAG protein gene, the plants were subjected to multiple analyses such as seed selection method on growth plates with an added antibiotic, plant DNA PCR analysis and immunodetection analysis of plant leaf proteins. Due to the immunodetection analysis, I managed to confirm the localization of TROL-HA-FLAG protein in chloroplast thylakoid membranes of transformed plants. Further research could better show if ...

TY - JOUR. T1 - Effect of Tentoxin on the Activation and on the Catalytic Reaction of Reconstituted H+-Atpase From Chloroplasts. AU - Fromme, Petra. AU - Dahse, Ingo. AU - Gräber, Peter. PY - 1992/4/1. Y1 - 1992/4/1. N2 - The proton-translocating ATPase from chloroplasts, CF0F1, was isolated, purified and reconstitutedinto asolectin liposomes. The effect of the energy transfer inhibitor, tentoxin, on different functions of the enzyme was investigated. Tentoxin does not inhibit the nucleotide release during energization by a pH Δψ jump, i.e. the activation of the enzyme is not influenced. ATP synthesis driven by a pH Δψ T jump and multi-site ATP hydrolysis are completely inhibited by tentoxin, whereas uni-site ATP hydrolysis is not influenced.. AB - The proton-translocating ATPase from chloroplasts, CF0F1, was isolated, purified and reconstitutedinto asolectin liposomes. The effect of the energy transfer inhibitor, tentoxin, on different functions of the enzyme was investigated. Tentoxin ...

Read Chloroplast β chaperonins from A. thaliana function with endogenous cpn10 homologs in vitro, Plant Molecular Biology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.

Chloroplasts are a key feature of most guard cells; however, the function of these organelles in stomatal responses has been a subject of debate. This review examines evidence for and against a role of guard cell chloroplasts in stimulating stomatal opening. Controversy remains over the extent to which guard cell Calvin cycle activity contributes to stomatal regulation. However, this is only one of four possible functions of guard cell chloroplasts; other roles include supply of ATP, blue-light signalling and starch storage. Evidence exists for all these mechanisms, but is highly dependent upon species and growth/measurement conditions, with inconsistencies between different laboratories reported. Significant plasticity and extreme flexibility in guard cell osmoregulatory, signalling and sensory pathways may be one explanation. The use of chlorophyll a fluorescence analysis of individual guard cells is discussed in assessing guard and mesophyll cell physiology in relation to stomatal function. ...

Baier, M., König, J., Horling, F., and Dietz, K. - J. (2002). Detoxification of peroxides in the chloroplast: Whats the role of 2-Cys peroxiredoxins in Proceedings of the International Congress on Photosynthesis (Collingwood: CSIRO ...

Has anyone ever worked with tagetitoxin, a selective transcription inhibitor of chloroplast with arabidopsis? I would like to know who sells tagetitoxin, and at which concentrations it is recommendable to work with on Arabidopsis. I would appriciate very much any info on this subject. Diana ,http://bgumail.bgu.ac.il/agent/[email protected], leicaj at bgumail.bgu.ac.il ...

Yersinia pseudotuberculosis (see comment below) and listeriolysin O from Listeria monocytogenes) that are known to cause invasion of mammalian cells. They then inserted these genes into S. elongatus. After this, 4.8% of the mammalian cells that they exposed these S. elongatus were positively fluoresent, showing that they had been successfully invaded by the engineered version of S. elongatus.. A third experiment involving macrophages showed that, unlike E. coli, the engineered S. elongatus was able to increase its fluoresence within the host cell (for a few days at least). This means that the bacteria were growing and dividing successfully within the cell.. The work described in this paper demonstrates, in a controlled laboratory setting, the first few steps that would be required to establish an intracellular symbiosis such as the one believed to have been responsible for the first chloroplasts (which therefore enabled the evolution of plants, an oxygen atmosphere, animals, and eventually you ...

Home » Resolving the genera Aloysia and Acantholippia within the tribe Lantaneae (Verbenaceae), using chloroplast and nuclear sequence data ...

A gapped BLAST reveals four significant hits to the ATP Synthase Epsilon Chain proteins from a number of organisms. For example: Residues 4-112 are 25% similar to the AtpC of M.genitalium (ATPE_MYCGE). Residues 7-112 are 25% similar to the ATP synthase epsilon chain of Euglena gracilis chloroplast (ATPE_EUGGR). The other two significant hits were to the ATP synthase epsilon chains of M.pneumoniae (ATPE_MYCPN), and M.gallisepticum (ATPE_MYCGA). In addition to these results, one iteration of PSI-BLAST resulted in significant hits to the ATP synthase epsilon chains of a number of organisms. For example: Significant hits were made to the ATP synthase epsilon chains of: C.vulgaris chloroplasts (ATPE_CHLVU), M.polymorpha cholorplast (ATPE_MARPO), Anabaena PCC7120 (a cyanobacterium) (ATPE_ANASP) and many others ...

They are initiated by colored pigments, mainly green colored chlorophylls. ... (Dark Reaction) Does not require light Calvin Cycle Occurs in stroma of chloroplast Requires CO2 Uses ATP and NADPH as fuel to … The dark reaction occurs in the stroma of the chloroplast. On the other hand, the dark reactions always take place in the stroma of the chloroplasts. See http://www.merlot.org/merlot/viewMaterial.htm?id=481167, MERLOT description and link to Photosynthesis Interactive Animated Tutorial, which includes an overview to light and dark reactions of photosynthesis, as well as photorespiration. ; Carboxylation occurs with the help of Rubisco enzyme. In contrast, ATP formation through C 2 cycle by re-oxidation of NADH produced in glycine decarboxylase reaction is not an obligatory function, rather an input of energy is necessary to drive the C 2 cycle. Explain that the dark reactions of photosynthesis take place within the stroma. Participants should have some familiarity of plant morphology and ...

The brilliant emerald green sea slug, Elysia chlorotica, spends months living on sunlight just like plants. Its been called the photosynthesizing sea slug in the past, but how it manages to do this as well as it does is a complete mystery. In a new study appearing in theBiological Bulletin, researchers reveal that the sea slug has incorporated genes from the algae that it eats. There is no way on earth that genes from an alga should work inside an animal cell, saysSidney Pierce from the University of South Florida. And yet here, they do. They allow the animal to rely on sunshine for its nutrition. So if something happens to their food source, they have a way of not starving to death until they find more algae to eat.. Chloroplast are plant organelles that contain chlorophyll, the green photosynthetic pigment. Researchers have known since the 1970s that this sea slug steals chloroplasts from the alga Vaucheria litorea. The sea slugs embed the chloroplasts into their own digestive cells, ...

The responses of the quantum efficiencies of photosystem (PS) II and PSI measured in vivo simultaneously with estimations of the activities and activation states of NADP-malate dehydrogenase, chloroplast fructose-1,6-bisphosphatase, and ribulose-1,5-bisphosphate carboxylase were used to study the relationship between electron transport and carbon metabolism. The effects of varying irradiance and CO(2) partial pressure on the relationship between the quantum efficiencies of PSI and II, and the activity of these enzymes shows that the interrelationships vary according to the limitations placed on the system. The relationship between the quantum efficiencies of PSII and PSI was linear in most situations. In response to increasing irradiance, the activity of all three enzymes increased. In the case of NADP-malate dehydrogenase this increase was well correlated with the estimated flux of electrons through PSI and PSII. The other two enzymes showed a more complex relationship with the estimated flux of

Chloroplasts are a major advantage to doing synthetic biology in plants. They produce starch and some amino acids as well as hosting photosynthesis, all fully separated from other cellular functions going on in the rest of the cell. Synthetic biology approaches could turn them into individualised micro-factories inside plant cells, synthesising whatever compound you fancy without poisoning the cell and with almost no risk of any transgenes escaping into other plants.. Stable plastid transformation was first achieved in tobacco in 1990. Since then, chloroplast transformation has been successful in many plant species - a 2009 review by Huan-Hyan Wang et al. (JGG 36:387) contains a nice table summarizing the methods used in each species. Plastid-based biosynthesis of biopharmaceuticals has been researched for years, but synthetic biology technologies make it possible to consider moving beyond synthesis of antigens and relatively simple molecules (for examples see Daniell et al. 2009, Trends in ...

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D-loop replication is a proposed process by which circular DNA like chloroplasts and mitochondria replicate their genetic material. An important component of understanding D-loop replication is that many chloroplasts and mitochondria have a single circular chromosome like bacteria instead of the linear chromosomes found in eukaryotes. However, many chloroplasts and mitochondria have a linear chromosome, and D-loop replication is not important in these organelles. Also, not all circular genomes use D-loop replication as the process of replicating its genome. In many organisms, one strand of DNA in the plasmid comprises heavier nucleotides (relatively more purines: adenine and guanine). This strand is called the H (heavy) strand. The L (light) strand comprises lighter nucleotides (pyrimidines: thymine and cytosine). Replication begins with replication of the heavy strand starting at the D-loop (also known as the control region). A D-loop is a short portion in circular DNA that has three strands ...

CHLORORESPIRATORY REDUCTION22; Involved in multiple sites RNA editing events in chloroplasts. Involved in the editing of the site 7 of ndhB (ndhB- 7) and site 5 of ndhD (ndhD-5) transcripts, which are two plastid- encoded subunits of the chloroplast NAD(P)H dehydrogenase (NDH) complex. Involved in the editing of the site 3 of rpoB (rpoB-3) transcript. Required for the activity of the NDH complex of the photosynthetic electron transport chain. Possesses low endoribonuclease activity in vitro (809 aa ...

Im trying to find out how to describe the structure of a chromoplast for a biochemistry lab. Ive found plenty of information on chloroplasts, and I would assume their structure would be similar to that of a chromoplast, just with different pigments. However, I havent been able to find any information to back that up. Most pages simply describe the function of a chromoplast, and though Ive asked a few tutors, none of them seem to know how a chromoplast is structured ...

According to our data, the solution of water + sodium bicarbonate has caused the spinach leaves to begin respiration of photosynthesize causing them to rise in the presence of carbon dioxide. It occurs within each chloroplast in most of the green plants, and Carbon dioxide is one of the main components of this process. Figure 1 University. The main issue that was faced was when the leaf disks were being exposed to the higher percentages of sodium bicarbonate while they were being vacuumed in the syringe. This resulted in the reaction yield being 31.5%. During the reaction carbon dioxide, water is converted into glucose and oxygen as shown below: Helpful? In testing the hypothesis we use 4 test experiments 1 with soapy water as the negative control, one with Sodium bicarbonate as the positive control, one with no light, and one with warm water and light. In this lab, a spectrophotometer was used to measure the level of light transmitted in the chloroplasts of spinach leaves. Hypothesis As the ...

Title: Protein Quality Control: A to Z of the PQC. Abstract. Protein quality control, known as proteostasis, is fundamental aspect of the health of the cellular proteome. It constitutes the regulation of protein synthesis, folding, unfolding and turnover. It is mediated by chaperones and proteases along with cellular clearance mechanisms such as autophagy and lysosomal degradation. Proteostasis is an evolutionary conserved process in cells from bacteria to humans. Imbalance in proteostasis leads to protein aggregation and successful proteostasis is the detection and removal of misfolded proteins by quality control pathways. The Casein lytic proteinase/heat shock protein100 (Clp/Hsp100) proteins are ATP dependent chaperones belonging to the AAA family of proteins that act to remodel/disassemble protein complexes and/or protein aggregates. Cytosolic AtHsp101 has a unique role in acquired thermotolerance and that a chloroplast-targeted ClpB is essential for chloroplast development and seedling ...

Morphological, ultrastructural, and molecular- sequence data were used to assess the phylogenetic position of a tetraflagellate green alga isolated from soil samples of a saline dry basin near Fderick, Mauritania. This alga can grow as individual cells or form non- coenobial colonies of up to 12 individuals. It has a parietal chloroplast with an embedded pyrenoid covered by a starch sheath and traversed by single parallel thylakoids, and an eyespot located in a parietal position opposite to the flagellar insertion. Lipid vacuoles are present in the cytoplasm. Microspectroscopy indicated the presence of chlorophylls a and b, with lutein as the major carotenoid in the chloroplast, while the eyespot spectrum has a shape typical of green-algal eyespots. The cell has four flagella, two of them long and two considerably shorter. Sequence data from the 18S rRNA gene and ITS2 were obtained and compared with published sequences for green algae. Results from morphological and ultrastructural examinations ...