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.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.Plant Root Cap: A cone-shaped structure in plants made up of a mass of meristematic cells that covers and protects the tip of a growing root. It is the putative site of gravity sensing in plant roots.Genes, Plant: The functional hereditary units of PLANTS.Plant Roots: The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.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)Gravitropism: The directional growth of organisms in response to gravity. In plants, the main root is positively gravitropic (growing downwards) and a main stem is negatively gravitropic (growing upwards), irrespective of the positions in which they are placed. Plant gravitropism is thought to be controlled by auxin (AUXINS), a plant growth substance. (From Concise Dictionary of Biology, 1990)Zein: A group of alcohol-soluble seed storage proteins from the endosperm of corn.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.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.Plant Shoots: New immature growth of a plant including stem, leaves, tips of branches, and SEEDLINGS.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.Indoleacetic Acids: Acetic acid derivatives of the heterocyclic compound indole. (Merck Index, 11th ed)Pyruvate, Orthophosphate Dikinase: An enzyme that catalyzes the reaction of ATP, pyruvate, and orthophosphate to form AMP plus phosphoenolpyruvate plus pyrophosphate. EC 18.104.22.168.Chromosomes, Plant: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.Zearalenone: (S-(E))-3,4,5,6,8,10-Hexahydro-14,16-dihydroxy-3-methyl-1H-2-benzoxacyclotetradecin-1,7(8H)-dione. One of a group of compounds known under the general designation of resorcylic acid lactones. Cis, trans, dextro and levo forms have been isolated from the fungus Gibberella zeae (formerly Fusarium graminearum). They have estrogenic activity, cause toxicity in livestock as feed contaminant, and have been used as anabolic or estrogen substitutes.Endosperm: Nutritive tissue of the seeds of flowering plants that surrounds the EMBRYOS. It is produced by a parallel process of fertilization in which a second male gamete from the pollen grain fuses with two female nuclei within the embryo sac. The endosperm varies in ploidy and contains reserves of starch, oils, and proteins, making it an important source of human nutrition.RNA, Plant: Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.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.Pollen: The fertilizing element of plants that contains the male GAMETOPHYTES.Crops, Agricultural: Cultivated plants or agricultural produce such as grain, vegetables, or fruit. (From American Heritage Dictionary, 1982)Seedling: Very young plant after GERMINATION of SEEDS.Plant Growth Regulators: Any of the hormones produced naturally in plants and active in controlling growth and other functions. There are three primary classes: auxins, cytokinins, and gibberellins.Cotyledon: A part of the embryo in a seed plant. The number of cotyledons is an important feature in classifying plants. In seeds without an endosperm, they store food which is used in germination. In some plants, they emerge above the soil surface and become the first photosynthetic leaves. (From Concise Dictionary of Biology, 1990)Anthocyanins: A group of FLAVONOIDS derived from FLAVONOLS, which lack the ketone oxygen at the 4-position. They are glycosylated versions of cyanidin, pelargonidin or delphinidin. The conjugated bonds result in blue, red, and purple colors in flowers of plants.Gravity Sensing: Process whereby a cell, bodily structure, or organism (animal or plant) receives or detects a gravity stimulus. Gravity sensing plays an important role in the directional growth and development of an organism (GRAVITROPISM).Soil: The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land 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.Oryza sativa: Annual cereal grass of the family POACEAE and its edible starchy grain, rice, which is the staple food of roughly one-half of the world's population.Inbreeding: The mating of plants or non-human animals which are closely related genetically.Poaceae: A large family of narrow-leaved herbaceous grasses of the order Cyperales, subclass Commelinidae, class Liliopsida (monocotyledons). Food grains (EDIBLE GRAIN) come from members of this family. RHINITIS, ALLERGIC, SEASONAL can be induced by POLLEN of many of the grasses.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Abscisic Acid: Abscission-accelerating plant growth substance isolated from young cotton fruit, leaves of sycamore, birch, and other plants, and from potatoes, lemons, avocados, and other fruits.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.Humic Substances: Organic matter in a state of advanced decay, after passing through the stages of COMPOST and PEAT and before becoming lignite (COAL). It is composed of a heterogenous mixture of compounds including phenolic radicals and acids that polymerize and are not easily separated nor analyzed. (E.A. Ghabbour & G. Davies, eds. Humic Substances, 2001).Phthalimides: The imide of phthalic acids.Gravitation: Acceleration produced by the mutual attraction of two masses, and of magnitude inversely proportional to the square of the distance between the two centers of mass. It is also the force imparted by the earth, moon, or a planet to an object near its surface. (From NASA Thesaurus, 1988)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 Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.Herbicides: Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE.
Southern corn leaf blight: Southern corn leaf blight (SCLB) is a fungal disease of maize caused by the plant pathogen Bipolaris maydis (also known as Cochliobolus heterostrophus in its teleomorph state).Mucigel: Mucigel is a slimy substance that covers the root cap of the roots of plants. It is a highly hydrated polysaccharide, most likely a pectin, which is secreted from the outermost (epidermal) cells of the rootcap.Endodermis: The endodermis is the central, innermost layer of cortex in some land plants. It is made of compact living cells surrounded by an outer ring of endodermal cells that are impregnated with hydrophobic substances (Casparian Strip) to restrict apoplastic flow of water to the inside.Squamosa promoter binding protein: The SQUAMOSA promoter binding protein-like (SBP or SPL) family of transcription factors are defined by a plant-specific DNA-binding domain. The founding member of the family was identified based on its specific in vitro binding to the promoter of the snapdragon SQUAMOSA gene.Tomato seed oil: Tomato seed oil is a vegetable oil extracted from the seeds of tomatoes.Canna Leaf Roller: Cannas are largely free of pests, but in the USA plants sometimes fall victim the Canna Leaf Roller, which can actually be two different insects. Larva of the Brazilian skipper butterfly (Calpodes ethlius), also known as the Larger Canna Leaf Roller, cut the leaves and roll them over to live inside while pupating and eating the leaf.Zein: Zein is a class of prolamine protein found in maize (corn). It is usually manufactured as a powder from corn gluten meal.Coles PhillipsAuxin binding protein: In molecular biology, the auxin binding protein family is a family of proteins which bind auxin. They are located in the lumen of the endoplasmic reticulum (ER).Dikinase: Dikinases are a category of enzymes that catalyze the chemical reactionTriacetic acid lactonePlant perception (physiology): Plant perception is the ability of plants to sense and respond to the environment to adjust their morphology, physiology and phenotype accordingly. Other disciplines such as plant physiology, ecology and molecular biology are used to assess this ability.PollenPlant breeders' rights: Plant breeders' rights (PBR), also known as plant variety rights (PVR), are rights granted to the breeder of a new variety of plant that give the breeder exclusive control over the propagating material (including seed, cuttings, divisions, tissue culture) and harvested material (cut flowers, fruit, foliage) of a new variety for a number of years.Chance seedling: A chance seedling is a plant that is the product of unintentional breeding. It may be a genetically unique individual with desirable characteristics that is then intentionally bred.Placental cotyledon: In human development, the cotyledons are the approximately 15-25 separations of the decidua basalis of the placenta, separated by placental septa.Page 565 in: Each cotyledon consists of a main stem of a chorionic villus] as well as its branches and subbranches etc.Anthocyanin 5-O-glucosyltransferase: Anthocyanin 5-O-glucosyltransferase is an enzyme that forms anthocyanin 3,5-O-diglucoside from anthocyanin 3-O-glucoside.AmyloplastIndex of soil-related articles: This is an index of articles relating to soil.Protein primary structure: The primary structure of a peptide or protein is the linear sequence of its amino acid structural units, and partly comprises its overall biomolecular structure. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end.Weedy rice: Weedy rice, also known as red rice, is a variety of rice (Oryza) that produces far fewer grains per plant than cultivated rice and is therefore considered a pest. The name "weedy rice" is used for all types and variations of rice which show some characteristic features of cultivated rice and grow as weeds in commercial rice fields.Inbreeding depression: Inbreeding depression is the reduced biological fitness in a given population as a result of inbreeding, or breeding of related individuals. Population biological fitness refers to its ability to survive and reproduce itself.Paddock: A paddock has two primary meanings in different parts of the English-speaking world. In Canada, the USA and UK, a paddock is a small enclosure used to keep horses.Branching order of bacterial phyla (Gupta, 2001): There are several models of the Branching order of bacterial phyla, one of these was proposed in 2001 by Gupta based on conserved indels or protein, termed "protein signatures", an alternative approach to molecular phylogeny. Some problematic exceptions and conflicts are present to these conserved indels, however, they are in agreement with several groupings of classes and phyla.Symmetry element: A symmetry element is a point of reference about which symmetry operations can take place. In particular, symmetry elements can be centers of inversion, axes of rotation and mirror planes.Phaseic acidStarch gelatinization: Starch gelatinization is a process of breaking down the intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites (the hydroxyl hydrogen and oxygen) to engage more water. This irreversibly dissolves the starch granule in water.Humic acid: Humic acid is a principal component of humic substances, which are the major organic constituents of soil (humus), peat and coal. It is also a major organic constituent of many upland streams, dystrophic lakes, and ocean water.PomalidomideFujiyama (roller coaster)LeucoplastComposite transposon: A composite transposon is similar in function to simple transposons and Insertion Sequence (IS) elements in that it has protein coding DNA segments flanked by inverted, repeated sequences that can be recognized by transposase enzymes. A composite transposon, however, is flanked by two separate IS elements which may or may not be exact replicas.Herbicide: Herbicide(s), also commonly known as weedkillers, are pesticides used to control unwanted plants. Selective herbicides control specific weed species, while leaving the desired crop relatively unharmed.
(1/5543) Cloning and characterization of a maize cytochrome-b5 reductase with Fe3+-chelate reduction capability.
We previously purified an NADH-dependent Fe3+-chelate reductase (NFR) from maize roots with biochemical features of a cytochrome-b5 reductase (b5R) [Sparla, Bagnaresi, Scagliarini and Trost (1997) FEBS Lett. 414, 571-575]. We have now cloned a maize root cDNA that, on the basis of sequence information, calculated parameters and functional assay, codes for NFR. Maize NFR has 66% and 65% similarity to mammal and yeast b5R respectively. It has a deduced molecular mass of 31.17 kDa and a pI of 8.53. An uncharged region is observed at its N-terminus but no myristoylation consensus site is present. Taken together, these results, coupled with previous biochemical evidence, prove that NFR belongs to the b5R class and document b5R from a plant at the molecular level for the first time. We have also identified a putative Arabidopsis thaliana NFR gene. Its organization (nine exons) closely resembles mammalian b5Rs. Several NFR isoforms are expected to exist in maize. They are probably not produced by alternative translational mechanisms as occur in mammals, because of specific constraints observed in the maize NFR cDNA sequence. In contrast with yeast and mammals, tissue-specific and various subcellular localizations of maize b5R isoforms could result from differential expression of the various members of a multigene family. The first molecular characterization of a plant b5R indicates an overall remarkable evolutionary conservation for these versatile reductase systems. In addition, the well-characterized Fe3+-chelate reduction capabilities of NFR, in addition to known Fe3+-haemoglobin reduction roles for mammal b5R isoforms, suggest further and more generalized roles for the b5R class in endocellular iron reduction. (+info)
(2/5543) Gibberellic acid stabilises microtubules in maize suspension cells to cold and stimulates acetylation of alpha-tubulin.
Gibberellic acid is known to stabilise microtubules in plant organs against depolymerisation. We have now devised a simplified cell system for studying this. Pretreatment of a maize cell suspension with gibberellic acid for just 3 h stabilised protoplast microtubules against depolymerisation on ice. In other eukaryotes, acetylation of alpha-tubulin is known to correlate with microtubule stabilisation but this is not established in plants. By isolating the polymeric tubulin fraction from maize cytoskeletons and immunoblotting with the antibody 6-11B-1, we have demonstrated that gibberellic acid stimulates the acetylation of alpha-tubulin. This is the first demonstrated link between microtubule stabilisation and tubulin acetylation in higher plants. (+info)
(3/5543) Patterns of evolutionary rate variation among genes of the anthocyanin biosynthetic pathway.
The anthocyanin biosynthetic pathway is responsible for the production of anthocyanin pigments in plant tissues and shares a number of enzymes with other biochemical pathways. The six core structural genes of this pathway have been cloned and characterized in two taxonomically diverse plant species (maize and snapdragon). We have recently cloned these genes for a third species, the common morning glory, Ipomoea purpurea. This additional information provides an opportunity to examine patterns of evolution among genes within a single biochemical pathway. We report here that upstream genes in the anthocyanin pathway have evolved substantially more slowly than downstream genes and suggest that this difference in evolutionary rates may be explained by upstream genes being more constrained because they participate in several different biochemical pathways. In addition, regulatory genes associated with the anthocyanin pathway tend to evolve more rapidly than the structural genes they regulate, suggesting that adaptive evolution of flower color may be mediated more by regulatory than by structural genes. Finally, for individual anthocyanin genes, we found an absence of rate heterogeneity among three major angiosperm lineages. This rate constancy contrasts with an accelerated rate of evolution of three CHS-like genes in the Ipomoea lineage, indicating that these three genes have diverged without coordinated adjustment by other pathway genes. (+info)
(4/5543) Inhibition of plant-pathogenic fungi by a corn trypsin inhibitor overexpressed in Escherichia coli.
The cDNA of a 14-kDa trypsin inhibitor (TI) from corn was subcloned into an Escherichia coli overexpression vector. The overexpressed TI was purified based on its insolubility in urea and then refolded into the active form in vitro. This recombinant TI inhibited both conidium germination and hyphal growth of all nine plant pathogenic fungi studied, including Aspergillus flavus, Aspergillus parasiticus, and Fusarium moniliforme. The calculated 50% inhibitory concentration of TI for conidium germination ranged from 70 to more than 300 microgram/ml, and that for fungal growth ranged from 33 to 124 microgram/ml depending on the fungal species. It also inhibited A. flavus and F. moniliforme simultaneously when they were tested together. The results suggest that the corn 14-kDa TI may function in host resistance against a variety of fungal pathogens of crops. (+info)
(5/5543) Natural occurrence of the C series of fumonisins in moldy corn.
We analyzed 44 moldy corn samples for the B and C series of fumonisins by high-performance liquid chromatography. Of the 44 samples, 32 (73%) were contaminated with both the B and C series of fumonisins and 6 were contaminated with only the B series of fumonisins. The incidence of fumonisin C1 in moldy corn was 71%; the incidence was 11% for fumonisin C3 and 43% for fumonisin C4. Their mean levels ranged from 500 to 1,900 ng/g. This is the first report on the natural occurrence of the C series of fumonisins and fumonisin B4 in moldy corn. (+info)
(6/5543) Relationship between ruminal starch degradation and the physical characteristics of corn grain.
The objectives of this study were to determine the range of variation in the rate and extent of in situ ruminal starch degradation of 14 corns differing in vitreousness and to predict ruminal starch degradability by physical characteristics of corn grains. This study was conducted with eight dent and six flint corns. Ruminal starch degradability was determined by an in situ technique on 3-mm ground grains. Physical characteristics of corn grain were measured: hardness by grinding energy and particle size distribution, apparent and true densities, and specific surface area. Ruminal DM and starch degradabilities averaged 50 and 55.1% and varied from 39.7 to 71.5% and from 40.6 to 77.6%, respectively. Ruminal starch degradability averaged 61.9 and 46.2% in dent and flint types, respectively. The proportion of coarse particles (61.9 vs. 69.6% for dent and flint, respectively), the apparent density (1.29 vs. 1.36 g/cm3 for dent and flint, respectively), and the specific surface area (.13 vs. .07 m2/g for dent and flint, respectively) varied with the vitreousness. Ruminal starch degradability could be predicted accurately by vitreousness (r2 = .89) or by the combination of apparent density and 1,000-grain weight (R2 = .91), a measurement faster than the vitreousness determination. (+info)
(7/5543) Growth phase-dependent subcellular localization of nitric oxide synthase in maize cells.
A protein band of approximately 166 kDa was detected in the soluble fraction of root tips and young leaves of maize seedlings, based on Western blot analysis using antibodies raised against mouse macrophage nitric oxide synthase (NOS) and rabbit brain NOS. NOS activity was present in these soluble fractions, as determined by L-[U-14C]citrulline synthesis from L[U-14]arginine. Immunofluorescence showed that the maize NOS protein is present in the cytosol of cells in the division zone and is translocated into the nucleus in cells in the elongation zone of maize root tips. These results indicate the existence of a NOS enzyme in maize tissues, with the localization of this protein depending on the phase of cell growth. (+info)
(8/5543) Characterization of maize (Zea mays L.) Wee1 and its activity in developing endosperm.
We report the characterization of a maize Wee1 homologue and its expression in developing endosperm. Using a 0.8-kb cDNA from an expressed sequence tag project, we isolated a 1.6-kb cDNA (ZmWee1), which encodes a protein of 403 aa with a calculated molecular size of 45.6 kDa. The deduced amino acid sequence shows 50% identity to the protein kinase domain of human Wee1. Overexpression of ZmWee1 in Schizosaccharomyces pombe inhibited cell division and caused the cells to enlarge significantly. Recombinant ZmWee1 obtained from Escherichia coli is able to inhibit the activity of p13(suc1)-adsorbed cyclin-dependent kinase from maize. ZmWee1 is encoded by a single gene at a locus on the long arm of chromosome 4. RNA gel blots showed the ZmWee1 transcript is about 2.4 kb in length and that its abundance reaches a maximum 15 days after pollination in endosperm tissue. High levels of expression of ZmWee1 at this stage of endosperm development imply that ZmWee1 plays a role in endoreduplication. Our results show that control of cyclin-dependent kinase activity by Wee1 is conserved among eukaryotes, from fungi to animals and plants. (+info)