Agamous protein arabidopsis. Medical search

AGAMOUS Protein, Arabidopsis: A plant homeotic protein involved in the development of stamens and carpels of Arabidopsis thaliana. It is a DNA-binding protein that contains the MADS-box domain. It is one of the four founder proteins that structurally define the superfamily of MADS DOMAIN PROTEINS.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.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.Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.MADS Domain Proteins: A superfamily of proteins that share a highly conserved MADS domain sequence motif. The term MADS refers to the first four members which were MCM1 PROTEIN; AGAMOUS 1 PROTEIN; DEFICIENS PROTEIN; and SERUM RESPONSE FACTOR. Many MADS domain proteins have been found in species from all eukaryotic kingdoms. They play an important role in development, especially in plants where they have an important role in flower development.Flowers: The reproductive organs of plants.Genes, Plant: The functional hereditary units of PLANTS.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Meristem: A group of plant cells that are capable of dividing infinitely and whose main function is the production of new growth at the growing tip of a root or stem. (From Concise Dictionary of Biology, 1990)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.RNA, Plant: Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material 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)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.Plant Structures: The parts of plants, including SEEDS.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)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.Plant Shoots: New immature growth of a plant including stem, leaves, tips of branches, and SEEDLINGS.Seedling: Very young plant after GERMINATION of SEEDS.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.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.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.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Indoleacetic Acids: Acetic acid derivatives of the heterocyclic compound indole. (Merck Index, 11th ed)Genes, Homeobox: Genes that encode highly conserved TRANSCRIPTION FACTORS that control positional identity of cells (BODY PATTERNING) and MORPHOGENESIS throughout development. Their sequences contain a 180 nucleotide sequence designated the homeobox, so called because mutations of these genes often results in homeotic transformations, in which one body structure replaces another. The proteins encoded by homeobox genes are called HOMEODOMAIN PROTEINS.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.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.Cyclamen: A plant genus of the family PRIMULACEAE that contains triterpenoid saponins.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.Germination: The initial stages of the growth of SEEDS into a SEEDLINGS. The embryonic shoot (plumule) and embryonic PLANT ROOTS (radicle) emerge and grow upwards and downwards respectively. Food reserves for germination come from endosperm tissue within the seed and/or from the seed leaves (COTYLEDON). (Concise Dictionary of Biology, 1990)Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Microscopy, Electron, Scanning: Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.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.Plant Epidermis: A thin layer of cells forming the outer integument of seed plants and ferns. (Random House Unabridged Dictionary, 2d ed)Trichomes: Hair-like extensions on specialized epidermal surfaces of plants which protect against damage from insects, animals, light degradation and fungal infection. Trichomes may also occur on certain unicellular EUKARYOTES.Homeodomain Proteins: Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).Ethylenes: Derivatives of ethylene, a simple organic gas of biological origin with many industrial and biological use.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.Oxylipins: Eighteen-carbon cyclopentyl polyunsaturated fatty acids derived from ALPHA-LINOLENIC ACID via an oxidative pathway analogous to the EICOSANOIDS in animals. Biosynthesis is inhibited by SALICYLATES. A key member, jasmonic acid of PLANTS, plays a similar role to ARACHIDONIC ACID in animals.Salicylic Acid: A compound obtained from the bark of the white willow and wintergreen leaves. It has bacteriostatic, fungicidal, and keratolytic actions.Plant Diseases: Diseases of plants.Cyclopentanes: A group of alicyclic hydrocarbons with the general formula R-C5H9.Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.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)Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Genetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.Mutagenesis, Insertional: Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.Cytokinins: Plant hormones that promote the separation of daughter cells after mitotic division of a parent cell. Frequently they are purine derivatives.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.Pseudomonas syringae: A species of gram-negative, fluorescent, phytopathogenic bacteria in the genus PSEUDOMONAS. It is differentiated into approximately 50 pathovars with different plant pathogenicities and host specificities.Plant Stomata: Closable openings in the epidermis of plants on the underside of leaves. They allow the exchange of gases between the internal tissues of the plant and the outside atmosphere.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.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.Plant Stems: Parts of plants that usually grow vertically upwards towards the light and support the leaves, buds, and reproductive structures. (From Concise Dictionary of Biology, 1990)Gibberellins: A class of plant growth hormone isolated from cultures of Gibberella fujikuroi, a fungus causing Bakanae disease in rice. There are many different members of the family as well as mixtures of multiple members; all are diterpenoid acids based on the gibberellane skeleton.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.Glucosinolates: Substituted thioglucosides. They are found in rapeseed (Brassica campestris) products and related cruciferae. They are metabolized to a variety of toxic products which are most likely the cause of hepatocytic necrosis in animals and humans.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Pollen: The fertilizing element of plants that contains the male GAMETOPHYTES.Morphogenesis: The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.Phytochrome: A blue-green biliprotein widely distributed in the plant kingdom.Brassicaceae: A plant family of the order Capparales, subclass Dilleniidae, class Magnoliopsida. They are mostly herbaceous plants with peppery-flavored leaves, due to gluconapin (GLUCOSINOLATES) and its hydrolysis product butenylisotrhiocyanate. The family includes many plants of economic importance that have been extensively altered and domesticated by humans. Flowers have 4 petals. Podlike fruits contain a number of seeds. Cress is a general term used for many in the Brassicacea family. Rockcress is usually ARABIS; Bittercress is usually CARDAMINE; Yellowcress is usually RORIPPA; Pennycress is usually THLASPI; Watercress refers to NASTURTIUM; or RORIPPA or TROPAEOLUM; Gardencress refers to LEPIDIUM; Indiancress refers to TROPAEOLUM.Chromosomes, Plant: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.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.Glucuronidase Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.

HUA1 and HUA2 are two members of the floral homeotic AGAMOUS pathway. (1/85)

The identities of the four floral organ types in an Arabidopsis flower are specified by the combinatorial activities of the floral homeotic A, B, and C function genes; AGAMOUS is the only known C function gene. We have identified two genes that interact with AG in the specification of floral structure, HUA1 and HUA2, from a screen for enhancers of a weak ag allele, ag-4. HUA1 and HUA2 are involved in all aspects of AG function. HUA2 encodes a novel protein that contains nuclear localization signals and signature motifs that suggest HUA2, like AG, may be a transcription factor. Molecular analyses suggest that HUA2 (and possibly HUA1) acts to facilitate AG action at the same hierarchical level as AG. (+info)

CRABS CLAW and SPATULA, two Arabidopsis genes that control carpel development in parallel with AGAMOUS. (2/85)

To help understand the process of carpel morphogenesis, the roles of three carpel development genes have been partitioned genetically. Mutants of CRABS CLAW cause the gynoecium to develop into a wider but shorter structure, and the two carpels are unfused at the apex. Mutants of a second gene, SPATULA, show reduced growth of the style, stigma, and septum, and the transmitting tract is absent. Double mutants of crabs claw and spatula with homeotic mutants that develop ectopic carpels demonstrate that CRABS CLAW and SPATULA are necessary for, and inseparable from, carpel development, and that their action is negatively regulated by A and B organ identity genes. The third carpel gene studied, AGAMOUS, encodes C function that has been proposed to fully specify carpel identity. When AGAMOUS function is removed together with the A class gene APETALA2, however, the organs retain many carpelloid properties, suggesting that other genes are also involved. We show here that further mutant disruption of both CRABS CLAW and SPATULA function removes remaining carpelloid properties, revealing that the three genes together are necessary to generate the mature gynoecium. In particular, AGAMOUS is required to specify the identity of the carpel wall and to promote the stylar outgrowth at the apex, CRABS CLAW suppresses radial growth of the developing gynoecium but promotes its longitudinal growth, and SPATULA supports development of the carpel margins and tissues derived from them. The three genes mostly act independently, although there is genetic evidence that CRABS CLAW enhances AGAMOUS and SPATULA function. (+info)

The Arabidopsis FILAMENTOUS FLOWER gene is required for flower formation. (3/85)

A screen for mutations affecting flower formation was carried out and several filamentous flower (fil) alleles were identified. In fil mutants, floral primordia occasionally give rise to pedicels lacking flowers at their ends. This defect is dramatically enhanced in fil rev double mutants, in which every floral primordium produces a flowerless pedicel. These data suggest that the FIL and REV genes are required for an early step of flower formation, possibly for the establishment of a flower-forming domain within the floral primordium. The FIL gene is also required for establishment of floral meristem identity and for flower development. During flower development, the FIL gene is required for floral organ formation in terms of the correct numbers and positions; correct spatial activity of the AGAMOUS, APETALA3, PISTILLATA and SUPERMAN genes; and floral organ development. (+info)

Activation of a floral homeotic gene in Arabidopsis. (4/85)

The patterned expression of floral homeotic genes in Arabidopsis depends on the earlier action of meristem-identity genes such as LEAFY, which encodes a transcription factor that determines whether a meristem will generate flowers instead of leaves and shoots. The LEAFY protein, which is expressed throughout the flower, participates in the activation of homeotic genes, which are expressed in specific regions of the flower. Analysis of a LEAFY-responsive enhancer in the homeotic gene AGAMOUS indicates that direct interaction of LEAFY with this enhancer is required for its activity in plants. Thus, LEAFY is a direct upstream regulator of floral homeotic genes. (+info)

Non-AUG initiation of AGAMOUS mRNA translation in Arabidopsis thaliana. (5/85)

The MADS box organ identity gene AGAMOUS (AG) controls several steps during Arabidopsis thaliana flower development. AG cDNA contains an open reading frame that lacks an ATG triplet to function as the translation initiation codon, and the actual amino terminus of the AG protein remains uncharacterized. We have considered the possibility that AG translation can be initiated at a non-AUG codon. Two possible non-AUG initiation codons, CUG and ACG, are present in the 5' region of AG mRNA preceding the highly conserved MADS box sequence. We prepared a series of AG genomic constructs in which these codons are mutated and assayed their activity in phenotypic rescue experiments by introducing them as transgenes into ag mutant plants. Alteration of the CTG codon to render it unsuitable for acting as a translation initiation site does not affect complementation of the ag-3 mutation in transgenic plants. However, a similar mutation of the downstream ACG codon prevents the rescue of the ag-3 mutant phenotype. Conversely, if an ATG is introduced immediately 5' to the disrupted ACG codon, the resulting construct fully complements the ag-3 mutation. The AG protein synthesized in vitro by initiating translation at the ACG position is active in DNA binding and is of the same size as the AG protein detected from floral tissues, whereas AG polypeptides with additional amino-terminal residues do not appear to bind DNA. These results indicate that translation of AG is initiated exclusively at an ACG codon and prove that non-AUG triplets may be efficiently used as the sole translation initiation site in some plant cellular mRNAs. (+info)

Redundant enhancers mediate transcriptional repression of AGAMOUS by APETALA2. (6/85)

The floral homeotic gene AGAMOUS specifies stamen and carpel fate in the central whorls of Arabidopsis flowers. Transcription of AGAMOUS RNA is restricted to the center of developing flowers by several, partially redundant negative regulators, one of which is the homeotic gene APETALA2. We have identified regulatory elements that mediate transcriptional repression of AGAMOUS by APETALA2 and found that several redundant elements respond independently to loss of APETALA2 activity. Thus, redundancy at the level of cis-regulatory sequences is independent of redundancy at the level of trans-regulators. We have also found that only the early, but not the late, effects of APETALA2 on AGAMOUS require the meristem-identity protein LEAFY, a positive regulator of AGAMOUS. (+info)

Ectopic hypermethylation of flower-specific genes in Arabidopsis. (7/85)

BACKGROUND: Arabidopsis mutations causing genome-wide hypomethylation are viable but display a number of specific developmental abnormalities, including some that resemble known floral homeotic mutations. We previously showed that one of the developmental abnormalities present in an antisense-METHYLTRANSFERASEI (METI) transgenic line resulted from ectopic hypermethylation of the SUPERMAN gene. RESULTS: Here, we investigate the extent to which hypermethylation of SUPERMAN occurs in several hypomethylation mutants, and describe methylation effects at a second gene, AGAMOUS. SUPERMAN gene hypermethylation occurred at a high frequency in several mutants that cause overall decreases in genomic DNA methylation. The hypermethylation pattern was largely similar in the different mutant backgrounds. Genetic analysis suggests that hypermethylation most likely arose either during meiosis or somatically in small sectors of the plant. A second floral development gene, AGAMOUS, also became hypermethylated and silenced in an Arabidopsis antisense-METI line. CONCLUSIONS: These results suggest that ectopic hypermethylation of specific genes in mutant backgrounds that show overall decreases in methylation may be a widespread phenomenon that could explain many of the developmental defects seen in Arabidopsis methylation mutants. This resembles a phenomenon seen in cancer cells, which can simultaneously show genome-wide hypomethylation and hypermethylation of specific genes. Comparison of the methylated sequences in SUPERMAN and AGAMOUS suggests that hypermethylation could involve DNA secondary structures formed by pyrimidine-rich sequences. (+info)

Specific and heritable genetic interference by double-stranded RNA in Arabidopsis thaliana. (8/85)

We investigated the potential of double-stranded RNA interference (RNAi) with gene activity in Arabidopsis thaliana. To construct transformation vectors that produce RNAs capable of duplex formation, gene-specific sequences in the sense and antisense orientations were linked and placed under the control of a strong viral promoter. When introduced into the genome of A. thaliana by Agrobacterium-mediated transformation, double-stranded RNA-expressing constructs corresponding to four genes, AGAMOUS (AG), CLAVATA3, APETALA1, and PERIANTHIA, caused specific and heritable genetic interference. The severity of phenotypes varied between transgenic lines. In situ hybridization revealed a correlation between a declining AG mRNA accumulation and increasingly severe phenotypes in AG (RNAi) mutants, suggesting that endogenous mRNA is the target of double-stranded RNA-mediated genetic interference. The ability to generate stably heritable RNAi and the resultant specific phenotypes allows us to selectively reduce gene function in A. thaliana. (+info)