Plant hormones Essay -- essays research papers

im kit and caboodle horm nonp beils be specialized chemical substances produced by puts. They ar the main internal factors stopling growth and emergence. Hormones ar produced in one divulge of a plant and transported to others, where they ar effective in very(prenominal) small amounts. Depending on the bum tissue, a given hormone may have disparate effects. Plant hormones play an integral role in autocratic the growth and outgrowth of plants. A plant hormone is more often than not described as an original compound synthesized in one part of the plant and translocated to another part, where in utter concentrations elicits a physiological response. on that point are five slackly recognized classes of plant hormones some of the classes are represented by barely one compound, others by several different compounds. They are all essential compounds, they may resemble molecules which turn up elsewhere in plant structure or function, but they are not directly mixed as nutrients or metabolites.Hormone witnesserActionAuxinsapical meristem (only moves down), conceptus of seed, young leavesControl of cell extensionapical dominance (prevents askant buds) prevents abscission continued growth of result cell naval division in vascular and cork cambium--formation of lateral root from pericycle--formation of adventitious roots from cuttings Gibberellinsroot and young leavesCell (stem) elongation (works in stems and leaves, but not roots) prison-breaking seed/bud dormancy touch fruit set Cytokininsroots, embryos, fruitsactively growingPromote cell division--signal axillary/lateral bud growth--prevent leaf abscission chloroplast development breaking dormancy in some seeds enhance flowering leaven fruit development Abscissic pungent ... ...ascade ultimately resulting in modification of enzyme body process, modify metabolic processes, and different phenotypes. ace thing plant hormones specifically control is gene rumination. The exact mechanisms by which hormones regulate gene expression are poorly understood. Gene expression is part of a large working out process. This process involves repeated transcription of DNA resulting in many copies of informational RNA (1st increase step) template RNA is processed and enters the cytoplasm where it is translated many times by ribosomes into a gene fruit such as an enzyme (2nd amplification step) enzymes are modified to become utilitarian and capable of high catalytic activity even at low concentrations. They catalyze the production of many copies of an classic cellular product (3rd amplification step). It is likely that gene regulation is touch on by certain enzymes by and by initial hormone binding. Genes may be altered by second-string and tertiary messengers of a cellular go down as well. Hormones may indirectly control gene expression through and through these enzymes and messengers at a crook of control sites such as transcription, mRNA processing, mRNA stability , translation, and post-translation Plant hormones Essay -- essays research papers Plant hormones are specialized chemical substances produced by plants. They are the main internal factors controlling growth and development. Hormones are produced in one part of a plant and transported to others, where they are effective in very small amounts. Depending on the target tissue, a given hormone may have different effects. Plant hormones play an integral role in controlling the growth and development of plants. A plant hormone is generally described as an organic compound synthesized in one part of the plant and translocated to another part, where in low concentrations elicits a physiological response.There are five generally recognized classes of plant hormones some of the classes are represented by only one compound, others by several different compounds. They are all organic compounds, they may resemble molecules which turn up elsewhere in plant structure or function, b ut they are not directly involved as nutrients or metabolites.HormoneSourceActionAuxinsapical meristem (only moves down),embryo of seed, young leavesControl of cell elongationapical dominance (prevents lateral buds) prevents abscission continued growth of fruit cell division in vascular and cork cambium--formation of lateral roots from pericycle--formation of adventitious roots from cuttings GibberellinsRoots and young leavesCell (stem) elongation (works in stems and leaves, but not roots)breaking seed/bud dormancy stimulating fruit set Cytokininsroots, embryos, fruitsactively growingPromote cell division--signal axillary/lateral bud growth--prevent leaf abscission chloroplast development breaking dormancy in some seeds enhance flowering promote fruit development Abscissic Acid ... ...ascade ultimately resulting in modification of enzyme activity, altered metabolic processes, and different phenotypes.One thing plant hormones specifically control is gene expression. The exact me chanisms by which hormones regulate gene expression are poorly understood. Gene expression is part of a large amplification process. This process involves repeated transcription of DNA resulting in many copies of mRNA (1st amplification step) mRNA is processed and enters the cytoplasm where it is translated many times by ribosomes into a gene product such as an enzyme (2nd amplification step) enzymes are modified to become functional and capable of high catalytic activity even at low concentrations. They catalyze the production of many copies of an important cellular product (3rd amplification step). It is likely that gene regulation is affected by certain enzymes after initial hormone binding. Genes may be altered by secondary and tertiary messengers of a cellular cascade as well. Hormones may indirectly control gene expression through these enzymes and messengers at a number of control sites such as transcription, mRNA processing, mRNA stability, translation, and post-translation