Elucidating molecular mechanisms by which seeds respond to environmental factors

阐明种子响应环境因素的分子机制

• 批准号: RGPIN-2014-03621
• 负责人: Nambara, Eiji
• 金额: $ 2.48万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=587316
• 关键词: Elucidating; molecular; mechanisms; seeds; respond

Plant hormones are low abundant signal molecules, which significantly influence a variety of processes in plant growth and development. Functional genomics research in cereals has revealed that key genetic loci for yield production and stress responses selected by the classical breeding include a series of hormone metabolism and signaling genes. The plant hormone metabolism is regulated by a number of environmental factors and plays an important role in tuning plant growth in response to changing environment. Current challenge in plant biology and biotechnology is to understand how plants sense the environmental factors and alter the plant hormone metabolism. The Nambara research group studies how plants control cellular concentrations of the plant hormone levels with a focus on abscisic acid (ABA) metabolism. We use Arabidopsis seed germination as a model system, because seeds have sophisticated mechanisms to sense environmental conditions. Mature, dry seeds contain all the components required to resume the plant’s life cycle in an appropriate environment. The seeds sense water, nutrients, temperature, after-ripening, and light to determine if the appropriate germination environment exists, and a change in these external cues alters plant hormone metabolism and signaling, which determine whether seeds germinate or remain dormant. The proposed research aims to elucidate the molecular mechanisms by which seeds sense environmental signals and regulate plant hormone metabolism, with a focus on how nitrate regulates ABA catabolism and seed germination. Nitrate is a major nitrogen source existing in soil and influences plant growth and development as a nutrient and as a signal. As a nutrient, nitrate is assimilated to ammonium and then incorporated into amino acids. As a signal, low nitrate concentration causes rapid reprogramming of genome-wide gene expression, even in mutants defective in nitrate assimilation. Nitrate promotes seed germination in many plant species. The effect of nitrate on germination can be observed in mutants defective in nitrate assimilation. This indicates that it acts as a signal to stimulate germination. My research group previously reported that nitrate activates ABA catabolism and reduces ABA, an inhibitor of germination. Despite recent identification of essential genes for nitrate sensing and signal transduction, the molecular mechanisms by which nitrate regulates ABA catabolism remain largely unknown. The overall goal of this grant is to investigate the molecular and cellular mechanisms involved in nitrate regulation of ABA metabolism and seed germination. My research group has recently identified the novel factor regulating these processes during Arabidopsis seed germination. We will elucidate the molecular function of the regulators in nitrate signaling in seeds. Stable crop yield under nitrate limited condition is a key target for plant biotechnology, because sustainable agricultural practices must limit expensive and potentially polluting nitrate inputs. Our basic research will help to gain a novel solution to increase crop yield and decrease crop losses.

植物激素是丰富的信号分子，在谷物中，过程在植物生长和发育中的显着影响激素代谢是由许多环境因素和发挥作用以及在E当前的环境中调整植物的重要作用。植物激素水平的控制浓度以脱落（ABA）的代谢为重点，我们使用拟南芥种子发芽，因为ASEED具有复杂的机制，以使其成熟。适当的环境水，蛋白质，成熟后的光，确定适当的发芽环境是否改变了植物激素的代谢和信号传导，这确定种子是否会发芽或保持休眠状态。 。 硝酸盐是土壤中存在的主要氮，会影响植物的生长和发育，尽可能高达一定程度高达铵，并掺入氨基酸为氨基酸时，硝酸盐浓度较低。基因组的基因表达，硝酸盐同化。发芽。 分子和细胞机制的整体涉及Inva代谢和种子种子。是植物生物技术的关键目标。