L-Ser代谢的遗传操作及其影响植物生长发育的分子机制研究

项目名称： L-Ser代谢的遗传操作及其影响植物生长发育的分子机制研究

项目编号： No.31270296

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 生物科学

项目作者： 王勇

作者单位： 南开大学

项目金额： 80万元

中文摘要： L-Ser是植物赖以生存的基本氨基酸，植物能够自己合成以满足各种代谢需要；然而L-Ser含量的升高也会导致主根生长受阻，同时促进侧根发育，引起叶片衰老、死亡，而且可能还与植物的抗性相关。很显然，内源L-Ser水平的调控对于植物的正常生长发育和其对环境条件变化的适应非常必要,相关机制的研究也因此具有重要的科学意义。本研究针对拟南芥中L-Ser代谢相关的重要酶SHMT4、SHMT5、SGAT、PGDH、PSAT和PSP编码基因的表达进行遗传操作和启动子进行表达分析，以了解它们在L-Ser代谢调控中的作用；利用这些获得的转基因材料和一些已报道的植物激素响应报告株系及信号途径突变体，将进一步结合外源L-丝氨酸的处理实验，探索L-Ser在调节根发育方面与植物激素间的相互作用，研究L-Ser水平升高后引起叶片衰老与活性氧产生及相关代谢酶间的关系，对蛋白酶表达和活性的调节，以揭示丝氨酸作用的分子机制。

中文关键词： 丝氨酸；光呼吸；磷酸丝氨酸途径；作用机制；相互作用

英文摘要： L-serine is a basic amino acid, which can be synthesized in plant, and should be kept at an adequate level for normal growth and development. However, elevation of the level of L-Ser in the cell was found to be able to affect the growth of main root and promote the development of lateral ones, to cause the senescence and death of leaves, and even to play significant roles in resistance under stress. Therefore, regulation of endogenous L-Ser level is very important for the normal growth and development, and the adaptation of plant to the changes in environmental conditions, and the molecular mechanism underlying should be extensively studied. In this research, we will manipulate the expression of SHMT4, SHMT5, SGAT, PGDH, PSAT and PSP in Arabidopsis, all of which are important enzymes involved in L-serine metabolism, in order to uncover their roles in the regulation of their correlated metabolism. Using the transgenic plant lines obtained by genetic transformation and selection, phytohormone response report lines and mutant lines reported formerly, and with the treatment of exogenous L-serine, we will further analyze the cross-talk between L-serine and phytohormones, such as auxin, ethylene and abscisic acid, in the regulation of root development. We will also investigate the changes in reactive oxygen species (R

英文关键词： L-Ser；photorespiration；PPSB pathway；mechanism；interaction