Regulation of SR160/tBRI1 By Systemin, Brassinosteroids and Ultraviolet-B Radiation

Systemin、油菜素类固醇和 UV-B 辐射对 SR160/tBRI1 的调节

• 批准号: 0418890
• 负责人: Johannes Stratmann
• 金额: $ 32.97万
• 依托单位: University South Carolina Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0418890&HistoricalAwards=false
• 关键词: Regulation; SR160; tBRI1; Systemin; Brassinosteroids

Plant cells are well equipped to sense and integrate endogenous and environmental signals. Signal perception is one of the most basic processes that enables plants to develop into mature, fertile organisms. One of the most surprising recent discoveries in plant science was that the SR160 cell surface receptor for the wound signaling peptide systemin is identical to the tBRI1 receptor for brassinosteroids, steroidal plant hormones that regulate growth and development. Furthermore, the systemin receptor might be co-opted by ultraviolet-B radiation. While systemin and brassinosteroids are ligands for the same receptor, their signal transduction and target genes are known to be different. On the other hand, UV-B- and systemin-induced signaling and gene expression overlap. This project is concerned with the regulation of the membrane-spanning SR160/tBRI1 receptor by systemin, brassinosteroids, and UV-B at the biochemical and molecular level. It is hypothesized that either the mode of activation of SR160/tBRI1 or the recruitment of other intracellular signaling proteins to SR160/tBRI1 differs in a ligand-dependent manner. Using tomato and tobacco as model plants, the focus will be on the activation by phosphorylation of the intracellular domain of the receptor, and on the identification and characterization of interacting proteins. In addition, it will be tested whether UV-B activates SR160/tBRI1 and recruits the same proteins to the receptor as systemin. The hypotheses will be tested experimentally by employing phosphorylation assays, the yeast two-hybrid system to identify SR160/tBRI1 interacting proteins, and a protoplast transient transformation system for in vivo studies. The project should lead to fundamental insights into stress perception that will be useful for devising strategies for generating plants with increased resistance to various stress factors. These plants would reduce the application of environmentally harmful agrochemicals such as pesticides and increase the yield of crop plants under unfavorable environmental conditions. The project will involve a postdoctoral research associate and undergraduate students who will be trained in state-of-the-art methods in plant molecular biology. Research related to this project will be incorporated in an upper level class for undergraduate and graduate students, taught by the PI. Underrepresented groups will be actively recruited to participate in the project.

植物细胞能够很好地感知和整合内源和环境信号。信号感知是使植物发育成成熟、可育生物体的最基本过程之一。最近在植物科学中最令人惊讶的发现之一是，伤口信号肽系统素的SR 160细胞表面受体与油菜素类固醇的tBRI 1受体相同，油菜素类固醇是调节生长和发育的甾体植物激素。此外，紫外线-B辐射还可能对系统素受体产生协同作用。虽然系统素和油菜素类固醇是相同受体的配体，但它们的信号转导和靶基因是不同的。另一方面，UV-B和系统素诱导的信号和基因表达重叠。本项目关注的是系统素、油菜素类固醇和UV-B在生物化学和分子水平上对跨膜SR 160/tBRI 1受体的调节。假设SR 160/tBRI 1的激活模式或其他细胞内信号蛋白向SR 160/tBRI 1的募集以配体依赖性方式不同。使用番茄和烟草作为模式植物，重点将是通过受体的胞内结构域的磷酸化激活，以及相互作用蛋白的鉴定和表征。此外，还将测试UV-B是否激活SR 160/tBRI 1，并招募与系统素相同的蛋白质到受体。将采用磷酸化试验，酵母双杂交系统，以确定SR 160/tBRI 1相互作用的蛋白质，并在体内研究的原生质体瞬时转化系统的实验测试的假设。该项目将导致对压力感知的基本见解，这将有助于设计策略，以产生对各种压力因素具有更高抗性的植物。这些植物将减少对环境有害的农用化学品如杀虫剂的施用，并在不利的环境条件下增加作物的产量。该项目将涉及一名博士后研究助理和本科生，他们将接受植物分子生物学最先进方法的培训。与此项目相关的研究将被纳入由PI教授的本科生和研究生的上层课程。将积极招募代表性不足的群体参与该项目。