KINASE MEDIATED SIGNALING IN THE RICE DEFENSE RESPONSE

受体激酶 (RK) 在机制中发挥着重要作用 哪些生物体感知环境信号并做出反应；调节 动物和植物的生长和发育。长期目标是 拟议的项目是引发受监管的信号交易级联 由 RK 提供。这些信息将增强我们对细胞的理解 动物体内的转化和致癌并导致发育 植物病害控制的环境安全策略。 拟议项目的短期目标是建立因果关系 病原体诱导的水稻受体样激活之间的联系 激酶、XA21 和下游防御反应。根据信息 根据动物系统中的受体酪氨酸激酶，我们假设 XA21 的催化结构域在 XA21 介导的信号中起关键作用 转导和作为细胞内结合位点的特定残基 蛋白质。然后这些蛋白质可以直接或间接转导各种 防御反应。我们还假设病原体可能分泌 影响信号转导途径的宿主细胞因子。 为了部分支持这些假设，我们发现 胞内结构域可以在体外进行自身磷酸化，即 病原体 GTP 结合蛋白和水稻过氧化氢酶特异性相互作用 植物中的 XA21 正在经历抗性反应。为了测试这些 假设，我们建议实现以下目标： 1. 确认 磷酸化在 XA21 介导的抗病性中的重要作用。 2. 鉴定并表征与 Xa21- 相互作用的水稻蛋白 激酶。 3. 表征防御反应和防御相关基因 XA21 介导的防御途径中的表达。 4. 确定 xoo/GBP 相互作用的生物学意义。的成就 拟议的目标将首次导致建立 植物受体激酶与相关蛋白之间的因果关系 下游响应。

Receptor kinases (RKs) play an important role in the mechanisms witch which organisms perceive and respond to environmental signals; regulating growth and development in both animals and plants. The long-term goal of the proposed project is to elicit the signal transaction cascade regulated by RKs. This information will enhance our understanding of cellular transformation and carcinogenesis in animals and lead to the development of environmentally safe strategies for disease control in plants. The short-term goal of the proposed project is to establish the causal connection between pathogen induced activation of the rice receptor-like kinase, XA21, and the downstream defense responses. Based on information from receptor tyrosine kinases in animal systems, we hypothesize that the catalytic domain of XA21 plays a key role in XA21-mediated signal transduction and that specific residues as binding sites for intracellular proteins. These proteins may then directly or indirectly transduce various defense responses. We also hypothesize that the pathogen may secrete factors into the host cell that influence the signal transduction pathway. In partial support of these hypotheses, we have found that the intracellular domain can autophosphorylate itself in vitro, that a pathogen GTP-binding protein and a rice catalase interact specifically with the XA21 in plants undergoing a resistance response. To test these hypotheses, we propose to carry out the following objectives: 1. Confirm the essential role of phosphorylation in XA21-mediated disease resistance. 2. Identify and characterize rice proteins that interact with the Xa21- kinase. 3. Characterize the defense response and defense-related gene expression in the XA21-mediated defense pathway. 4. Determine the biological significance of the xoo/GBP interaction. Accomplishments of the proposed objectives will, for the first time, lead to the establishment of the causal connection between a plant receptor kinase and the associated downstream response.