KINASE MEDIATED SIGNALING IN THE RICE DEFENSE RESPONSE

受体激酶（Receptor kinases，RKs）在细胞凋亡的机制中起重要作用， 生物体感知并响应环境信号;调节 动物和植物的生长和发育。的长期目标 建议的项目是引出信号交易级联调节 RKS的。这些信息将增强我们对细胞的理解。 转化和致癌作用，并导致发展 对环境安全的植物病害控制策略。 该项目的短期目标是建立因果关系， 病原菌诱导的水稻类受体激活与 激酶，XA 21和下游防御反应。基于信息 从动物系统中的受体酪氨酸激酶，我们假设， XA 21的催化结构域在XA 21介导的信号传导中起关键作用 转导和特异性残基作为细胞内 proteins.这些蛋白质然后可以直接或间接地与各种蛋白质结合。 防御反应。我们还假设病原体可能分泌 因子进入宿主细胞，影响信号转导途径。 在部分支持这些假设，我们已经发现， 细胞内结构域可以在体外自身磷酸化， 病原体GTP结合蛋白与水稻过氧化氢酶特异性相互作用 与植物中的XA 21进行抗性反应。测试这些 假设，我们建议进行以下目标：1。确认 磷酸化在XA 21介导的抗病性中的重要作用。 2.鉴定和表征与Xa 21- 激酶。3.鉴定防御反应和防御相关基因 在XA 21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。成就 提出的目标将首次导致建立 植物受体激酶与相关的 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.