Molecular Characterization of Plant-Bacterial Interactions

长期以来，宿主-细菌相互作用一直是我研究的一个浓厚兴趣。我之前发现了一种由病原细菌分泌的蛋白酶IV，它能强烈地激活植物的免疫反应。参与感知蛋白酶IV的植物寄主的防御反应通路以前还没有被描述过。此外，我还发现其他植物病原菌中的类似蛋白水解酶可以影响作物的防御反应，这表明对该酶的研究可能揭示农业上重要的防御途径。该计划的总体目标是试图了解植物寄主和病原体在感染过程中是如何作为一个综合系统运行的，并利用这些研究的知识来开发新的策略来防御植物免受病原体攻击。*目标1中的项目将侧重于识别植物途径中的未知成分，以感知蛋白酶IV。对这些已识别成分的后续功能研究将有助于将它们置于植物先天免疫系统的全面信号网络中。有趣的是，我的数据还表明，蛋白酶作为一种毒性因子发挥作用，对植物的免疫反应具有相反的影响。在目标1中提出的其他实验将调查蛋白酶IV在引起植物寄主疾病症状中的作用。这项研究计划的目标2中提出的实验将试图识别细菌合成和分泌的其他蛋白质，并了解它们如何影响植物宿主的免疫反应。目标2中的项目的另一个目标是了解植物宿主和细菌病原体作为一个整体在感染过程中是如何运作的。第一步将是调查它们的基因表达模式的变化。然后，这项研究的知识将被用来开发新的方法来防御病原体的攻击。*这项研究计划的总体目标是利用一系列不同的方法来弄清楚细菌分泌蛋白影响宿主免疫反应的确切机制，并帮助植物研究人员了解植物天然免疫信号通路是如何相互联系的。通过这个研究计划中提出的各种项目，我将解决植物-病原菌相互作用领域中的几个重要问题。此外，对植物寄主中毒力相关蛋白和防御反应激活物的研究将有助于更深入地了解寄主免疫与细菌致病之间的进化军备竞赛模式。*总而言之，这项工作将有助于我们理解植物免疫信号通路的分子基础，并从长远来看，在加拿大保持环境友好、可持续的农业实践的同时，为提高农业生产做出贡献。**

Host-bacterial interaction has been a keen interest of my research for a long term. I previously identified a protease secreted by pathogenic bacteria, protease IV, which strongly activates a plant immune response. The defense response pathway in plant hosts that are involved in the perception of protease IV has not been previously characterized. In addition, I found that similar proteases in other plant pathogens could affect defense response in crop plants, indicating that the study of this protease could unveil agriculturally important defense pathways. The overall goal of the proposed program is to try to understand how plant hosts and pathogens operate as an integrated system during the process of infection and to use the knowledge from these studies to develop novel strategies to defend plants against pathogen attack. *** The projects in Aim 1 will focus on the identification of unknown components in the plant pathway for protease IV perception. The subsequent functional studies of these identified components will help place them into a comprehensive signaling network of the plant innate immune system. Interestingly, my data also suggest that protease functions as a virulence factor that has the opposite effect on the plant immune response. Additional experiments proposed in aim 1 will investigate the roles of protease IV in causing disease symptoms in plant hosts. The experiments proposed in Aim 2 of this research program will try to identify other proteins that are synthesized and secreted by bacteria and understand how they can affect immune responses in plant hosts. An additional goal of the projects in Aim 2 is to understand how both plant hosts and bacterial pathogens, as a whole system, operate during the process of infection. The initial step will be the investigation of the changes in their gene expression patterns. Then, the knowledge from this study will be used to develop new approaches to defend against pathogen attack.*** The overall goal of this research program is to utilize a collection of different approaches to figure out the precise mechanism by which bacterially secreted proteins affect the host immune response and to help plant researchers understand how plant innate immune signaling pathways are interconnected. Through various projects proposed in this research program, I will address several important questions in the field of plant-pathogen interactions. Moreover, the examination of both the virulence-related proteins and the activators of defense responses in plant hosts will provide a more thorough understanding of the evolutionary arms race model between host immunity and bacterial pathogenicity. *** In summary, this work will contribute to our understanding of the molecular basis of immune signaling pathways in plants and contribute in the long run to enhanced agricultural production while maintaining environmentally friendly, sustainable agricultural practices in Canada. **