Collaborative Research: Arabidopsis 2010: Dissecting Cortical Actin Function during Arabidopsis-Pseudomonas Interactions

植物致病菌与它们侵入的宿主细胞和组织之间存在着微妙而复杂的相互作用。新的信息表明，一个动态的纤维网络，即细胞骨架，对植物病原体的抗性和易感性都是必不可少的。然而，究竟是细菌中的哪些分子刺激了细胞骨架反应，以及哪些植物蛋白是这些反应所必需的，人们仍然知之甚少。在这个项目中，研究人员将剖析细菌效应蛋白与植物宿主细胞骨架之间串扰的遗传基础。利用分子遗传学工具和先进的成像技术，研究人员将测试特定病原体效应蛋白扰乱植物肌动蛋白结合蛋白（ABPs）的假设，这反过来导致植物防御信号传导过程中细胞骨架的改变。将开发一个肌动蛋白和肌动蛋白结合蛋白突变体工具箱，并开发一种将细菌效应物引入宿主细胞的传递系统。通过这项工作，他们的目标是鉴定细菌效应蛋白和39个植物基因/蛋白的功能，以揭示信号网络。领导PI Staiger将协调小组之间的活动，并利用最先进的成像模式来评估ABP收集中肌动蛋白动力学的缺陷和对效应蛋白的反应。Day和Chang的实验室将使用遗传学方法来分析串扰是否涉及病原体相关的分子模式识别反应（PTI）或效应触发免疫（ETI），或两者兼有。这两个实验室还将使用一种新的细菌传递系统，将肌动蛋白动力学的变化与相应的细菌效应蛋白联系起来。这两个实验室还将准备用于蛋白质相互作用测定和亚细胞定位的构建物。在这项工作中产生的所有项目数据和资源将在联合网站http://actinpathogen-network.msu.edu上及时发布。这项工作的广泛影响将有助于深入了解宿主？病原体信号将使作物改良能够防止破坏农业生产力的疾病。作为一个独特的外展组成部分，我们将建立一个夏季研讨会，培训所有项目科学家和其他感兴趣的团体，包括当地的高中生，学习细胞动力学成像的先进方法。

An exquisite and intricate crosstalk exists between bacterial phytopathogens and the host cells and tissues they invade. New information suggests that a dynamic network of filaments, the cytoskeleton, is essential for both resistance and susceptibility to plant pathogens. However, exactly which molecules from the bacterium stimulate cytoskeletal responses, and which plant proteins are necessary for these responses remains poorly understood. In this project, the investigators will dissect the genetic basis for crosstalk between bacterial effector proteins and the plant host cytoskeleton. Using both molecular genetics tools and advanced imaging technologies, the investigators will test the hypothesis that specific pathogen effector proteins perturb plant actin-binding proteins (ABPs), which in turn leads to alterations in the plant cytoskeleton during defense signaling. A toolbox of actin and actin-binding protein mutants will be developed, and a delivery system for introducing bacterial effectors into host cells will be exploited. Through this work, the PIs aim to identify the function of bacterial effector proteins and 39 plant genes/proteins in order to uncover the signaling network. Lead PI Staiger will coordinate activities between the groups and exploit state-of-the-art imaging modalities to evaluate the defects in actin dynamics in the ABP collection and in response to effector proteins. The Day and Chang laboratories will use genetic approaches to dissect whether crosstalk involves pathogen-associated molecular pattern recognition responses (PTI) or effector-triggered immunity (ETI), or both. These two labs will also use a novel bacterial delivery system to associate changes in actin dynamics to a corresponding bacterial effector protein. The two labs will also prepare constructs for protein-protein interaction assays and subcellular localization. All project data and resources created in this work will be disseminated in a timely fashion at a joint website: http://actinpathogen-network.msu.edu. The broader impact of this work will contribute to a deep understanding of host?pathogen signaling and will enable crop modifications to protect against diseases that devastate agricultural productivity. As a unique outreach component, we will establish a summer workshop to train all project scientists and other interested parties, including local high school students, in advanced methods for imaging cellular dynamics.