阐明病原菌与寄主植物之间的相互作用，可为作物分子遗传改良提供重要的理论基础。通过丁香假单胞菌–拟南芥互作系统，研究三型效应蛋白与植物免疫蛋白之间的互作机制，是实现上述目标的理想研究系统。在前期工作中，申请者通过酵母双杂交筛选，发现植物免疫信号分子PBS3与EDS1存在相互作用，且PBS3促进了EDS1的蛋白稳定性；同时发现三型效应蛋白HopAA1-1与PBS3及EDS1均存在相互作用，并可显著降低PBS3与EDS1的蛋白表达水平。本项目拟以PBS3、EDS1以及HopAA1-1三者的相互作用为切入点，深入研究PBS3-EDS1蛋白复合体在植物免疫反应中的作用以及与三型效应蛋白HopAA1-1的互作机制。研究结果将有望揭示新的参与植物免疫信号转导的重要蛋白复合体PBSS3-EDS1的工作机制，为通过基因工程手段提高植物的抗病性提供新的操作靶标与理论依据。

Understanding of the interaction between pathogens and plants can provide theoretical basis for crop genetic improvement. Pseudomonas syringae-Arabidopsis thaliana system is an appropriate model system for experimental characterization of the molecular mechanism of pathogen-plant interactions. In previous works, we identified a novel protein-protein interaction between PBS3 and EDS1 by yeast two-hybrid assay, and proved that PBS3 plays a role in the maintenance of EDS1 protein stability. Another finding was that one type III effector from Pseudomonas syringae, HopAA1-1, can interact with both PBS3 and EDS1. More importantly, HopAA1-1 can cause severe decrease of PBS3 and EDS1 protein levels. Therefore, the specific aims of this project are to investigate the function of PBS3-EDS1 protein complex in plant immunity and the interaction mechanism of this protein complex with the type III effector HopAA1-1. Our results are expected to reveal the working mechanism of PBS3-EDS1 protein complex in plant immunity, and this will provide new theoretical basis and operation target for genetic engineering operation to improve plant disease resistance.