PAD4是非常重要的植物免疫调控蛋白，它和SAG101分别与EDS1形成二聚体，共同介导了TIR-NB-LRR类型受体蛋白激活的抗性。但我们对PAD4和EDS1调控免疫反应的分子机制，以及它们直接调控的下游元件知之甚少。本项目中，我们巧妙地利用点突变PAD4MLF抗病功能正常而与EDS1互作减弱的特点，通过免疫共沉淀结合质谱分析技术纯化鉴定到5个感兴趣的PAD4MLF的候选互作蛋白，命名为PADAPs。其中PADAP1特异地与PAD4互作，而不与EDS1和SAG101互作。我们还发现表达N端PAD4和C端SAG101的融合蛋白导致植物的免疫自激活，这为研究PAD4分子机制提供了新工具和新线索。以此为基础，本项目将研究PAD4/EDS1与PADAPs的功能和分子联系，研究融合基因介导免疫自激活的机制，旨在揭示PAD4和EDS1这两个重要免疫调控元件传递免疫信号的分子机制。

PAD4 is an important regulator in plant immunity. PAD4 and its sequence related protein SAG101 forming heterodimer with EDS1 respectively are required for almost all TIR-NB-LRR receptor-mediated resistance. However, the direct components regulated by PAD4/EDS1 and the molecular mechanisms of PAD4/EDS1 in immunity are still largely unknown. In this proposal, we used PAD4 with mutations in three amino-acid residues, named as PAD4MLF, which fully function in immunity but has dramatically reduced interaction with EDS1. Taking advantage of the PAD4MLF variant, we have identified five interesting PAD4-interacting candidates (named as PADAPs) by immunoprecipitation of PAD4MLF followed with Mass spectrometry. Among them, PADAP1 specifically interacts with PAD4, but not with EDS1 or SAG101. We also found that expression of a chimera protein (N-terminal PAD4 fused to C-terminal SAG101) in plants results in auto-immunity. This provides a new clue and a new tool for studying the molecular mechanisms of PAD4. Based on these results, we aim to study the functions of PADAPs and how they were regulated by PAD4/EDS1 in immunity, and the molecular mechanisms of the PAD4-SAG101 chimera-triggered auto-immunity. The findings will shed light on the regulative mechanism of PAD4/EDS1 in plant immune system.