泛素连接酶支架蛋白BPM1在玉米免疫受体Rp1-D21所介导抗病防卫反应中的功能与分子机理研究

免疫受体R蛋白介导的抗性在减少作物病害损失方面发挥了巨大作用。为高效利用这种抗性，必须深入解析R蛋白的作用机理。这类研究是当前植物抗病领域的重要前沿和热点，旨在挖掘R蛋白的新颖互作蛋白，为其功能解析与改良提供新途径。在本项目中，我们拟深入解析泛素连接酶支架蛋白BPM1在玉米NLR类R蛋白Rp1-D21介导抗性中的作用。前人对植物BPM1及其同源蛋白的研究主要集中在发育和抗旱方面，其在抗病中的作用还未见报道。我们发现BPM1可与Rp1-D21互作，并改变其亚细胞定位和抑制其介导的过敏抗性反应。在此基础上，本项目将解析BPM1如何调控Rp1-D21的亚细胞定位与蛋白稳定性，并揭示BPM1表达水平的精细调控是否可用于玉米抗性的遗传改良。总之，本项目将率先在国际上阐明泛素连接酶支架蛋白参与NLR蛋白介导抗性的分子机制，为理解NLR蛋白的作用机理提供新知识，并为更加高效地利用NLR蛋白提供新途径。

The resistance mediated by immune receptor R proteins has played a major role in decreasing the damages caused by plant diseases. To more effectively utilize R protein-mediated resistance in crop production, it is essential to deeply dissect and understand the mechanisms involved. This type of studies is currently at the forefront of plant disease resistance research, with the aims being to uncover novel functional partners of R proteins so as to provide new avenues for further investigating and enhancing R protein-mediated disease resistance. In this proposal, we aim to reveal the function of BPM1, an adaptor in ubiquitin E3 ligase complex, in the defense response conditioned by Rp1-D21, which is a nucleotide-binding and leucine-rich-repeat type of R protein. A role for BPM1 and homologous proteins in R protein mediated defense response has not been reported before, as previous studies on these proteins are largely related to their involvement in plant development and drought response. Our preliminary observation shows that BPM1 physically interacts with Rp1-D21, which is associated with altered intracellular distribution patterns of Rp1-D21 and compromisation of Rp1-D21 augmented defense. On this basis, we will further elucidate the mechanisms underlying the regulation of Rp1-D21 distribution and function by BPM1, and to explore the feasibility of fine-tuning BPM1 expression for improving maize disease resistance. In essence, the work in this proposal will take the lead in discovering and dissecting the function of ubiquitin ligase adaptor in R protein-mediated defense response. This will expand our understanding on the functional mechanisms of NLR proteins, and likely yield new paths for more effectively studying and utilizing plant immune receptor proteins in crop protection.