与NPR1互作的小麦条锈菌效应蛋白PNPi (Puccinia NPR1 interactor) 的功能解析

“Effectors” secreted by stripe rust are assumed to be the key governing factor that determines pathogenesis in wheat. Due to it is biotrophic and not transformed artificially, functional characterization of rust effector is becoming bottleneck in revealing pathogenesis of wheat stripe rust. In our previous study, it was reported that the stripe rust effector PNPi interfered with the PR gene expression, which was competitively binding NPR1 that is the key regulator of SA pathway with transcription factor TGA2. However, it is not known that how PNPi suppresses host resistance and what the function of PNPi is. Therefore, the characterizations of protein structure and localization of PNPi here by transit expression, immune colloidal gold technique will advance the understanding of PNPi-host interaction. The further functional characterization of PNPi both in host and rust colonization supporting by CRISPR/Cas9 and omics technology will reveal the overall functions of PNPi, which will be benefit to detect the new strategy and targets for wheat stripe rust disease control.

条锈菌效应蛋白是致使小麦感染条锈病的主要功能因子。由于该致病菌目前尚未实现遗传转化，效应蛋白的生物学功能解析是目前条锈菌致病机理研究的瓶颈。我们前期研究发现：具有RxLR-dEER特征基序的小麦条锈菌效应蛋白PNPi通过C端的保守结构域与转录因子TGA2竞争性的结合SA抗病信号途径关键调节蛋白NPR1来抑制寄主抗性，但具体作用的分子机理和该效应蛋白的功能不清楚。据此，本研究采用体外瞬时表达、免疫胶体金等技术，系统研究PNPi蛋白C端的结构特征、靶向定位与致病功能的关系，进一步阐明PNPi靶向NPR1操控寄主抗性的作用机理；其次利用CRISPR/Cas9编辑技术结合高通量代谢组及转录组测序等方法，全面解析该效应蛋白在寄主致病过程中的作用靶标和信号通路及其在条锈菌生长繁殖过程中的生理生化功能，为小麦条锈病防治提供新思路和新靶点。