去N-糖基化酶GmPNGase A在大豆抗疫霉病中的作用和机制研究

质外体是寄主抵御病原菌侵染的关键战场。在侵染的早期，疫霉菌通过分泌大量的质外体致病因子干扰寄主免疫，帮助自身侵染。申请者前期研究表明，N-糖基化修饰广泛存在于疫霉菌分泌的致病因子中，对致病因子在质外体维持稳定非常重要，表明病原菌利用N-糖基化修饰武装自身致病因子是一种重要的致病机制。然而，植物在质外体中如何应对病原菌致病因子的N-糖基化修饰，仍不清楚。因此，本项目将聚焦这一科学问题，开展如下研究：1）通过去N-糖基化酶活性检测、质谱鉴定和功能域分析，鉴定大豆质外体去N-糖基化酶(GmPNGase A)；2）从生物化学和分子遗传学角度阐明GmPNGase A在大豆抵御疫霉菌侵染时的功能；3）利用糖蛋白组学鉴定GmPNGase A调控的致病因子，从而解析GmPNGase A参与寄主抗性的分子机制。研究结果可望在实践上通过遗传育种使作物获得更为广谱和持久的抗性，为制定新的疫霉菌防控策略提供指导

The apoplastic space is the initial battlefield in plant-microbe interactions. In the early stage, plant pathogens secret a repertoire of effectors to modulate host immunity and benefit infection. In our previous work, N-glycosylation is widely present in the pathogenic factors secreted by Phytophthora, which is very important for the stability of the pathogenic factors in the apoplast. N-glycosylation has gradually become an important pathogenic mechanism for pathogens to shield their effectors. However, it remains unknown that how hostplants could regulate the N-glycosylation of pathogenic effectors in apoplast to improve resistance. Therefore, based on this research, this project will focus on the scientific point, and carry out the following studies: 1) To analyze the soybean apoplastic proteins and identify the GmPNGase A through the de-N-glycosylase assay, mass spectrometry and bioinformatics technology; 2) To clarify the biochemical and biological functions of GmPNGase A in the early stage of pathogen infection via bioinformatics and molecular genetics; 3) Using glycoproteomes to identify the target protein of pathogen regulated by GmPNGase A, so as to elucidate its molecular mechanism of regulating the resistance to pathogen. The findings of the project are expected to provide guidance for genetic breeding for improving crop resistance and formulate new strategies for preventing and controlling Phytophthora disease.