MLO调控白粉菌抗性的分子机理

早在上世纪90年代就发现MLO（Mildew resistance locus o）的突变可以使大麦对白粉病产生抗性，影响真菌对表皮的穿透。mlo介导的抗性非常持久，在生产上早已得到广泛应用。随后在拟南芥、番茄等多个物种中发现该基因突变都能导致对白粉病抗性的增强。MLO编码一个七次跨膜蛋白，在抗病中其生化功能不清楚。本项目拟以拟南芥和白粉菌为研究对象，通过遗传和生化的手段解析在白粉菌侵染过程中MLO的磷酸化对其抗病性的调控；鉴定与MLO相互作用的蛋白MIP；阐释MLO发挥作用的分子机理；并在黄瓜番茄等物种中验证MLO作用机理的广谱性，为提高作物的抗病性提供新的策略。

Powdery mildew is a widespread plant disease caused by ascomycete fungi of the order Erysiphales. In the 1990s, mildew resistance locus o (MLO) mutation was found to confer broad-spectrum resistance against to powdery mildew fungi in barely. On mlo mutants, powdery mildew pathogenesis is terminated at the stage of cell wall penetration and host cell entry. So far, mlo-based resistance has been described in many plant species, including Arabidopsis and tomato. MLO encodes a plasma membrance-localized seven-transmembrance protein. However, at present the bio-chemical activity of the protein remains mysterious. In this proposal, we will identify the phosphorylation sites in MLO and study their roles in regulating defense against mildew; and investigate whether MLO is involved in delivering cargos such as regulatory proteins to fungal penetration sites, uncovering the molecular mechanisms of MLO mutation conferring powdery mildew resistance. Moreover, we will test whether this is a general mechanism in different plant species. Together, our proposed research will provide new knowledge about the molecular mechanisms of plant immunity.