SEPBLAST: Determining the molecular basis of septin-dependent plant infection by the blast fungus Magnaporthe oryzae

该研究项目的主要目的是了解称为septins的形态发生蛋白如何调节致病真菌在植物中引起疾病的能力。植物病原真菌已经进化出专门的感染结构以进入它们的宿主。毁灭性的稻瘟病菌通过一种被称为附着胞的加压感染细胞来感染水稻，以突破植物坚韧的外层。一旦进入植物组织，真菌就会发展出第二种类型的感染结构，称为transressorium，它用来从一个水稻细胞移动到下一个。最近的证据表明，异聚septin复合物是必要的附着胞和transpressoria的功能。这个雄心勃勃的研究项目将定义Septin招募，组织和这些感染结构中的功能的分子基础。我建议评估的膜曲率依赖性septin聚集，然后确定上游组件，调节septin招聘。一个全面的隔蛋白相互作用组将被定义为两种细胞类型，使用蛋白质组学分析和邻近标记方法，在附着胞和transpressorium发展的时间序列。以这种方式，新的septin相互作用将被确定和功能上的特点。与此同时，磷酸蛋白质组学分析将被用来调查所需的Septin组装的特定磷酸化事件，并确定相应的信号通路。该项目将结合使用正向遗传筛选、靶向基因编辑、蛋白质组学分析和活细胞成像，测试以下假设：septin复合物充当真菌侵袭细胞内的主要组织中心，这是集中部署极性和毒力决定因素以实现侵袭性所需的。真菌感染细胞的侵袭性生长。

The major aim of this research project is to understand how morphogenetic proteins called septins condition the ability of a pathogenic fungus to cause disease within a plant. Plant pathogenic fungi have evolved specialised infection structures to enter their hosts. The devastating blast fungus Magnaporthe oryzae infects rice plants using a pressurised infection cell called an appressorium to breach the tough outer layer of plants. Once inside plant tissue, the fungus then develops a second type of infection structure, called a transpressorium, which it uses to move from one rice cell to the next. Recent evidence has shown that heteromeric septin complexes are necessary for the function of both appressoria and transpressoria. This ambitious research project will define the molecular basis of septin recruitment, organisation and function within these infection structures. I propose to evaluate the membrane curvature dependency of septin aggregation and then identify upstream components that regulate septin recruitment. A comprehensive septin interactome will be defined for both cell types using proteomic analysis and proximity labelling methods, during a time series of appressorium and transpressorium development. In this way, novel septin interactors will be identified and functionally characterised. In parallel, phosphoproteomic analysis will be used to investigate the specific phosphorylation events necessary for septin assembly and to identify the corresponding signalling pathways. Using a combination of forward genetic screens, targeted gene editing, proteomic analysis and live cell imaging, the project will test the hypothesis that septin complexes act as major organising centres within fungal invasive cells, required for the focused deployment of polarity and virulence determinants to enable invasive growth by fungal infection cells.