Interception of the fungal haustorium by the plant broad-spectrum resistance protein RPW8 (II)

许多真菌和卵菌病原体侵入植物时，具有一种称为吸器的特殊感染结构，吸器从寄主细胞中获取营养，是病原体引起植物严重疾病的机制。作为回应，植物进化出了复杂的防御机制来对抗这种感染。宿主-病原体识别和防御信号的机制已被广泛研究；然而，人们对宿主-病原体结构界面（即吸器外膜）上的分子战机制知之甚少。研究人员发现，RPW8是一种在拟南芥中赋予对白粉病广谱抗性的蛋白质，它专门针对白粉病吸器的EHM；在这个位置，RPW8激活防御系统来限制吸器。通过结合突变、细胞生物学、遗传和生化方法，研究人员在这个项目中旨在了解RPW8.2如何激活这种抗性。具体而言，研究人员将定义RPW8.2中功能重要的基序和单个氨基酸，确定将RPW8.2靶向EHM的运输线索，并表征2C型蛋白磷酸酶在RPW8.2介导的防御调节中的作用。该项目的结果不仅将阐明rpw8.2介导的广谱霉菌抗性的分子基础，还将为作为植物先天免疫关键组成部分的靶向蛋白运输提供新的机制见解。吸器形成真菌和卵菌病原体对世界粮食安全构成持续威胁。该项目的发现将有助于设计针对这些病原体的新型抗性策略，具有改善作物生产和保护环境的潜力。该项目将为高中生和本科生，特别是来自代表性不足群体的学生提供科学培训和研究机会；它还将为一名研究生和一名博士后提供广泛的研究培训，为他们从事科学事业做好准备。

Many fungal and oomycete pathogens invade plants with a specialized infection structure named the haustorium, which derives nutrients from the host cell and is a mechanism by which pathogens can cause serious plant diseases. In response, plants have evolved elaborate defense mechanisms to fight against such infection. Mechanisms of host-pathogen recognition and defense signaling have been extensively studied; however, very little is known about the mechanisms of molecular warfare at the host-pathogen structural interface known as the extra-haustorial membrane (EHM). The investigators discovered that RPW8, a protein conferring broad-spectrum resistance against powdery mildew in the plant Arabidopsis , is specifically targeted to the EHM, which encases the haustorium of powdery mildew ; in this location, RPW8 activates defenses to constrain the haustorium. Using a combination of mutational, cell biological, genetic and biochemical approaches, the investigators aim in this project to understand how RPW8.2 activates this resistance. Specifically, the investigators will define functionally important motifs and individual amino acids in RPW8.2, identify the trafficking cues for targeting RPW8.2 to the EHM, and characterize the role of a protein phosphatase type 2C in regulation of RPW8.2-mediated defense. Results from this project will not only elucidate the molecular basis of RPW8.2-mediated broad-spectrum mildew resistance but also provide fresh mechanistic insight into targeted protein trafficking as a critical component of plant innate immunity. Haustorium-forming fungal and oomycete pathogens pose constant threats to the world's food security. Discoveries from this project will help engineer novel resistance strategies against these pathogens , with the potential for improved crop production and environmental protection. This project will provide science training and research opportunities for high school and undergraduate students, especially those from under-representative groups; it will also provide extensive research training for one graduate student and one postdoctoral associate to prepare them for careers in science.