CAREER: Dissecting the Molecular Regulation of Septin-Mediated Plant Invasion by the Blast Fungus Magnaporthe Oryzae

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。稻瘟病菌会导致栽培水稻和小麦的一种极具破坏性的疾病，称为稻瘟病，对世界各地的粮食安全构成持续威胁。在田间，稻瘟病是使用有限范围的杀菌剂来防治的，而对这些化学物质的抗药性的出现是一个迫在眉睫的威胁。因此，迫切需要开发新的策略来控制稻瘟病，但这需要从更全面的机制上了解稻瘟病菌的感染生物学。为了感染植物，米根霉产生一种特殊的产生压力的感染细胞，称为附着胞，它用来打破叶子的内部。这项研究的重点是更好地了解这些感染细胞是如何构建的以及它们是如何工作的，因此结果可能有助于维护全球粮食安全和提高农业生产率。拟议的活动将为植物、微生物及其相互作用的研究提供更好的生物成像培训和教育，并将为低收入家庭和第一代高中生提供更多机会，获得尖端真菌细胞生物学的实践研究经验，从而促进他们参与高等教育和科学。在当地活动中传播这些研究成果将提供更多的公众参与机会，导致科学素养和意识的提高，以及对科学和科学家的更大信任。附着胞介导的米曲霉入侵植物需要在其碱基内调节组装环状结构，该结构由一类形成细胞骨架细丝的GTP结合蛋白组成，称为Septins。这种感染特异的隔素环是如何在正确的地点和正确的时间，在发育中的附着胞内形成的，从而使植物能够入侵，在很大程度上仍然是个谜。事实上，了解Septins如何在不同的细胞类型中组装并动态重塑为不同的功能结构是该领域的当前前沿。关键的是，对稻瘟病菌中隔质环组装和功能的机械理解的改进可能有助于开发新的杀菌剂来控制稻瘟病和其他真菌作物病害，特别是考虑到植物不含隔质蛋白。这个项目的目标是获得新的分子机制，通过这些分子机制，早期的隔质盘状结构在附着体的底部形成并重塑成环，以及这些皮质结构如何组织植物入侵的穿透界面。该项目结合了时间分辨邻近蛋白质组学、活细胞成像和反向遗传学的使用，从功能上绘制了Septin组织的附着胞基皮层和渗透界面的图谱，并采用了一种基于荧光显微镜的全基因组化学突变筛选来确定Septin环组装的新调节因子。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117- 2) The fungus Magnaporthe oryzae causes a highly destructive disease of cultivated rice and wheat, called blast, which poses an ongoing threat to food security around the world. In the field, blast is combatted using a limited range of fungicides, and the emergence of resistance to these chemistries is a looming threat. Thus, there is an urgent need to develop new strategies to control blast, but this demands a more complete mechanistic understanding of M. oryzae infection biology. To infect plants, M. oryzae produces a specialized pressure-generating infection cell, called an appressorium, which it uses to break inside of leaves. This research focuses on gaining a better understanding of how these infection cells are built and how they work, and therefore the outcomes may help to safeguard global food security and enhance agricultural productivity. The proposed activities will provide improved training and education in bioimaging for the study of plants, microbes and their interactions, and will provide enhanced opportunities for low-income, and first-generation high school students to gain hands-on research experience in cutting-edge fungal cell biology, therein promoting their participation in higher-education and science. Communication of these research outcomes at local events will provide enhanced opportunities for public engagement, leading to increased scientific literacy and awareness and greater trust in science and scientists.Appressorium-mediated plant invasion by M. oryzae requires the regulated assembly of a toroidal ring structure, composed of a class of cytoskeletal filament-forming GTP-binding proteins called septins, within its base. How this infection-specific septin ring forms in the right place, and at the right time, within the developing appressorium to enable plant invasion, remains largely mysterious. Indeed, understanding how septins are assembled and dynamically remodeled into different functional architectures in diverse cell types is a current frontier in the field. Critically, improved mechanistic understanding of septin ring assembly and function in M. oryzae may inform the development of new fungicides to control blast, and other fungal crop diseases, especially given that plants do not contain septins. The goals of this project are to gain new insight into the molecular mechanisms by which incipient septin disc-like structures form in the base of appressoria and are remodeled into rings, and how these cortical structures organize the penetration interface for plant invasion. This project combines the use of time-resolved proximity proteomics, live cell imaging, and reverse genetics to functionally map the septin-organized appressorium basal cortex and penetration interface and employs a novel fluorescence microscopy-based genome-wide chemical mutagenesis screen to identify novel regulators of septin ring assembly.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.