Molecular Mechanisms Connecting Plant Defense Suppression with Magnaporthe oryzae Growth in Rice Cells

稻瘟病由稻瘟病菌引起，是栽培水稻最严重的病害，是全球粮食安全威胁，每年导致全球水稻产量减少10-30%。M. oryzae也正在成为小麦的主要病原体。在水稻感染过程中，被称为附着胞的圆顶状真菌细胞在水稻叶片表面形成，并进入下层表皮细胞。值得注意的是，真菌在活水稻细胞中的生长，被称为生物营养，发生在感染的头几天，而没有激活通常使寄主植物免受疾病的强大植物防御。然而，尽管这一生物营养生长阶段对作物健康至关重要，但人们对植物防御抑制和真菌生长如何在宿主细胞中整合知之甚少。为了解决这些知识空白，该提案提出了以下问题：真菌细胞如何在水稻细胞中茁壮成长？为了回答这个问题，研究将针对水稻分枝杆菌在水稻细胞定植能力受损的突变体进行表征，以解锁控制水稻-真菌相互作用的基本细胞、生化和遗传调控机制。这项工作可以指出急需的强大和可持续的缓解策略，并阐明真菌的基本生长过程。拟议的工作将通过积极参与解决稻瘟病的现实问题，促进来自不同背景的博士后、研究生和本科生的分子训练。通过解决“在宿主细胞中协调真菌持续生长和植物防御抑制的分子机制是什么？”该项目旨在解决植物病理学中真菌病原体在植物细胞中茁壮成长的过程中的实质性问题。所述目标将使用正向和反向遗传学，全基因组蛋白质组学和代谢方法，以及活细胞成像来确定m.o ryzae与寄主水稻细胞在代谢方面的关键可开发差异。这可能会导致针对真菌生物营养生长至关重要但不是宿主细胞正常功能所必需的分子途径的新型作物保护策略的发展，并可能揭示细胞生长的基本原理。教育目标将通过激发本科生的科学学习，为研究生的科学生活做准备，以及激发少数民族高中生的科学兴趣来扩大科学教育。

Blast, caused by the fungus Magnaporthe oryzae, is the most serious disease of cultivated rice and a global food security threat that annually results in a 10-30% reduction in worldwide rice yields. M. oryzae is also emerging as a major pathogen of wheat. During rice infection, dome-shaped fungal cells called appressoria form on the surface of the rice leaf and access the underlying epidermal cells. Remarkably, fungal growth in living rice cells, called biotrophy, occurs for the first days of infection without activating the robust plant defenses that normally work to keep the host plant disease-free. Yet, despite the fundamental importance of this biotrophic growth stage to crop health, little is known about how plant defense suppression and fungal growth is integrated in host cells. To address these knowledge gaps, this proposal asks: How do fungal cells thrive in rice cells? To answer this, research will be directed towards characterizing mutants of M. oryzae that are impaired in their ability to colonize rice cells in order to unlock the fundamental cellular, biochemical, and genetic regulatory mechanisms that govern the rice-fungus interaction. This work could point to much needed robust and sustainable mitigation strategies and shed light on fundamental growth processes in fungi. The proposed work will foster the molecular training of postdoctoral, graduate and undergraduate students from diverse backgrounds through active participation in tackling the real-world problem of rice blast disease.By addressing the fundamental question "What molecular mechanisms coordinate sustained fungal growth and plant defense suppression in the host cell?" This project aims to resolve substantial issues in plant pathology regarding the processes by which fungal pathogens thrive in plant cells. The stated objectives will use forward and reverse genetics, genome-wide proteomic and metabolic approaches, and live-cell imaging to define key exploitable differences in the metabolism of M. oryzae compared to host rice cells. This could lead to the development of novel crop protection strategies targeting molecular pathways that are critical for the biotrophic growth of the fungus but are not required for the normal function of the host cell, and could shed new light on the basic principles of cell growth. The educational objective will expand scientific education by stimulating undergraduates' science learning, preparing graduate students for scientific life beyond the university, and inspiring scientific interest in minority high school students.