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

水稻细胞中植物防御抑制与稻瘟病菌生长的分子机制

• 批准号: 1557943
• 负责人: Richard Wilson
• 金额: $ 57万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-15 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1557943&HistoricalAwards=false
• 关键词: Molecular; Mechanisms; Connecting; Plant; Defense

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.

稻瘟病由真菌 Magnaporthe oryzae 引起，是栽培稻中最严重的病害，也是全球粮食安全威胁，每年导致全球稻米产量减少 10-30%。米霉也逐渐成为小麦的主要病原体。在水稻感染期间，称为附着细胞的圆顶形真菌细胞在稻叶表面形成并进入下面的表皮细胞。值得注意的是，活水稻细胞中的真菌生长（称为生物营养）发生在感染的第一天，而不会激活通常用于保持宿主植物免受疾病侵害的强大植物防御。然而，尽管这个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整合到宿主细胞中知之甚少。为了解决这些知识差距，该提案提出以下问题：真菌细胞如何在水稻细胞中茁壮成长？为了回答这个问题，研究将针对米霉突变体的特征，这些突变体在水稻细胞中定殖的能力受损，以解开控制水稻-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稳健和可持续的缓解策略，并揭示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培训。通过解决“什么分子机制协调宿主细胞中持续真菌生长和植物防御抑制？”这一基本问题。该项目旨在解决植物病理学中有关真菌病原体在植物细胞中繁殖过程的重大问题。既定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米霉与宿主水稻细胞相比代谢的关键可利用差异。这可能会导致针对分子途径的新型作物保护策略的发展，这些分子途径对于真菌的生物营养生长至关重要，但对于宿主细胞的正常功能来说不是必需的，并且可以为细胞生长的基本原理提供新的线索。教育目标将通过刺激本科生的科学学习、为研究生进入大学后的科学生活做好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。