EAGER: Understanding the mechanisms of action of two diverse antifungal plant defensins

EAGER：了解两种不同抗真菌植物防御素的作用机制

• 批准号: 1955461
• 负责人: Dilip Shah
• 金额: $ 30万
• 依托单位: Donald Danforth Plant Science Center
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-15 至 2022-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1955461&HistoricalAwards=false
• 关键词: EAGER; Understanding; mechanisms; action; two

Crop diseases caused by fungal pathogens lead to tremendous economic losses and threaten food security worldwide. Chemical fungicides, crop rotation and natural genetic resistance don't provide adequate control of these diseases. At present, fungal diseases remain a key battlefront for reducing pre-and post-harvest losses of crop yield. Plants produce a large number of antifungal peptides as part of a complex set of multi-tiered defense strategies. Small cysteine-rich antifungal peptides called defensins exhibit potent broad-spectrum antifungal activity. This project seeks insight into the mechanisms that govern antifungal activity of two very different antifungal defensins from a model legume. This knowledge will facilitate use of these peptides as effective and sustainable biological fungicides in agriculture. Importantly, this project provides the opportunity to train the postdoctoral fellow and under-represented minority undergraduate students. Students and the postdoctoral fellow will be broadly trained in protein biochemistry, molecular biology and fungal cell biology so as to better prepare them for future careers in science. Research experiences will also be provided to K-5 teachers from low performing public schools in the St Louis area so that they can make connections between knowledge acquired in the classroom and research conducted in the laboratory. The goal of this project is to elucidate molecular mechanisms governing the potent antifungal activity of two plant defensins from a model legume Medicago truncatula. These defensins kill economically important fungal pathogens at low concentrations. These peptides bind to bioactive phospholipids in the plasma membrane of a fungal pathogen and antifungal activity of each defensin is a function of which phospholipid(s) it targets. This project will uncover sequence motifs governing phospholipid specificity and recognition for these peptides. Molecular mechanisms by which these peptides gain access to the cytoplasm of a wheat fungal pathogen Fusarium graminearum will be identified. In addition, systematic biochemical and proteomics approaches will be undertaken to identify intracellular protein targets of these peptides in this pathogen. The fully completed and annotated genome sequence of this fungus and its functional genomics database will provide essential resources for the research. Detailed mechanistic understanding of the antifungal action of these peptides will enable a more realistic prediction of their antifungal activity in a complex environment of the host plant and design of more effective peptides for disease control.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.

由真菌病原菌引起的作物病害在世界范围内造成巨大的经济损失，威胁着粮食安全。化学杀菌剂、作物轮作和自然遗传抗性不能充分控制这些疾病。目前，真菌病害仍然是减少作物收获前和收获后产量损失的关键战场。植物产生大量的抗真菌肽作为一套复杂的多层防御策略的一部分。被称为防御素的小的富含半胱氨酸的抗真菌肽具有强大的广谱抗真菌活性。该项目旨在深入了解控制两种非常不同的抗真菌防御素的抗真菌活性的机制。这些知识将促进这些肽在农业中作为有效和可持续的生物杀菌剂的使用。重要的是，该项目为培养博士后和少数民族本科生提供了机会。学生和博士后将在蛋白质生物化学、分子生物学和真菌细胞生物学方面接受广泛的培训，以便为他们未来的科学事业做好更好的准备。研究经验也将提供给来自圣路易斯地区表现不佳的公立学校的K-5教师，以便他们能够将课堂上获得的知识与实验室进行的研究联系起来。本项目的目的是阐明模式豆科植物紫花苜蓿中两种植物防御素的有效抗真菌活性的分子机制。这些防御素在低浓度下杀死经济上重要的真菌病原体。这些肽与真菌病原体质膜中的生物活性磷脂结合，每种防御素的抗真菌活性是其靶向磷脂的功能。该项目将揭示控制这些肽的磷脂特异性和识别的序列基序。这些肽进入小麦真菌病原菌镰刀菌细胞质的分子机制将被确定。此外，将采用系统的生化和蛋白质组学方法来确定这些肽在该病原体中的细胞内蛋白靶点。完整的基因组序列及其功能基因组数据库将为该真菌的研究提供必要的资源。详细了解这些肽的抗真菌作用机制将有助于更现实地预测其在宿主植物复杂环境中的抗真菌活性，并设计更有效的疾病控制肽。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。