Antimicrobial Plant Defensins:Structure-Activity Relationships and Modes of Action

抗菌植物防御素：结构-活性关系和作用模式

• 批准号: 0924124
• 负责人: Dilip Shah
• 金额: $ 50万
• 依托单位: Donald Danforth Plant Science Center
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0924124&HistoricalAwards=false
• 关键词: Antimicrobial; Plant; Defensins; Structure; Activity

Intellectual Merit Plants constantly encounter pathogen attacks, especially from pathogenic fungi. As part of various defense strategies to protect themselves against fungal attack, plants produce small antifungal proteins known as defensins. Defensins are produced during the normal growth and development of plants and also in response to fungal attack. Some of these proteins are potent inhibitors of fungal pathogens. The PI and his research team have isolated two plant defensins, MsDef1 and MtDef4, from Medicago spp. that inhibit the growth of Fusarium graminearum, a fungal pathogen which causes devastating head blight disease in wheat and barley. The constitutive expression of these proteins in transgenic plants affords strong protection from fungal attack. A critical issue that needs to be addressed for effective use of these proteins in transgenic crops is understanding their structure-activity relationships, modes of action and the mechanisms by which fungal resistance to these proteins might emerge. Preliminary data suggest that MsDef1 and MtDef4 have different modes of antifungal action and act independently on F. graminearum. The planned research will identify the structural features and active sites that are essential for the unique antifungal activity of these proteins. In addition, the fungal toxicity pathway utilized by each protein will be elucidated. Broader ImpactsThe planned research will shed light on the molecular mechanisms by which antifungal plant defensins inhibit the growth of fungi. This knowledge will enable an effective long-term use of these proteins for biological control of fungal pathogens in transgenic crops. The research will also help establish the foundation for crop and mammalian safety, thus providing a greater sense of security about the use of these proteins in transgenic crops. Moreover, knowledge gained from the planned studies will facilitate future discovery of environmentally safe fungicides. In addition, this project provides a training opportunity for a postdoc as well as minority undergraduates and high school students. The PIs will continue to coordinate with and provide research opportunities through existing programs for students at the Danforth Center. Participants will learn not only protein biochemistry and engineering, but also cutting-edge fungal genomics and proteomics technologies. To enhance the wider scientific impact, presentations at professional meetings and publications in peer-reviewed journals are planned.

智力优势 植物经常受到病原体的攻击，特别是来自病原真菌的攻击。 作为保护自己免受真菌攻击的各种防御策略的一部分，植物产生称为防御素的小抗真菌蛋白。 防御素在植物的正常生长和发育过程中产生，也响应于真菌的攻击。 这些蛋白质中的一些是真菌病原体的有效抑制剂。 PI和他的研究小组已经从苜蓿属中分离出两种植物防御素MsDef 1和MtDef 4。抑制禾谷镰刀菌的生长，禾谷镰刀菌是一种真菌病原体，在小麦和大麦中引起毁灭性的赤霉病。 这些蛋白质在转基因植物中的组成型表达提供了对真菌攻击的强保护。 为了在转基因作物中有效利用这些蛋白质，需要解决的一个关键问题是了解它们的结构-活性关系、作用模式和真菌对这些蛋白质的抗性可能出现的机制。 初步数据表明MsDef 1和MtDef 4具有不同的抗真菌作用模式，并且独立地对F.禾谷早熟禾 计划中的研究将确定这些蛋白质独特抗真菌活性所必需的结构特征和活性位点。 此外，将阐明每种蛋白质所利用的真菌毒性途径。 更广泛的影响计划中的研究将揭示抗真菌植物防御素抑制真菌生长的分子机制。 这些知识将使这些蛋白质的生物控制转基因作物中的真菌病原体的有效的长期使用。 这项研究还将有助于为作物和哺乳动物的安全性奠定基础，从而为在转基因作物中使用这些蛋白质提供更大的安全感。 此外，从计划的研究中获得的知识将有助于未来发现环境安全的杀真菌剂。 此外，该项目还为博士后以及少数民族本科生和高中生提供了培训机会。 PI将继续协调，并通过现有的计划为丹佛斯中心的学生提供研究机会。 参与者不仅将学习蛋白质生物化学和工程，还将学习前沿的真菌基因组学和蛋白质组学技术。 为了扩大科学影响，计划在专业会议上作专题介绍，并在同行评审的期刊上发表文章。