CAREER: Rapid stem rust resistance responses in barley; non host resistance mechanisms

了解作物对微生物病原体的遗传抗性对世界粮食安全和可持续农业实践具有重要意义。为了在作物中有效地利用对重要病原体的遗传抗性，我们必须了解植物天然免疫系统不同层的潜在机制。本项目将研究大麦的条锈菌小种UG99的抗性机制，以确定大麦对目前被认为威胁世界粮食安全的高度毒力的茎锈菌小种的抗性的潜在分子途径和蛋白质相互作用。研究人员将利用遗传、分子和生化方法来回答什么机制导致抗药性，以及它们是否具有更持久的非宿主类型抗药性的特征的问题。相关基因的功能和抗性反应的时序表明，大麦中唯一已知的Ug99抗性机制，即Rpg4/Rpg5基因座，可能是多层非寄主抗性机制的残留物。因此，研究人员推测，大麦是小麦茎锈病的新近寄主，这一病理系统并不是病原菌和寄主之间古老的共同进化的结果。研究人员希望阐明参与反应的分子机制，并确定它是否是早期的非寄主类型的抗性。这些信息将填补对植物固有免疫系统有限知识的空白，还将被用来在包括小麦和大麦在内的重要谷类作物中部署更有效和更持久的抗性。该项目将用于招募和培训下一代分子植物病理学家，特别重视在科学、技术、工程和数学方面代表性不足的人。项目中使用的尖端研究工具和技术以及首席调查员的指导将为本科生和研究生提供绝佳的教育机会。

Understanding genetic resistance of crop plants against microbial pathogens is important for world food security and sustainable agricultural practices. To effectively deploy genetic resistance against important pathogens in crops we must understand the mechanisms underlying the different layers of plant innate immune systems. This project will investigate the stem rust race Ug99 resistance mechanism in barley in order to characterize the underlying molecular pathways and protein interactions mediating resistance against this highly virulent race of stem rust, currently considered a threat to world food security. The investigators will utilize genetic, molecular and biochemical approaches to answer the question of what mechanisms are responsible for resistance and if they have the characteristics of the more durable non-host type of resistance. The function of the genes involved and the timing of the resistance response indicate that the only known Ug99 resistance mechanism in barley, the rpg4/Rpg5 locus, is possibly a remnant of a multilayered non-host resistance mechanism. Thus, the investigators hypothesize that barley is a recent host of wheat stem rust and this pathosystem has not resulted from ancient co-evolution between the pathogen and the host. The investigators expect to elucidate the molecular mechanisms involved in the response and determine if it is an early non-host type of resistance. This information will fill gaps in the limited knowledge of plant innate immune systems and also be utilized to deploy more effective and durable resistance in important cereal crops including wheat and barley. The project will be utilized to recruit and train the next generation of molecular plant pathologists with special emphasis on peoples underrepresented in science, technology, engineering and mathematics. The cutting edge research tools and techniques used in the project and mentoring by the lead investigator will give undergraduate and graduate students an excellent educational opportunity.