Dissection of subcellular sites of NLR function during immune signaling

抗性蛋白（r -蛋白）是植物防御病原菌的关键角色。r蛋白充当哨兵，识别病原体的入侵并启动反应以限制感染的程度。尽管我们对初始识别事件的一些细节性质有所了解，但对于r蛋白如何向植物发出防御需要部署的信号，我们知之甚少。这个项目遵循了一个有趣的观察结果，即至少有一些r蛋白，一旦被病原体激活，就会与其他蛋白质相互作用，刺激基因的表达增强，从而产生有效的免疫反应。将要进行的研究旨在加强我们对介导这些事件的分子机制的理解。研究结果可能为开发对经济上重要的植物病害具有抗性的作物品种提供新的策略。该项目将为一名博士后和一名研究生提供培训。来自代表性不足的少数民族的本科生和来自生物学本科学者计划（BUSP）的经济弱势学生将接受培训。该项目还将教授和培训一名来自加州大学戴维斯分校青年学者计划（YSP）的高中生。该项目将为一所小学到加州大学戴维斯分校的五年级学生组织一次科学实地考察。在植物和动物中，核苷酸结合域和富含亮氨酸重复序列（NLR）类细胞内免疫受体在防御病原体中起作用。尽管进行了广泛的研究，但导致NLR激活和诱导防御信号的病原体后识别事件仍然难以捉摸。研究人员最近的研究结果表明，植物NLR N与细胞核中的SPL6蛋白结合，激活了对烟草花叶病毒（TMV）的成功免疫应答。NLR rps4介导的对表达AvrRps4效应物的丁香假单胞菌的防御也需要SPL6。因此，SPL6似乎是一个保守的核成分，作为激活NLR和诱导防御基因之间的桥梁。在这个项目中，研究人员将结合遗传学、分子生物学、生物化学、基因组学、蛋白质组学和基于细胞生物学的方法来了解NLRs在免疫信号传导过程中的亚细胞动力学。SPL6在免疫信号传导过程中的精确功能将通过鉴定和表征受SPL6调控的直接靶基因来确定。此外，还将鉴定和表征SPL6相互作用蛋白。该项目的结果将通过提供nlr功能的机理见解，特别是在防御期间的空间分布和动态方面，推动免疫领域的发展。获得的知识将提高我们对植物免疫的理解，有助于利用它来帮助开发抗病原体作物并促进粮食安全。

Resistance proteins (R-proteins) are key players in a plant's defensive repertoire against pathogenic microbes. R-proteins act as sentinels that recognize incursion by a pathogen and initiate responses to limit the extent of infection. Although we understand in some detail the nature of the initial recognition event, little is known about how R-proteins signal to the plant that defenses need to be deployed. This project follows the intriguing observation that at least some R-proteins, once activated by a pathogen, interact with other proteins to stimulate enhanced expression of genes required to mount an effective immune response. The research to be carried out seeks to enhance our understanding of the molecular mechanisms that mediate these events. The results are likely to contribute new strategies for developing crop varieties that are resistant to economically significant plant diseases. The project will provide training for a postdoctoral researcher and a graduate student. Undergraduate students from under-represented minorities and economically disadvantaged students from the Biology Undergraduate Scholars Program (BUSP) will be trained. The project will also teach and train a high school student from Young Scholar Program (YSP) at UC Davis. The project will organize a science field trip for 5th grade students from an Elementary School to UC Davis.In plants and animals, the Nucleotide-binding domain and Leucine-rich Repeat (NLR) class of intracellular immune receptors function in defense against pathogens. Despite extensive research, post-pathogen recognition events leading to NLR activation and induction of defense signaling remain elusive. The investigators recent results indicate that the plant NLR N associates with the SPL6 protein in the nucleus to activate successful immune response against Tobacco Mosaic Virus (TMV). SPL6 is also required for NLR RPS4-mediated defense against Pseudomonas syringae bacteria expressing AvrRps4 effector. Therefore, SPL6 appears to be a conserved nuclear component that acts as a bridge between an activated NLR and induction of defense genes. In this project, the investigators will use a combination of genetic, molecular, biochemical, genomics, proteomics, and cell biology based approaches to understand the subcellular dynamics of NLRs during immune signaling. Precise function of SPL6 during immune signaling will be determined by identification and characterization of direct target genes that are regulated by SPL6. Also SPL6 interacting proteins will be identified and characterized. Results from the project will advance the field of immunity by providing mechanistic insights into NLRs function especially with respect to their spatial distribution and dynamics during defense. Knowledge gained will improve our understanding of plant immunity, help harness it to aid in the development of pathogen resistant crops and promote food security.