Dissection of subcellular sites of NLR function during immune signaling

免疫信号传导过程中 NLR 功能亚细胞位点的剖析

• 批准号: 1354434
• 负责人: Savithramma Dinesh-Kumar
• 金额: $ 76.4万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-15 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1354434&HistoricalAwards=false
• 关键词: Dissection; subcellular; sites; NLR; function

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.

抗性蛋白(R蛋白)在植物抵御病原微生物的防御体系中起着关键作用。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。虽然我们对最初识别事件的性质有了一些详细的了解，但对于R蛋白如何向植物发出需要部署防御系统的信号知之甚少。该项目遵循了一项耐人寻味的观察结果，即至少一些R蛋白一旦被病原体激活，就会与其他蛋白相互作用，刺激启动有效免疫反应所需基因的增强表达。即将进行的研究旨在加强我们对调节这些事件的分子机制的理解。这一结果可能为开发抗重大经济植物疾病的作物品种提供新的战略。该项目将为一名博士后研究员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生物学本科生计划(BUSP)的经济困难学生将接受培训。该项目还将教授和培训加州大学戴维斯分校青年学者计划(YSP)的一名高中生。该项目将为五年级学生组织一次科学实地考察，从一所小学到加州大学戴维斯分校。在植物和动物中，细胞内免疫受体的核苷酸结合结构域和富含亮氨酸的重复(NLR)类别具有抵御病原体的功能。尽管进行了广泛的研究，但导致NLR激活和防御信号诱导的病原体后识别事件仍然难以捉摸。研究者最近的研究结果表明，植物NLRN与细胞核中的SPL6蛋白结合，成功地激活了对烟草花叶病毒(TMV)的免疫反应。SPL6也是NLR RPS4介导的对表达AvrRps4效应的假单胞菌的防御所必需的。因此，SPL6似乎是一个保守的核成分，在激活的NLR和防御基因的诱导之间起到了桥梁作用。在这个项目中，研究人员将结合遗传学、分子、生化、基因组学、蛋白质组学和细胞生物学的方法来了解免疫信号转导过程中NLR的亚细胞动力学。SPL6在免疫信号中的确切功能将通过识别和鉴定受SPL6调控的直接靶基因来确定。此外，还将鉴定和表征SPL6相互作用的蛋白质。该项目的结果将提供对NLRs功能的机械性见解，特别是关于它们在防御期间的空间分布和动态，从而推动免疫领域的发展。所获得的知识将提高我们对植物免疫的理解，有助于利用植物免疫来帮助开发抗病原菌的作物，并促进粮食安全。