Delineating the Roles of Dynamin-Related Proteins DRP2A and DRP2B in Regulating Plant Innate Immune Responses against Bacteria

高等生物已经发展出有效的机制来保护自己免受微生物感染。宿主的防御反应必须受到严格的调控：如果宿主不能诱导防御，微生物就会控制它们。如果反应持续被激活，宿主细胞将宝贵的资源从生长转移到防御，导致宿主生长受到惩罚。一些真核细胞利用配体诱导的内吞作用作为一种手段，从细胞表面下调受体浓度，使细胞对刺激脱敏，减弱信号反应。在这个项目中，研究者使用FLS2/鞭毛蛋白系统来描述内吞作用在调节细菌免疫中的作用。FLAGELLIN SENSITIVE 2 （FLS2）是植物细胞表面受体，可感知细菌鞭毛蛋白启动防御信号。FLS2是唯一已知的能进行配体诱导内吞作用的植物免疫受体。然而，FLS2内吞作用在调节应答和免疫中的作用尚不清楚。研究者已经确定了囊泡运输蛋白动力蛋白相关蛋白DRP2A和DRP2B是对丁香假单胞菌基础耐药性的新阳性调节因子。在本项目中，研究者结合生化、活细胞成像、蛋白质组学、病理学和遗传学方法来研究DRP2s在调节防御信号、FLS2内吞作用和对细菌免疫中的作用。除了增强对DRP2在细胞过程中的功能的了解外，该项目还可能导致增强植物先天免疫的新策略，并有助于改善食物、纤维和生物燃料的生产。该项目还为博士后研究员、研究生和本科生提供培训机会。此外，研究者小组通过开发并向小学K-5年级的学生展示动手生物实验来参与推广工作。本科生和小学生将学习收集、分析和解释数据。社会将受益于具有科学素养的公民，他们的知识背景对于在日常生活中对科学的应用做出明智的决定至关重要。

Higher organisms have developed effective mechanisms to protect themselves against microbial infection. Host defense responses must be tightly regulated: if hosts are unable to induce defenses, microbes take hold of them. If responses are continuously activated, host cells divert valuable resources from growth to defense resulting in host growth penalty. Some eukaryotic cells use ligand-induced endocytosis as a means for down-regulating receptor concentration from the cell surface to desensitize cells to stimuli and attenuate signaling responses. In this project, the investigator uses the FLS2/flagellin system to delineate roles of endocytosis in regulating immunity against bacteria. FLAGELLIN SENSITIVE 2 (FLS2) is the plant cell surface receptor that perceives bacterial flagellin to initiate defense signaling. FLS2 is the only plant immune receptor known to undergo ligand-induced endocytosis. Roles of FLS2 endocytosis in regulating responses and immunity, however, remain unknown. The investigator has identified the vesicular trafficking proteins Dynamin-Related Protein DRP2A and DRP2B as novel positive regulators of basal resistance against the bacteria Pseudomonas syringae. In this project, the investigator uses a combination of biochemical, live-cell imaging, proteomics, pathology and genetics approaches to address roles of DRP2s in regulating defense signaling, FLS2 endocytosis and immunity against bacteria. In addition to enhancing the knowledge of DRP2 functions in cellular processes, this project could lead to novel strategies for enhancing innate immunity in plants and contributing to improved food, fiber, and biofuel production. The project also provides training opportunities for a postdoctoral researcher, graduate and undergraduate students. Furthermore, the investigator's group participates in outreach efforts by developing and presenting hands-on biological experiments to K-5 elementary school students. Undergraduate and elementary students will learn to gather, analyze, and interpret data. Society will profit from scientifically literate citizens with intellectual background crucial in making educated decisions about applications for science in their everyday lives.