CAREER: Dissecting the cellular pathways and signaling networks orchestrating plant defense responses and their interplay with bacterial virulence factors

职业：剖析细胞通路和信号网络，协调植物防御反应及其与细菌毒力因子的相互作用

• 批准号: 2332080
• 负责人: Clemencia Rojas
• 金额: $ 90万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2332080&HistoricalAwards=false
• 关键词: CAREER; Dissecting; cellular; pathways; signaling

Plant diseases caused by microorganisms have a significant impact on agricultural productivity and, consequently affect the availability of food and fiber for an ever-growing human population. To fight potential pathogens, plants have evolved a complex defense system that detects the presence of potential pathogens and activates multiple responses to restrict pathogen proliferation and prevent tissue damage. Some of these responses include the fortification of the cell wall and the release of molecules with antimicrobial properties. In spite of these and other defense responses diseases still occur because pathogens have also evolved multiple strategies to avoid the plant defense system. The objective of this project is to understand how plants fortify the cell wall and release antimicrobials, and how pathogens interfere with these processes. This knowledge will shed light into new approaches to control plant diseases and reduce their economic and societal impact. The research activities from this project will be used to engage undergraduate students from under-represented minorities, and will provide multi-disciplinary training for postdoctoral fellows and graduate students, who will also be mentors in the outreach activities. The plant endomembrane system is essential for pathogen recognition, and for the deployment of defense responses such as the remodeling of the cell wall and the delivery of proteins with antimicrobial properties to the extracellular milieu (apoplast). Both of these responses require protein secretion, a process that has been investigated but remains poorly understood, especially in plants, as it involves multiple and highly dynamic subcellular compartments, trafficking pathways and protein networks. Because endomembrane-mediated processes are essential in plant-pathogen interactions, these processes are also targets of pathogen's virulence factors, but the strategies that pathogens use have not been well characterized. The main objective of this project is to gain a deeper understanding into secretory pathways and signaling networks regulating plant defense responses and how these processes are targeted by virulence factors from bacterial pathogens. This project will use multi-disciplinary approaches involving live-cell imaging and proteomics technologies in combination with biological, genetic and biochemical assays to identify subcellular compartments, trafficking pathways and protein networks operating in cell wall remodeling and delivery of antimicrobial proteins to the apoplast. The project will also provide a framework to compare how bacterial pathogens with contrasting lifestyles trigger distinct sets of molecular and cellular responses, and how synergistic interactions between virulence factors from adapted bacterial pathogens subvert plant immune responses. This project is jointly funded by the Plant Biotic Interactions Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

微生物引起的植物病害对农业生产力产生重大影响，从而影响到不断增长的人口获得食物和纤维的能力。为了对抗潜在的病原体，植物进化出了一种复杂的防御系统，可以检测潜在病原体的存在，并激活多种反应来限制病原体的增殖，防止组织损伤。其中一些反应包括强化细胞壁和释放具有抗菌特性的分子。尽管有这些和其他防御反应，但疾病仍然发生，因为病原体也进化出多种策略来避开植物的防御系统。该项目的目的是了解植物如何强化细胞壁和释放抗菌素，以及病原体如何干扰这些过程。这些知识将为控制植物病害和减少其经济和社会影响的新方法提供启示。该项目的研究活动将用于吸引来自代表性不足的少数民族的本科生，并将为博士后和研究生提供多学科培训，他们也将在推广活动中担任导师。植物的膜系统对于病原体识别和防御反应的部署至关重要，如细胞壁的重塑和具有抗菌特性的蛋白质向细胞外环境（外质体）的传递。这两种反应都需要蛋白质分泌，这一过程已经被研究过，但仍然知之甚少，特别是在植物中，因为它涉及多个高度动态的亚细胞区室、运输途径和蛋白质网络。由于膜介导的过程在植物与病原体的相互作用中是必不可少的，这些过程也是病原体毒力因子的目标，但病原体使用的策略尚未得到很好的表征。该项目的主要目的是深入了解调节植物防御反应的分泌途径和信号网络，以及这些过程如何被细菌病原体的毒力因子靶向。该项目将采用多学科方法，包括活细胞成像和蛋白质组学技术，结合生物学、遗传和生化分析，以确定在细胞壁重塑和向外质体输送抗菌蛋白过程中运作的亚细胞区室、运输途径和蛋白质网络。该项目还将提供一个框架来比较不同生活方式的细菌病原体如何触发不同的分子和细胞反应，以及适应性细菌病原体的毒力因子之间的协同相互作用如何破坏植物免疫反应。该项目由植物生物相互作用计划和促进竞争研究的既定计划（EPSCoR）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。