CAREER: Regulatory Mechanisms of Pathogen-Mediated Cellular Stress Signaling in Arabidopsis: Taking Plant Molecular Biology to the Urban Garden

摘要：该项目将建立一个创新和连贯的平台，以显著提高我们对植物病原体介导的内质网（ER）胁迫的理解，培养下一代少数民族科学家，并让城市社区参与公民科学。该项目的研究范围涉及细胞应激和未折叠蛋白质积累与植物免疫系统之间的独特联系。当病原体攻击时，植物细胞增加新肽的产生，从而给内质网中的蛋白质折叠机制带来负担，并引起细胞应激。通过该项目，研究人员将了解拟南芥有效缓解这种应激反应的分子机制。从这项研究中获得的见解将通过阐明在细胞压力增加的情况下培育具有功能的作物的机制来影响农业科学——这是一个更可持续的未来的必要条件。位于阿拉巴马州伯明翰，这是一个拥有全国最多样化和贫困人口的城市（74%的非裔美国人，25%的人在贫困线以下），研究人员处于独特的地位，通过为代表性不足和社会经济地位低下的少数民族开展外展项目，促进植物生物学相关教育。研究人员将实施一个以服务和发现为基础的综合学习推广平台“OUTPACE”（推广植物病理学诊所和教育），该平台面向本科生和公民科学家：当地社区花园的低收入城市园艺家庭。OUTPACE将使学生获得基于实验室和实地的植物免疫知识，并协助社区种植者诊断植物疾病。这些努力与当前旨在加强公民参与和可持续生活以及消除城市营养不良和饥饿的区域倡议非常吻合。技术摘要：肌醇要求酶1 （IRE1）是一种高度保守的真核内质网（ER）应激传感器。虽然慢性内质网应激与后生动物免疫紊乱有关，但IRE1a在植物免疫中的作用仍然难以捉摸。最近，首席研究员在拟南芥免疫信号传导中首次建立了IRE1a与其客户端bZIP60转录因子mRNA之间的联系。在此基础上，研究人员将进一步研究内质网信号在植物免疫中的其他关键领域，并实现以下目标：1)了解生物应激依赖性IRE1a在振荡内质网胁迫条件下激活和失活的分子机制；2)阐明IRE1a功能在细胞适应或病原体介导的细胞死亡中的调控机制；3)破译IRE1a与水杨酸受体NPR1之间的反馈机制；4)新的IRE1a底物的全基因组发现和表征。为了实现这些目标，研究人员将采用成熟的和新开发的方法，包括：突变/转基因植物研究，基于植物荧光报告器的显微镜，病原体感染和细胞死亡测定，蛋白质-蛋白质相互作用和酶分析，一种新的基于酵母报告器的系统，转录谱分析和生物信息学辅助分析。

NON-TECHNICAL ABSTRACT:This project will establish an innovative and coherent platform to significantly enhance our understanding of pathogen-mediated endoplasmic reticulum (ER) stress in plants, train next-generation minority scientists, and engage an urban community in citizen science. The research scope of the project addresses a unique connection between the cellular stress and accumulation of unfolded proteins, and the plant immune system. Upon pathogen attack, plant cells increase production of new peptides, which consequently puts a burden on the protein folding machinery in the ER and causes cellular stress. Through this project, the investigators will learn about the molecular mechanisms underlying the efficient alleviation of this stress response in Arabidopsis. The insights gained from this research will impact the agricultural sciences by elucidating mechanisms to develop crop plants with the capacity to function under increased cellular stress - a necessity for a more sustainable future.Situated in Birmingham, AL, a city that has one of the most diverse and impoverished populations nationwide (74% African American, 25% below the poverty line), the investigators are in a unique position to foster plant biology-related education through outreach programs for underrepresented and socioeconomically underprivileged minorities. The investigators will implement an integrative service- and discovery-based learning outreach platform "OUTPACE" (OUTreach plant PAthology Clinic & Education) that is directed towards undergraduate students and citizen scientists: low-income urban gardening families of the local Community Gardens. OUTPACE will enable the students to acquire laboratory- and field-based knowledge of plant immunity and assist community growers in diagnosing plant diseases. These efforts are well aligned with current regional initiatives to enhance civic engagement and sustainable living, and combat urban malnutrition and hunger. TECHNICAL ABSTRACT:Inositol-Requiring Enzyme 1 (IRE1) is a highly conserved eukaryotic endoplasmic reticulum (ER) stress sensor. While chronic ER stress is linked with metazoan immune disorders, the role of IRE1a in plant immunity remains elusive. Recently, the principal investigator established the first known connection between the IRE1a and its client mRNA for the bZIP60 transcription factor in Arabidopsis immune signaling. Based on these findings, the investigators will expand their research questions to other key areas of ER signaling in plant immunity and address the following objectives: 1) Understanding the molecular mechanisms of biotic stress-dependent IRE1a activation and deactivation under oscillating ER stress conditions; 2) Elucidating the regulatory mechanisms of IRE1a functions in cellular adaptation or pathogen-mediated cell death; 3) Deciphering the feedback mechanisms between IRE1a and the salicylic acid receptor NPR1; 4) Genome-wide discovery and characterization of novel IRE1a substrates. To achieve these goals, the investigators will employ well-established and newly developed methodologies, including: mutant/transgenic plants studies, in planta fluorescent reporter-based microscopy, pathogen infections and cell death assays, protein-protein interaction and enzymatic assays, a novel yeast reporter-based system, transcriptional profiling, and bioinformatics-aided analyses.