Role of organelle dynamics and retrograde signaling during plant innate immunity

细胞器动力学和逆行信号在植物先天免疫过程中的作用

• 批准号: 10380113
• 负责人: Jeffrey L Caplan
• 金额: $ 46.42万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10380113
• 关键词: Actins; Affect; Animals; Apoptosis; Automobile Driving; Bacteria; Binding; Biological; Biological Models; Cell Death; Cell Nucleus; Cell membrane; Cell surface; Cells; Cellular biology; Chloroplasts; Communicable Diseases; Communication; Cytoskeleton; Cytosol; Development; Flagellin; Generations; Genetic; Genetic Screening; Goals; Hormones; Hydrogen; Hydrogen Peroxide; Hypersensitivity; Image Analysis; Immune; Immune response; Immune signaling; Immunity; Immunologic Receptors; Infection; Innate Immune Response; Kinesin; Label; Leucine-Rich Repeat; MAP Kinase Gene; Measures; Microfilaments; Microtubules; Mitochondria; Modeling; Molecular; Morphology; Motor; Movement; NADPH Oxidase; Nanotubes; Natural Immunity; Nuclear; Nucleotides; Organelles; Pattern; Pattern recognition receptor; Peroxides; Phosphotransferases; Plants; Play; Positioning Attribute; Process; Proteins; Proteomics; Pseudomonas syringae; RIPK1 gene; Reactive Oxygen Species; Regulation; Research; Role; Salicylic Acids; Signal Transduction; Source; System; Testing; Tubular formation; Vertebrates; Virulence; base; extracellular; forward genetics; genetic approach; insight; mutant; novel; organelle movement; pathogen; prevent; receptor; recruit; response; screening; superoxide-generating NADPH oxidase

1 Project Summary 2 This project focuses on the chloroplast as central player in the generation of immune signals and the 3 regulation of programmed cell death (PCD) required for innate immune responses against pathogen infection. 4 Although mitochondria play a central role during mammalian PCD, emerging evidence suggests that in plants 5 chloroplasts have a critical function in executing localized PCD that limits pathogen spread. Chloroplasts in 6 addition to being involved in the generation of immune signals, such as reactive oxygen species (ROS) and the 7 defense hormone salicylic acid (SA), also participate directly in the recognition of pathogens. Interestingly, 8 chloroplasts dynamically change their morphology during immune responses and send out stroma-filled tubular 9 projections called stromules. These induced stromules use the cytoskeleton to extend and then anchor to the 10 nucleus, which facilitate perinuclear clustering of chloroplasts and transport of chloroplast-generated hydrogen 11 peroxide (H2O2) ROS and defense proteins to the nucleus. The overall goal of this application is to use a 12 combination of novel cell biology, genetics, proteomics and computational approaches to unravel the 13 mechanistic basis of stromule formation and their role in driving perinuclear chloroplast clustering and 14 subsequent release of retrograde immune signals from chloroplasts to nuclei. Specifically, Aim 1 will identify 15 and characterize proteins required for stromule formation and stromule-directed chloroplast movement. This 16 includes the kinesin motor required for extension and proteins associated with the outer envelope of stromules 17 that may drive stromule initiation or regulation. An unbiased forward genetic screen will be conducted to 18 identify other stromule specific components. Aim 2 will investigate immune signals required for stromule 19 induction and the release of H2O2 as a specific retrograded chloroplast signal. The role of stromules in 20 amplification of immune signaling consisting of SA and H2O2 signaling will be examined. The relationship of 21 different H2O2 sources, organelle movement and PCD during immune responses will be studied to determine 22 how H2O2 propagates extracellularly to intracellular sources to regulate innate immune responses. The function 23 of stromules and chloroplast positioning during H2O2 signal propagation will be examined using the stromule- 24 specific mutants characterized in Aim 1. Aim 3 will focus on how pathogen effectors affect stromules, 25 organelle, and cytoskeleton dynamics as a virulence strategy. In addition, mechanistic basis of how three 26 effectors disrupt stromules and organelle dynamics will be determined. Understanding the role of different 27 organelles during PCD and innate immunity will provide a unified mechanistic basis of cell death and cell 28 survival process that occur in response to infectious pathogens. The results from our model systems will 29 impact broadly on understanding of organelle-to-nuclear communication that influence innate immunity against 30 infectious diseases.

1 项目概要 2 该项目重点关注叶绿体作为免疫信号生成的核心角色以及 3 对病原体感染的先天免疫反应所需的程序性细胞死亡（PCD）的调节。 4 尽管线粒体在哺乳动物 PCD 过程中发挥着核心作用，但新出现的证据表明，在植物中 5 叶绿体在执行限制病原体传播的局部 PCD 方面具有关键功能。叶绿体在 6 除了参与免疫信号的产生，例如活性氧 (ROS) 和 7种防御激素水杨酸（SA），也直接参与病原体的识别。有趣的是， 8 叶绿体在免疫反应过程中动态改变其形态并发出充满基质的管状结构 9 个投影称为 stromules。这些诱导的基质使用细胞骨架延伸，然后锚定到 10个核，促进叶绿体的核周聚集和叶绿体产生的氢的运输 11 过氧化物 (H2O2) ROS 和细胞核的防御蛋白。该应用程序的总体目标是使用 12 结合新颖的细胞生物学、遗传学、蛋白质组学和计算方法来解开 13 基质形成的机制基础及其在驱动核周叶绿体聚集和驱动中的作用 14 随后从叶绿体向细胞核释放逆行免疫信号。具体来说，目标 1 将确定 15 并表征了基质形成和基质定向叶绿体运动所需的蛋白质。这 16 包括延伸所需的驱动蛋白运动和与基质外膜相关的蛋白质 17 可能驱动基质的启动或调节。将进行无偏见的前向遗传筛选 18 确定其他 structule 特定组件。目标 2 将研究 structule 所需的免疫信号 19 诱导和释放 H2O2 作为特定的退化叶绿体信号。斯特鲁斯的作用 将检查由SA和H2O2信号组成的20个免疫信号放大。的关系 将研究 21 种不同的 H2O2 来源、免疫反应期间的细胞器运动和 PCD，以确定 22 H2O2 如何从细胞外传播到细胞内来源以调节先天免疫反应。功能 23 H2O2 信号传播期间的 stromule 和叶绿体定位将使用 stromule- 进行检查 目标 1 中描述了 24 个特定突变体。目标 3 将重点关注病原体效应子如何影响基质， 25 细胞器和细胞骨架动力学作为毒力策略。此外，三者的机制基础如何 26 个效应器会破坏基质，并确定细胞器动力学。了解不同角色的作用 PCD过程中的27个细胞器和先天免疫将为细胞死亡和细胞死亡提供统一的机制基础 28 针对传染性病原体而发生的生存过程。我们的模型系统的结果将 29 对影响先天免疫的细胞器到核通讯的理解产生广泛影响 30种传染病。