Signaling Mechanisms in Plant Innate Immunity

植物先天免疫的信号机制

• 批准号: 6868539
• 负责人: JEN SHEEN
• 金额: $ 35.44万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-12 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6868539
• 关键词: Arabidopsis; biological signal transduction; flagellin; functional /structural genomics; genetically modified plants; guanosinetriphosphatases; immune response; immunity; immunogenetics; mitogen activated protein kinase; mutant; plant genetics; plant physiology; plant proteins; protein protein interaction; transcription factor

DESCRIPTION (provided by applicant): The innate immune system is the first line of inducible defense against infectious disease. A key function of innate immunity is the detection of pathogen-associated molecular patterns (PAMPs) produced by infectious agents but not host cells and the launch of appropriate defense responses. Recent discoveries have revealed remarkable conservation in the recognition of PAMPs by leucine-rich-repeat (LRR) receptors and in signaling mechanisms of innate immune responses in plants, insects, worms, and mammals. We propose to use integrative molecular, cellular, biochemical, genomic, and genetic approaches to elucidate the signal transduction pathways induced by a well-defined bacterial flagellin peptide elicitor flg22 in the model plant Arabidopsis thaliana. The Research proposal will focus on the investigation of a MAPKKK (MEKK1) and a small GTPase (ROP11), that interact with the flg22 receptor kinase (FLS2) and mediate MAPK-dependent and MAPK-independent pathways, respectively, and converge on WRKY22/29 transcription factors in flg22 signaling. Protoplast transient assays and transgenic and mutant plants will be used for the studies. Four specific aims are: 1) Investigate the molecular mechanisms that link a specific MAPK cascade to the flg22 receptor FLS2 (a LRR receptor kinase) 2) Elucidate the function and mechanisms of ROP11-FLS2 interaction in flg22 signaling 3) Define the direct target genes of WRKY22/29 transcription factors in flg22 signaling 4) Determine the roles of the flg22 MAPK cascade, ROP11, and WRKY22/29 in plant defense responses against bacterial and fungal pathogens using transgenic and mutant plants. It has been well documented that flagellin peptide flg22 and many other pathogen-derived elicitors induce conserved signaling responses such as protein kinase activation, calcium influx, oxidative signaling, and transcriptional reprogramming. The proposed studies on the flg22 MAPK cascade, ROP11, and WRKY22/29 transcription factors that act downstream of FLS2 receptor kinase in early flg22 signaling will enhance our understanding of the molecular mechanisms underlying the early events of innate immune responses and improve our ability to manipulate durable disease resistance in plants.

描述（由申请人提供）：先天免疫系统是针对传染病的诱导性防御的第一道防线。先天免疫的一个关键功能是检测由传染源而非宿主细胞产生的病原体相关分子模式 (PAMP)，并启动适当的防御反应。最近的发现揭示了植物、昆虫、蠕虫和哺乳动物中富含亮氨酸重复序列 (LRR) 受体对 PAMP 的识别以及先天免疫反应的信号传导机制中存在显着的保守性。我们建议使用综合分子、细胞、生物化学、基因组和遗传方法来阐明模型植物拟南芥中明确的细菌鞭毛蛋白肽激发子flg22诱导的信号转导途径。该研究提案将重点研究 MAPKKK (MEKK1) 和小 GTPase (ROP11)，它们与 flg22 受体激酶 (FLS2) 相互作用，分别介导 MAPK 依赖和 MAPK 独立途径，并集中于 WRKY22/ flg22 信号转导中的 29 个转录因子。原生质体瞬时测定以及转基因和突变植物将用于研究。四个具体目标是： 1) 研究将特定 MAPK 级联与 flg22 受体 FLS2（一种 LRR 受体激酶）联系起来的分子机制 2) 阐明 ROP11-FLS2 相互作用在 flg22 信号传导中的功能和机制 3) 定义直接靶基因WRKY22/29 转录因子在 flg22 信号传导中的作用 4) 确定 flg22 MAPK 级联、ROP11 和WRKY22/29 在使用转基因和突变植物对抗细菌和真菌病原体的植物防御反应中。已有充分证据表明，鞭毛蛋白肽 flg22 和许多其他病原体衍生的激发子可诱导保守的信号转导反应，例如蛋白激酶激活、钙内流、氧化信号转导和转录重编程。对 flg22 MAPK 级联、ROP11 和 WRKY22/29 转录因子（在早期 flg22 信号传导中作用于 FLS2 受体激酶下游）的拟议研究将增强我们对先天免疫反应早期事件背后的分子机制的理解，并提高我们操纵的能力植物持久的抗病性。