Identification and molecular characterization of microbe-derived PAMPs and their corresponding perception systems in Arabidopsis

PAMP触发的免疫(PTI)是植物的主要或基础免疫反应。PTI的激活是基于植物模式识别受体对微生物表面不变模式的识别。尽管在不同的植物物种中发现了一些可以触发免疫反应的微生物表面成分，但植物的非自我识别能力有望达到远远超出现有知识的水平。在以前的工作中，我们已经在分离的青枯雷尔氏菌细胞中发现了能够在拟南芥中触发免疫相关反应的多肽片段。这些多肽将被纯化成均一种，并用于鉴定相应的平台模式识别受体。革兰氏阳性和革兰氏阴性细菌衍生的肽聚糖(PGN)在拟南芥中诱导PTI反应。LYM3是一种带有两个异位LysM结构域的拟南芥质膜蛋白，与植物对细菌侵染的PGN结合、PGN敏感性和植物免疫有关。LYM3是一个小蛋白家族的成员，由另外两个成员(LYM1、LYM2)组成。我们的目的是确定LYM1和LYM2蛋白在植物对PGN的感知和植物对微生物感染的免疫中的作用。

PAMP-triggered immunity (PTI) constitutes the primary or basal plant immune response. Activation of PTI is based upon the recognition of invariant patterns of microbial surfaces by plant pattern recognition receptors. Despite the identification of some microbial surface components that trigger immune responses in various plant species, non-self recognition capacities of plants are expected to reach substantially beyond current knowledge. In previous work, we have identified in fractionated Ralstonia solanacearum cell extracts peptidic fragments that trigger immunity-associated responses in Arabidopsis. These peptides will be purified to homogeneity and used to identify the corresponding plattern pattern recognition receptor.Gram-positive and Gram-negative bacteria-derived peptidoglycans (PGN) induce PTI responses in Arabidopsis. LYM3, an Arabidopsis plasma membrane protein that carries two ectopic LysM domains, has been implicated in PGN binding, PGN sensitivity and plant immunity to bacterial infection. LYM3 is a member of a small protein family comprising two additional members (LYM1, LYM2). We aim at characterizing the contribution of LYM1 and LYM2 proteins to PGN perception and to plant immunity to microbial infection.