Molecular analysis of apoplastic effector-mediated suppression of PTI signaling

通过膜结合模式识别受体（PRRs）介导的植物先天免疫有助于保护免受微生物感染。然而，适应宿主的植物病原真菌和卵菌已经进化出操纵植物细胞外功能以建立感染的质外体效应子。最近，我们发现了一个保守的效应蛋白SCP 8大丽轮枝菌，真菌病原体具有广泛的主机范围。SCP 8通过激活LRR-RK和LRR-RP型PRR抑制拟南芥中的一些免疫相关防御。在这里，我们建议确定SCP 8内的结构基序，其免疫抑制活性所需的。我们进一步建议采用先进的蛋白质-蛋白质相互作用技术和正向遗传筛选，以确定推定的SCP 8相互作用的植物蛋白参与SCP 8介导的免疫抑制。我们的工作旨在获得一个质外体真菌效应如何操纵植物宿主免疫激活的分子理解，通过干扰植物免疫系统的组成部分，共享之间的某些，但不是所有的PRR。这项工作可能证明了利用微生物效应器破译植物免疫信号转导级联的潜力。

Plant innate immunity mediated through membrane-bound pattern recognition receptors (PRRs) is instrumental to protection against microbial infections. However, host-adapted plant pathogenic fungi and oomycetes have evolved apoplastic effectors that manipulate plant extracellular functions in order to establish infection. Recently, we identified a conserved effector protein SCP8 from Verticillium dahliae, a fungal pathogen with a broad host range. SCP8 suppresses some immunity-associated defenses in Arabidopsis mediated through activation of LRR-RK and LRR-RP-type PRRs. Here, we propose to identify structural motifs within SCP8 that are required for its immunosuppressive activity. We further propose to employ sophisticated protein-protein interaction technologies and forward genetic screens to identify putative SCP8-interacting plant proteins involved in SCP8-mediated immune suppression. Our work aims at gaining a molecular understanding of how an apoplastic fungal effector may manipulate plant host immune activation through interference with components of the plant immune system that are shared among certain, but not all PRRs. This work may demonstrate the potential of using microbial effectors to decipher plant immune signal transduction cascades.