Immune responses induced by oligogalacturonides are differentially affected by AvrPto and loss of BAK1/BKK1 and PEPR1/PEPR2
Immune responses induced by oligogalacturonides are differentially affected by AvrPto and loss of BAK1/BKK1 and PEPR1/PEPR2
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DOI：
10.1111/mpp.12419
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发表时间：
2017-05-01
影响因子：
4.9
通讯作者：
De Lorenzo, Giulia
中科院分区：
文献类型：
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作者：
Gravino, Matteo;Locci, Federica;De Lorenzo, Giulia
植物具有先天免疫系统，能够限制大多数潜在病原体的入侵。在细胞表面，模式识别受体（PRRs）对微生物相关分子模式（MAMPs）和/或损伤相关分子模式（DAMPs）的识别是迅速建立有效免疫反应的第一个事件。病原体已经进化出了阻断mamp触发的免疫的效应物。丁香假单胞菌效应物AvrPto通过抑制相应受体FLS2和EFR及其共受体BAK1和BKK1的激酶功能，消除由细菌鞭毛蛋白和延伸因子Tu衍生的肽MAMPs flg22和elf18触发的免疫。低聚半乳糖醛酸酯（OGs）是一类众所周知的DAMPs，是α -1,4-链半乳糖醛酸残基的低聚物，在植物细胞壁均半乳糖醛酸的部分降解中释放。我们在这里表明，AvrPto仅影响og触发的免疫反应的一个子集，并且在这些反应中，只有一个子集受到BAK1和BKK1的伴随缺失的影响。然而，对生长素相关反应的拮抗作用不受AvrPto或BAK1/BKK1缺失的影响。这些观测结果揭示了MAMP/DAMP响应级联中前所未有的复杂性。我们还发现，另一类DAMPs及其受体pepr介导的信号系统有助于og激活免疫。我们假设OGs通过多个部分冗余的感知/转导复合物被感知，其中一些被AvrPto靶向，但不一定包括BAK1和BKK1。
Plants possess an innate immune system capable of restricting invasion by most potential pathogens. At the cell surface, the recognition of microbe-associated molecular patterns (MAMPs) and/or damage-associated molecular patterns (DAMPs) by pattern recognition receptors (PRRs) represents the first event for the prompt mounting of an effective immune response. Pathogens have evolved effectors that block MAMP-triggered immunity. The Pseudomonas syringae effector AvrPto abolishes immunity triggered by the peptide MAMPs flg22 and elf18, derived from the bacterial flagellin and elongation factor Tu, respectively, by inhibiting the kinase function of the corresponding receptors FLS2 and EFR, as well as their co-receptors BAK1 and BKK1. Oligogalacturonides (OGs), a well-known class of DAMPs, are oligomers of alpha-1,4-linked galacturonosyl residues, released on partial degradation of the plant cell wall homogalacturonan. We show here that AvrPto affects only a subset of the OG-triggered immune responses and that, among these responses, only a subset is affected by the concomitant loss of BAK1 and BKK1. However, the antagonistic effect on auxin-related responses is not affected by either AvrPto or the loss of BAK1/BKK1. These observations reveal an unprecedented complexity among the MAMP/DAMP response cascades. We also show that the signalling system mediated by Peps, another class of DAMPs, and their receptors PEPRs, contributes to OG-activated immunity. We hypothesize that OGs are sensed through multiple and partially redundant perception/transduction complexes, some targeted by AvrPto, but not necessarily comprising BAK1 and BKK1.