Conserved fungal effector suppresses PAMP-triggered immunity by targeting plant immune kinases
Conserved fungal effector suppresses PAMP-triggered immunity by targeting plant immune kinases
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DOI：
10.1073/pnas.1807297116
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发表时间：
2019-01-08
影响因子：
11.1
通讯作者：
Takano, Yoshitaka
中科院分区：
文献类型：
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作者：
Irieda, Hiroki;Inoue, Yoshihiro;Takano, Yoshitaka
植物病原体优化了自己的效应器集以适应宿主。然而，某些被视为核心效应子的效应子在各种病原体中是保守的，因此可能在病原体毒力中发挥重要而共同的作用。我们在此报告，广泛分布的真菌效应子NIS1以宿主免疫成分为目标，这些成分传递来自植物中模式识别受体（PRR）的信号。 NIS1 来自两种炭疽菌属。抑制本塞姆氏烟草中的过敏反应和氧化爆发，这两种反应都是由病原体衍生分子诱导的。稻瘟病菌 NIS1 也抑制了这两种防御反应，尽管这种病原体可能通过从担子菌门水平转移获得 NIS1 基因。有趣的是，根内生菌 Colletotrichum tofieldiae 也拥有 NIS1 同源物，可以抑制本塞姆氏烟草的氧化爆发。我们发现多种病原体的 NIS1 通常与 PRR 相关激酶 BAK1 和 BIK1 相互作用，从而抑制它们的激酶活性和 BIK1-NADPH 氧化酶相互作用。此外，拟南芥中 NIS1 靶向蛋白（即 BAK1 和 BIK1）的突变也会导致对炭疽菌真菌的免疫力降低。最后，缺乏NIS1的米霉对其宿主水稻和大麦的毒力显着降低。因此，我们的研究表明，多种丝状真菌维持并利用核心效应子 NIS1 在宿主植物中建立感染，并且通过靶向保守的中央 PRR 相关激酶（已知这些激酶也被细菌效应子靶向），或许还有有益的相互作用。
Plant pathogens have optimized their own effector sets to adapt to their hosts. However, certain effectors, regarded as core effectors, are conserved among various pathogens, and may therefore play an important and common role in pathogen virulence. We report here that the widely distributed fungal effector NIS1 targets host immune components that transmit signaling from pattern recognition receptors (PRRs) in plants. NIS1 from two Colletotrichum spp. suppressed the hypersensitive response and oxidative burst, both of which are induced by pathogen-derived molecules, in Nicotiana benthamiana. Magnaporthe oryzae NIS1 also suppressed the two defense responses, although this pathogen likely acquired the NIS1 gene via horizontal transfer from Basidiomycota. Interestingly, the root endophyte Colletotrichum tofieldiae also possesses a NIS1 homolog that can suppress the oxidative burst in N. benthamiana. We show that NIS1 of multiple pathogens commonly interacts with the PRR-associated kinases BAK1 and BIK1, thereby inhibiting their kinase activities and the BIK1-NADPH oxidase interaction. Furthermore, mutations in the NIS1-targeting proteins, i.e., BAK1 and BIK1, in Arabidopsis thaliana also resulted in reduced immunity to Colletotrichum fungi. Finally, M. oryzae lacking NIS1 displayed significantly reduced virulence on rice and barley, its hosts. Our study therefore reveals that a broad range of filamentous fungi maintain and utilize the core effector NIS1 to establish infection in their host plants and perhaps also beneficial interactions, by targeting conserved and central PRR-associated kinases that are also known to be targeted by bacterial effectors.