School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia.
Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Cell Host Microbe. 2019 Aug 14;26(2):193-201. doi: 10.1016/j.chom.2019.07.020.
Plant innate immunity is triggered via direct or indirect recognition of pathogen effectors by the NLR family immune receptors. Mechanistic understanding of plant NLR function has relied on structural information from individual NLR domains and inferences from studies on animal NLRs. Recent reports of the cryo-EM structures of the Arabidopsis plant immune receptor ZAR1 in monomeric inactive and transition states, as well as the active oligomeric state or the "resistosome," have afforded a quantum leap in our understanding of how plant NLRs function. In this Review, we outline the recent structural findings and examine their implications for the activation of plant immune receptors more broadly. We also discuss how NLR signaling in plants, as illustrated by the ZAR1 structure, is analogous to innate immune receptor signaling mechanisms across kingdoms, drawing particular attention to the concept of signaling by cooperative assembly formation.
植物先天免疫是通过 NLR 家族免疫受体对病原体效应子的直接或间接识别而触发的。对植物 NLR 功能的机制理解依赖于来自单个 NLR 结构域的结构信息以及对动物 NLR 研究的推断。最近报道了拟南芥植物免疫受体 ZAR1 在单体非活性和过渡态、以及活性寡聚态或“抗性体”中的 cryo-EM 结构，这使得我们对植物 NLR 如何发挥作用的理解有了质的飞跃。在这篇综述中，我们概述了最近的结构发现，并探讨了它们对更广泛地激活植物免疫受体的意义。我们还讨论了植物中的 NLR 信号转导，如图所示，与跨界的先天免疫受体信号转导机制类似，特别关注协同组装形成的信号转导概念。
