Plant intracellular nucleotide-binding leucine-rich repeat receptors (NLRs) detect pathogen effectors to trigger immune responses¹. Indirect recognition of a pathogen effector by the dicotyledonous Arabidopsis thaliana coiled-coil domain containing NLR (CNL) ZAR1 induces the formation of a large hetero-oligomeric protein complex, termed the ZAR1 resistosome, which functions as a calcium channel required for ZAR1-mediated immunity^2,3,4. Whether the resistosome and channel activities are conserved among plant CNLs remains unknown. Here we report the cryo-electron microscopy structure of the wheat CNL Sr35⁵ in complex with the effector AvrSr35⁶ of the wheat stem rust pathogen. Direct effector binding to the leucine-rich repeats of Sr35 results in the formation of a pentameric Sr35–AvrSr35 complex, which we term the Sr35 resistosome. Wheat Sr35 and Arabidopsis ZAR1 resistosomes bear striking structural similarities, including an arginine cluster in the leucine-rich repeats domain not previously recognized as conserved, which co-occurs and forms intramolecular interactions with the 'EDVID' motif in the coiled-coil domain. Electrophysiological measurements show that the Sr35 resistosome exhibits non-selective cation channel activity. These structural insights allowed us to generate new variants of closely related wheat and barley orphan NLRs that recognize AvrSr35. Our data support the evolutionary conservation of CNL resistosomes in plants and demonstrate proof of principle for structure-based engineering of NLRs for crop improvement.

植物细胞内核苷酸结合富含亮氨酸的重复受体 (NLR) 检测病原体效应子以触发免疫反应¹ 。含有 NLR (CNL) ZAR1 的双子叶植物拟南芥卷曲螺旋结构域间接识别病原体效应子，诱导形成大型异源寡聚蛋白复合物，称为 ZAR1 抗性体，其功能作为 ZAR1 介导的免疫所需的钙通道^2,3,4 。植物 CNL 中的抗性体和通道活性是否保守仍不清楚。在这里，我们报道了小麦 CNL Sr35 ⁵与小麦茎锈病病原体效应子 AvrSr35 ⁶复合物的冷冻电子显微镜结构。效应子直接与富含亮氨酸的 Sr35 重复序列结合，导致形成五聚体 Sr35-AvrSr35 复合物，我们将其称为 Sr35 抗性体。小麦 Sr35 和拟南芥ZAR1 抗性体具有惊人的结构相似性，包括富含亮氨酸的重复结构域中的精氨酸簇，以前未被认为是保守的，它与卷曲螺旋结构域中的“EDVID”基序共存并形成分子内相互作用。电生理学测量表明，Sr35 抗性体表现出非选择性阳离子通道活性。这些结构见解使我们能够生成密切相关的小麦和大麦孤儿 NLR 的新变体，这些变体可识别 AvrSr35。我们的数据支持植物中 CNL 抗性体的进化保守性，并证明了基于结构的 NLR 工程用于作物改良的原理证明。