Sung Yi-Chang, Li Yinghui, Bernasconi Zoe, Baik Suji, Asuke Soichiro, Keller Beat, Fahima Tzion, Coaker Gitta
Department of Plant Pathology, University of California, Davis, CA, USA.
Institute of Evolution and the Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel.
Nat Genet. 2025 May;57(5):1238-1249. doi: 10.1038/s41588-025-02162-w. Epub 2025 Apr 14.
Plants have intricate innate immune receptors that detect pathogens. Research has intensely focused on two receptor classes recognizing external and internal threats. Recent research has identified a class of disease-resistance proteins called tandem kinase proteins (TKPs). We investigated RWT4, a wheat TKP that confers resistance to the devastating fungal pathogen Magnaporthe oryzae. We established a rice protoplast system, revealing RWT4 specifically recognizes the AvrPWT4 effector, leading to the transcription of defense genes and inducing cell death. RWT4 possesses both kinase and pseudokinase domains, with its kinase activity essential for defense. RWT4 directly interacts with and transphosphorylates AvrPWT4. Biolayer interferometry revealed both RWT4 kinase and pseudokinase regions bind the effector. Sequence similarity and structural modeling revealed a partial kinase duplication in RWT4's kinase region as critical for effector interaction and defense activation. Collectively, these findings demonstrate that TKPs can directly bind a recognized effector, leading to downstream defense activation.
植物具有复杂的先天免疫受体来检测病原体。研究主要集中在两类识别外部和内部威胁的受体上。最近的研究发现了一类称为串联激酶蛋白（TKP）的抗病蛋白。我们研究了RWT4，一种赋予小麦对毁灭性真菌病原体稻瘟病菌抗性的TKP。我们建立了一个水稻原生质体系统，发现RWT4特异性识别AvrPWT4效应子，导致防御基因转录并诱导细胞死亡。RWT4同时具有激酶和假激酶结构域，其激酶活性对防御至关重要。RWT4直接与AvrPWT4相互作用并使其发生转磷酸化。生物膜干涉术显示RWT4的激酶和假激酶区域均能结合效应子。序列相似性和结构建模表明，RWT4激酶区域中的部分激酶重复对于效应子相互作用和防御激活至关重要。这些发现共同表明，TKP可以直接结合已识别的效应子，从而导致下游防御激活。
