State Key Laboratory for Quality and Safety of Argo-products, Key Laboratory of Biotechnology in Plant Protection of Agriculture and Rural Affairs and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo 315211, China.
College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Cell Rep. 2024 Oct 22;43(10):114765. doi: 10.1016/j.celrep.2024.114765. Epub 2024 Sep 21.
Nucleotide-binding leucine-rich repeat (NLR) proteins contribute widely to plant immunity by regulating defense mechanisms through the elicitation of a hypersensitive response (HR). Here, we find that TaRACK1B (the receptor for activated C-kinase 1B) regulates wheat immune response against Chinese wheat mosaic virus (CWMV) infection. TaRACK1B recruits TaSGT1 and TaHSP90 to form the TaRACK1B-TaSGT1-TaHSP90 complex. This complex is essential for maintaining NLR proteins' stability (TaRGA5-like and TaRGH1A-like) in order to control HR activation and inhibit viral infection. However, the cysteine-rich protein encoded by CWMV can disrupt TaRACK1B-TaSGT1-TaHSP90 complex formation, leading to the reduction of NLR-protein stability and suppression of HR activation, thus promoting CWMV infection. Interestingly, the 7K protein of wheat yellow mosaic virus also interferes with this antiviral immunity. Our findings show a shared viral counter-defense strategy whereby two soil-borne viruses may disrupt the TaRACK1B-TaSGT1-TaHSP90 complex, suppressing NLR-protein-mediated broad-spectrum antiviral immunity and promoting viral infection in wheat.
核苷酸结合富含亮氨酸重复（NLR）蛋白通过引发过敏反应（HR）来调节防御机制，广泛参与植物免疫。在这里，我们发现 TaRACK1B（激活 C 激酶 1B 的受体）调节小麦对中国小麦花叶病毒（CWMV）感染的免疫反应。TaRACK1B 招募 TaSGT1 和 TaHSP90 形成 TaRACK1B-TaSGT1-TaHSP90 复合物。该复合物对于维持 NLR 蛋白（TaRGA5-like 和 TaRGH1A-like）的稳定性至关重要，从而控制 HR 的激活并抑制病毒感染。然而，CWMV 编码的富含半胱氨酸的蛋白可以破坏 TaRACK1B-TaSGT1-TaHSP90 复合物的形成，导致 NLR 蛋白稳定性降低和 HR 激活受到抑制，从而促进 CWMV 感染。有趣的是，小麦黄花叶病毒的 7K 蛋白也干扰这种抗病毒免疫。我们的研究结果表明，两种土传病毒可能通过破坏 TaRACK1B-TaSGT1-TaHSP90 复合物，抑制 NLR 蛋白介导的广谱抗病毒免疫，从而促进小麦病毒感染，这揭示了一种共同的病毒防御策略。
