Cytoplasmic and nuclear Sw‐5b NLR act both independently and synergistically to confer full host defense against tospovirus infection

作者：Hongyu Chen, Xin Qian, Xiaojiao Chen, Tongqing Yang, Mingfeng Feng, Jing Chen, Ruixiang Cheng, Hao Hong, Ying Zheng, Yuzhen Mei, Danyu Shen, Yi Xu, Min Zhu, Xin Shun Ding, Xiaorong Tao · 发表于：New Phytologist · 年份：2021 · DOI：10.1111/nph.17535 · 被引用次数：33 · 研究领域：Plant Virus Research Studies、Animal Virus Infections Studies、Virus-based gene therapy research

Plant intracellular nucleotide-binding leucine-rich repeat (NLR) receptors play critical roles in mediating host immunity to pathogen attack. We use tomato Sw-5b::tospovirus as a model system to study the specific role of the compartmentalized plant NLR in dictating host defenses against the virus at different infection steps. We demonstrated here that tomato NLR Sw-5b distributes to the cytoplasm and nucleus, respectively, to play different roles in inducing host resistances against tomato spotted wilt orthotospovirus (TSWV) infection. The cytoplasmic-enriched Sw-5b induces a strong cell death response to inhibit TSWV replication. This host response is, however, insufficient to block viral intercellular and long-distance movement. The nuclear-enriched Sw-5b triggers a host defense that weakly inhibits viral replication but strongly impedes virus intercellular and systemic movement. Furthermore, the cytoplasmic and nuclear Sw-5b act synergistically to dictate a full host defense of TSWV infection. We further demonstrated that the extended N-terminal Solanaceae domain (SD) of Sw-5b plays critical roles in cytoplasm/nucleus partitioning. Sw-5b NLR controls its cytoplasm localization. Strikingly, the SD but not coil-coil domain is crucial for Sw-5b receptor to import into the nucleus to trigger the immunity. The SD was found to interact with importins. Silencing both importin α and β expression disrupted Sw-5b nucleus import and host immunity against TSWV systemic infection. Col...