A plant NLR receptor activates auxin signaling through Aux/IAAs-ARF19 and YUC8-TIR1/AFBs to promote callose-mediated antiviral defense

作者：Tongqing Yang, Ruizhen Zhao, Ruoxin Mei, Hongmin Cui, Zixuan Ding, Yanan Wen, Qian Wu, Zhengqiang Chen, Shen Huang, Chunli Wang, Haiping Lu, Wenyu Zuo, Zhongkai Zhang, Min Zhu, Leiyun Yang, Zhengguang Zhang, Suomeng Dong, Yi Xu, Xiaorong Tao · 发表于：Science Advances · 年份：2025 · DOI：10.1126/sciadv.aea2275 · 被引用次数：1 · 研究领域：Plant Virus Research Studies、Plant Molecular Biology Research、Plant-Microbe Interactions and Immunity

Phytohormone signaling pathways are crucial for defense against pathogens mediated by pattern recognition receptors and nucleotide-binding leucine-rich repeat (NLR) immune receptors. The induction of auxin signaling by immune receptors for antiviral immunity is poorly understood despite its notable role in plant defense against viral pathogens. Here, we report that plant NLR Sw-5b initiates and amplifies auxin signaling through auxin/indole-3-acetic acid (Aux/IAAs)–ARF19 and YUC8–transport inhibitor response1/auxin-signaling F-box (TIR1/AFB) modules to promote callose-mediated antiviral defense. Upon recognizing viral effector, Sw-5b associates with and relieves repressors Aux/IAAs on transcription factor ARF19. ARF19 then activates callose synthase gene GSL5/8 to deposit callose at plasmodesmata, inhibiting viral cell-to-cell spread. Meanwhile, ARF19 activates auxin biosynthesis gene YUC8 to boost auxin production; this further amplifies callose deposition signaling via TIR1/AFB receptors and Aux/IAAs-ARF19–glucan synthase-like (GSL) module, thereby restricting the virus in localized cell death. Our findings provide valuable insights into the mechanism by which plant immune receptors induce phytohormone signaling pathways to combat pathogens.