A receptor-like kinase recognizes viral proteins at the trans-Golgi network/early endosome and inhibits infection in rice.

Receptor-like kinases (RLKs) reside on the cell surface and recognize apoplastic colonization by plant-infecting microbes to initiate immune responses. Whether RLKs can also recognize intracellular colonization by viruses to activate antiviral defense mechanisms in plants remains unknown. Here, we report the identification and characterization of a trans-Golgi network/early endosome (TGN/EE)-localized RLK that recognizes viral proteins and inhibits infection in rice. OsVIRK1, a cysteine-rich receptor-like kinase, promotes rice resistance to rice stripe virus (RSV), one of the most devastating viruses of rice. OsVIRK1 transcription is induced in RSV-infected rice, and its protein accumulates through autophosphorylation and redox-mediated regulation. OsVIRK1 physically interacts with the RSV coat protein (CP), a known immune elicitor, and nonstructural protein 3 (NS3), an antiviral RNA-silencing suppressor, at the TGN/EE. OsVIRK1 is required for CP-triggered defense gene expression. It phosphorylates NS3, reducing NS3 accumulation in the cytoplasm and thus repressing its activity as an RNA-silencing suppressor. Our findings suggest that OsVIRK1 recognizes viral proteins at the TGN/EE to inhibit infection by activating plant antiviral immunity and dampening viral counterdefense.