A class of independently evolved transcriptional repressors in plant RNA viruses facilitates viral infection and vector feeding

Significance To accomplish the infection cycle, plant viruses usually employ various pathogenic factors to inhibit host antiviral defense. Revealing pathogenic mechanisms conserved among different viruses is essential for developing broad-spectrum disease control. Here, we show that a class of independently evolved transcriptional repressors is widely present in different plant viruses. Despite the diverse sequences and different evolutionary origins, these transcriptional repressors all modulate JA signaling by inhibiting the transcriptional activation of OsMYC transcription factors, disassociating the OsMED25-OsMYC complex, and cooperating with OsJAZ to improve their transcriptional repression activity. This facilitates viral infection and enhances vector feeding. Our findings reveal key functions of the transcriptional repressors in plant viruses and shed light on the general mechanism of viral pathogenicity and vector transmission.