A viral p3a protein targets and inhibits TaDOF transcription factors to promote the expression of susceptibility genes and facilitate viral infection.

The interactions among viruses and host plants are complex and fascinating because these organisms interact with and adapt to each other continuously. Many plant transcription factors play important roles in plant growth and development and in the resistance to viral infection. To facilitate the infection of plants, some viral proteins typically target and inhibit the function of plant transcription factors. In this study, we found an interesting phenomenon wherein the p3a protein of barley yellow dwarf virus (BYDV) can interact with the zinc finger domain of the TaDOF transcription factor in wheat; the zinc finger domain of TaDOF can interact with the promoter of TaHSP70 and inhibit the transcription of the TaHSP70 gene; and p3a interacts with the TaDOF zinc finger domain through competitive binding, alleviating TaDOF zinc finger domain-mediated inhibition of the TaHSP70 promoter, thereby promoting TaHSP70 expression and promoting infection by BYDV. This study demonstrates that BYDV p3a is an immunosuppressive factor and enriches our understanding of the pathogenesis of BYDV.