To investigate the role of V2 encoded by TbCSV in virus infection, V2 coding sequence was inserted into and heteroexpressed by potato virus X. The recombinant infectious clone named PVX-V2 was agroinfiltrated into N. benthamiana at the six-leaf stage, and the hypersensitive response began to emerge on the infiltrated leaves at 5 days postinoculation (dpi) (data not shown). This evidence concerns the gene TRGV9 and viral infectious disease.