Two TGA Transcription Factor Members from Hyper-Susceptible Soybean Exhibiting Significant Basal Resistance to .

TGA transcription factors (TFs) exhibit basal resistance in , but susceptibility to a pathogen attack in tomatoes; however, their roles in soybean () to (SMV) are unknown. In this study, 27 genes were isolated from a SMV hyper-susceptible soybean , designated ~, which were clustered into seven phylogenetic groups. The expression profiles of showed that the highly expressed genes were mainly in Groups I, II, and VII under non-induction conditions, while out of the 27 , 19 responded to SMV-induction. Interestingly, in further transient -SMV pathosystem assay, all the 19 overexpressed did not promote SMV infection in inoculated leaves, but they exhibited basal resistance except one without function. Among the 18 functional ones, GmTGA8 and GmTGA19, with similar motif distribution, nuclear localization sequence and interaction proteins, showed a rapid response to SMV infection and performed better than the others in inhibiting SMV multiplication. This finding suggested that GmTGA TFs may support basal resistance to SMV even from a hyper-susceptible source. What the mechanism of the genes (, , etc.) with basal resistance to SMV is and what their potential for the future improvement of resistance to SMV in soybeans is, are to be explored.