A novel wheat NAC transcription factor,Ta NAC30, negatively regulates resistance of wheat to stripe rust

NAC transcription factors are widespread in the plant kingdom and play essential roles in the transcriptional regulation of defense responses. In this study, we isolated a novel NAC transcription factor gene, Ta NAC30,from a c DNA library constructed from wheat(Triticum aestivum) plants inoculated with the stripe rust pathogen Puccinia striiformis f. sp. tritici(Pst). Ta NAC30contains a typical NAM domain and localizes to the nucleus. Yeast one-hybrid assays revealed that Ta NAC30exhibits transcriptional activity and that its C-terminus is necessary for the activation of transcription. Expression of Ta NAC30increased when host plants were infected with a virulent race(CYR31) of the rust fungus Pst. Silencing of Ta NAC30byvirus-induced gene silencing inhibited colonization of the virulent Pst isolate CYR31. Moreover, detailed histological analyses showed that silencing of Ta NAC30enhanced resistance to Pst by inducing a significant increase in the accumulation of H2O2. Finally, we overexpressed Ta NAC30in fission yeast and determined that cell viability was severely reduced in Ta NAC30-transformed cells grown on medium containing H2O2. These results suggest that Ta NAC30negatively regulates plant resistance in a compatible wheat-Pst interaction.