OsWRKY30 is a transcription activator that enhances rice resistance to the Xanthomonas oryzae pathovar oryzae

The WRKY family proteins are transcription factors involved in the regulation of plant defense response pathways. In our present study, we characterized a rice WRKY gene, OsWRKY30 that had been previously isolated through systematic expression analysis of OsWRKYs during defense responses. The endogenous expression of OsWRKY30 was found to be abolished in salicylic acid (SA)-nonaccumulating NahG transgenic rice. OsWRKY30 activates transcription in maize protoplasts and its N-terminus retains transcription activation ability in yeast. OsWRKY30-GFP fusion proteins were found to localize in the nuclei of maize protoplasts. OsWRKY30 binds to the consensus W-box motif in yeast. Overexpression of OsWRKY30 in rice upregulates an SA-responsive gene OsWRKY45, and enhances disease resistance to the Xanthomonas oryzae pathovar oryzae. These results suggest that OsWRKY30 functions as a positive regulator of rice disease resistance via an SA signaling pathway.