A salicylic acid-induced rice (Oryza sativa L.) transcription factor OsWRKY77 is involved in disease resistance of Arabidopsis thaliana

Plant WRKY transcription factors act as either positive or negative regulators of plant basal disease resistance. To comprehensively characterise the complicated functional network, we isolated OsWRKY77 from rice seedlings treated with salicylic acid. OsWRKY77 is a typical WRKY transcription factor, based on in its protein structure analysis, nuclear localisation of the fused OsWRKY77-GFP protein and gel electrophoretic mobility shift assay binding, which demonstrated that OsWRKY77 was able to bind a W-box. Transgenic Arabidopsis lines overexpressing OsWRKY77 repressed growth of Pseudomonas syringae pv. tomato DC3000 (PstDC300), and the reduced susceptibility was associated with enhanced expression of defence-related PR1, PR2 and PR5 genes. These results show that OsWRKY77 is a positive regulator of PR gene expression and basal resistance to the bacterial pathogen PstDC3000.