Characterization of elicitor-responsive WRKY transcription factors involved in regulation of expressions of defense-response genes in Rice

Abstract

WRKY proteins are a large family of transcription factor that have been suggested to be involved in the responses to pathogen infection and other stresses. So far, we isolated two elicitor-responsive WRKY genes (OsWRKY53, OsWRKY71) from suspension-cultured rice cells. Using microarray analysis and quantitative RT-PCR, we revealed that several defense-related genes were upregulated in both 35S-OsWRKY53 and 35S-OsWRKY71 transgenic rice cells. We also showed by transient gene expression assays that OsWRKY71 possibly functions as a transcriptional repressor, while OsWRKY53 was suggested to function as a transcriptional activator. These results suggest that OsWRKY53 and OsWRKY71 cooperatively function in the regulation of expression of these defense-related genes in a unique manner. Identification of a repressor domain of OsWRKY71 is also now underway.