Identification of an elicitor-responsive region in the promoter of a rice elicitor-responsive transcription factor gene, OsWRKY53

Abstract

WRKY proteins are a large family of transcription factors that have been suggested to have a regulatory function in the response to pathogen infection and other stresses. OsWRKY53 is a rice WRKY gene that we isolated by microarray analysis as a chitin oligosaccharide elicitor-induced gene, and overexpression of OsWRKY53 resulted in enhanced resistance to Magnaporthe grisea in rice plants. Transient gene expression assays using the firefly reporter gene were performed to identify an elicitor-responsive region in the OsWRKY53 promoter. Analysis of 5'-promoter deletions indicated that sequences between -500 and -250 contained an elicitor-responsive cis-element. In this region, there are two tandem W-box elements, which are considered to be elicitor-responsive cis-elements. Now, we are examining whether these two W-box elements function as elicitor-responsive cis-elements using site-directed mutagenesis.