Abstract
OsWRKY53 is a chitin oligosaccharide elicitor-induced WRKY gene in rice. Previously we indicated that OsWRKY53 functions as a transcriptional activator, and that overexpression of OsWRKY53 in rice plants resulted in enhanced resistance to the rice blast fungus Magnaporthe oryzae. To identify direct target genes of OsWRKY53, we generated transgenic rice cells which constitutively express an OsWRKY53-HA fusion protein, and we performed ChIP-chip analysis using a custom promoter array which covers promoter regions of rice chitin elicitor-induced genes. As the result of ChIP-chip analysis, we identified several genes as the candidates of the direct target genes of OsWRKY53. These genes included transcription factors and PR protein genes. We further performed transcriptome analysis using rice cells overexpressing a dominant-nagative OsWRKY53 mutant, indicating that the expression levels of the several candidate genes decreased in the transgenic rice cells compared with vector control rice cells. Reporter gene assays to examine if the binding regions of OsWRKY53 function as elicitor-responsive cis-elements of the target genes are now in progress.
