Isolation And Characterization Of Two Elicitor-responsive Genes Encoding WRKY DNA-binding Proteins From Rice

Abstract

WRKY proteins are a large family of transcription factors that specifically bind to the W-box. Many WRKY proteins have been suggested to have a regulatory function in the response to pathogen infection and other stresses. In suspension-cultured rice cells, diterpenoid phytoalexins are produced in response to exogenously applied elicitors such as chitin oligomers and cerebrosides from the pathogen Magnaporthe grisea. By means of microarray analysis, we isolated two rice WRKY genes, OsSPF1 and OsABF2, that were induced with a chitin elicitor, N-acetylchitooctaose, in suspension-cultured rice cells. OsSPF1 belongs to group I WRKY proteins, and OsABF2 belongs to group II. Expression of the OsSPF1 and OsABF2 genes were induced by cerebroside B as well as N-acetylchitooctaose in suspension-cultured rice cells. The expression of these genes were induced in rice plants infected with M. grisea. These results strongly suggested that OsSPF1 and OsABF2 were involved in defence-gene regulation of pathogen-attacked rice.