Microarray analysis of genes that respond to γ-irradiation in Arabidopsis

To reveal the signal transduction mechanism of the response to stress in the form of active oxygen species, we used a microarray system to analyze gene expression patterns 2 or 24 h after gamma-irradiation of Arabidopsis. gamma-Irradiation induces several signal transduction and metabolite genes. By analysis of cis-elements located on the promoter region of the gamma-responsive genes, we have also found several cis-elements related to various signal transduction systems. We also analyzed the plelotropic mutant ttg1-1, which has a dramatically altered physiological response to gamma-irradiation. By comparing the gene expression patterns of wild-type (Let) and ttg1-1 mutant plants after gamma-irradiation, we identified various TTG1-regulated gamma-response genes. Analysis of the cis-elements in the promoter region of the gamma-responsive genes also revealed that the many transcription factors interacting with TTG1 protein (WD40 protein) are related to the gamma-responsive gene expression.