Role of hydrogen peroxide and different classes of antioxidants in the regulation of catalase and glutathione S-transferase gene expression in maize (Zea mays L.)

gene/compound/concentration combination examined. The reThe role of hydrogen peroxide (H2O2) and various antioxidants in the regulation of expression of the three Cat and Gst1 sponse of each gene to each antioxidant compound tested was unique, suggesting that the ability of these compounds to genes of maize (Zea mays L.) has been investigated. Low concentrations of H2O2 appeared to inhibit Cat1, Cat3, and affect expression of the maize Cat and Gst1 genes may not be Gst1 gene expression, while higher doses strongly induced the result of a common (antioxidant) mode of action. A these genes. Time course experiments indicated that high putative regulatory ARE motif involved in the regulation of antioxidant and oxidative stress gene responses in mammalian concentrations of H2O2 induced Cat1, Cat2, and Gst1 gene systems is present in the promoter of all three maize catalase expression to higher levels, and in less time, than lower H2O2 concentrations. Induction of Cat3 was superimposed on the genes and we tested its ability to interact with nuclear extracts circadian regulation of the gene. These results demonstrate a prepared from 10 days post-imbibition senescing scutella. direct signaling action of H2O2 in the regulation of antioxiProtein-DNA interactions in the ARE motif and the U2 snRNA homologous regions of the Cat1 promoter were obdant gene responses in maize. The effects of the antioxidant compounds N-acetylcysteine, served, suggesting that ARE may play a role in the high induction of Cat1 in a tissue which, due to senescence, is under pyrrolidine dithiocarbamate, hydroquinone, and the electrophile antioxidant responsive element (ARE)-inducer boxidative stress. naphthoflavone were quite different and specific for each