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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.)
Author(s) -
Polidoros Alexios N.,
Scandalios John G.
Publication year - 1999
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.1999.106116.x
Subject(s) - antioxidant , catalase , biochemistry , gene , gene expression , chemistry , hydrogen peroxide , glutathione , biology , microbiology and biotechnology , enzyme
The role of hydrogen peroxide (H 2 O 2 ) and various antioxidants in the regulation of expression of the three Cat and Gst1 genes of maize ( Zea mays L.) has been investigated. Low concentrations of H 2 O 2 appeared to inhibit Cat1 , Cat3 , and Gst1 gene expression, while higher doses strongly induced these genes. Time course experiments indicated that high concentrations of H 2 O 2 induced Cat1 , Cat2 , and Gst1 gene expression to higher levels, and in less time, than lower H 2 O 2 concentrations. Induction of Cat3 was superimposed on the circadian regulation of the gene. These results demonstrate a direct signaling action of H 2 O 2 in the regulation of antioxidant gene responses in maize.The effects of the antioxidant compounds N‐acetylcysteine, pyrrolidine dithiocarbamate, hydroquinone, and the electrophile antioxidant responsive element (ARE)‐inducer β ‐naphthoflavone were quite different and specific for each gene/compound/concentration combination examined. The response of each gene to each antioxidant compound tested was unique, suggesting that the ability of these compounds to affect expression of the maize Cat and Gst1 genes may not be the result of a common (antioxidant) mode of action. A putative regulatory ARE motif involved in the regulation of antioxidant and oxidative stress gene responses in mammalian systems is present in the promoter of all three maize catalase genes and we tested its ability to interact with nuclear extracts prepared from 10 days post‐imbibition senescing scutella. Protein‐DNA interactions in the ARE motif and the U2 snRNA homologous regions of the Cat1 promoter were observed, suggesting that ARE may play a role in the high induction of Cat1 in a tissue which, due to senescence, is under oxidative stress.