Abstract
Early response to oxidative stress (O3) in Arabidopsis was studied through regulation of the induction of antioxidant gene expression. For analysis of O3-induced gene expression, time course of changes in mRNA levels of selected genes, which were induced with O3-exposure, were investigated. Among the investigated genes, only AtGST3 gene was induced by O3 within 1 h. Moreover, the expression of this gene was firstly identified at 45 min after the initiation of O3-exposurre. Previous report showed that expression of AtGST3 was regulated with ethylene (ET) and salicylic acid (SA), but it's early response to O3 was not affected in ET- or SA-signaling deficient mutants. By contrast, induction of AtGST3 expression was inhibited with kinase- or Ca2+-inhibitor, suggesting that the early response of this gene requires kination or Ca2+-signaling. The involvement of a novel gene regulation system (Nrf2-Keap1 system) for the expression of AtGST3 will be demonstrated and discussed.
