Abstract
The transcript levels of HSPs and several stress-related genes were highly induced in the HsfA2-overexpressing transgenic Arabidopsis plants, which showed increased tolerance to severe oxidative stress. Furthermore, the transcript level of HsfA2 of the wild-type was induced by treatment with H2O2. These findings suggest that HsfA2 is a key regulator in the induction of the defense system under oxidative stress (Plant J., 2006).
To identify signal transduction pathway involved in induction of HsfA2 under oxidative stress, we investigated effects of cycloheximide, an inhibitor of protein syhthesis, and MG132, a proteasome inhibitor, on the expression of HsfA2 in Arabidopsis T87 cells. The addition of cycloheximide inhibited the expression of HsfA2 in H2O2-treated Arabidopsis T87 cells. The addition of MG132 caused the increase in expression of HsfA2. These findings suggest that the induction of HsfA2 requires de novo protein synthesis and may be regulated by the proteasome system.
