Abstract
We isolated high-light (HL) stress-inducible genes, including a heat shock transcription factor (HsfA2) from Arabidopsis. The transcript level of HsfA2 was significantly increased under the several types of stress condition. In the HsfA2-overexpressing Arabidopsis (35S:HsfA2) plants, forty-six genes, including the stress-related genes, were highly expressed compared with those in the wild-type plants. Here we studied the gene regulation system via HsfA2 that might be associated with the response to various types of environmental stress. The transcript levels of HsfA2 target genes as well as that of HsfA2 were induced under the HL stress or the H2O2 treatment. In knockout-HsfA2 plants, the expression of HsfA2 target genes was strongly reduced under HL conditions. Furthermore, the 35S:HsfA2 plants showed increased tolerance to severe oxidative stress. Our findings indicate that HsfA2 acts as a key regulator in the induction of the defense system to several stresses.
