Studies on transcriptional regulation of endogenous genes by ERF2 transcription factor in tobacco cells.

In this study, we showed that overexpression of ethylene-responsive transcription factor (ERF) 2 activated the expression of endogenous genes that have the GCC box in their promoter region, in tobacco plants. These include not only a defense-related gene, CHN50, encoding class I basic chitinase, but also a transcriptional repressor gene, ERF3. In tobacco plants constitutively expressing ERF2:glucocorticoid receptor fusion protein, treatment with dexamethazone induced a rapid increase of ERF3 mRNA and a slow increase of CHN50 mRNA. These results suggest that an antagonistic interplay of ERF2 and ERF3 is involved in the transcriptional regulation of the class I basic chitinase genes in tobacco.