Abstract
An Arabidopsis transcription factor gene, DREB2A, is known to play an important role in environmental stress responses. DREB2B was isolated as a DREB2A homologue with highest similarity. But function of DREB2B under environmental stress conditions was still unclear.
Expression analysis using qRT-PCR revealed increased expression levels of DREB2B under drought, heat and high salinity stress conditions. Transient assay using GFP-fused protein indicated that DREB2B protein localized in nuclei of plant cells. Phenotypic analysis of DREB2B overexpressors and T-DNA tagged mutants did not show any morphological difference compared to wild-type plants. Microarray analysis using DREB2B overexpressors showed that 41 genes were upregulated in plants. Most of these were related to sugar metabolisms. Thermotolerance test revealed improved tolerance of overexpressors. DREB2B possesses the sequence with high homology to negative regulatory domain of DREB2A. We are currently analyzing the activity of this regulatory domain.
