A cotton dehydration responsive element binding protein functions as a transcriptional repressor of DRE-mediated gene expression.

Dehydration responsive element binding proteins (DBPs) are members of a larger family of transcription factors that are specific to plants and play an important role in enhancing plant tolerance to environmental stresses such as drought, cold, and high salinity. To gain a better understanding of this type of protein, we reported here a novel DBP protein which functioned as a repressor of transcriptional in tobacco leaf cells. GhDBP1 was preferentially localized to the nucleus of onion epidermis cells and bound specifically to DRE (core sequence, A/GCCGAC) in vitro. In addition, RNA gel-blot analysis showed that expression of the GhDBP1 gene was mainly induced under osmotic stresses conditions such as drought and high salinity. These findings suggest that GhDBP1 can function as a transcriptional repressor for DRE element-mediated gene expression and provides an important insight into the molecular adaptation mechanisms of environmental stresses in cotton plants.