Transgenic Expression of an Ethylene Responsive Element Binding Protein of Capsicum annuum (CaEREBP-C4) in Tobacco Confers Cold Tolerance

Abstract

EREBP, ethylene responsive element binding protein, plays a role in plant tolerance to abiotic stresses such as low temperatures, drought and high salinity. We previously used cDNA microarrays and northern blot analysis to determine the mechanisms responsible for those underlying defenses. These analyses led to identification of CaEREBP-C4, a gene that encodes the ethylene responsive element binding protein from hot pepper (Capsicum annuum). In that study, we demonstrated that the CaEREBP-C4 gene was strongly induced by cold stress. Here, we used Ti-plasmid and Agrobacterium-mediated transformation to engineer CaEREBP-C4 under control of the CaMV 35S promoter for constitutive expression in transgenic tobacco. The resultant CaEREBP-C4 transgenic plants exhibited significantly increased tolerance to low temperature. Moreover, the transgenic plants that showed strong cold tolerance also had greater tolerance to drought stress. In addition, none of the CaEREBP-C4 transgenic plants showed visible phenotypic alteration when compared to wild type plants. Taken together, these results suggest that CaEREBP-C4 plays a biological role in conferring plant abiotic stress tolerance.