Genome-wide analysis of the DREB family genes and functional identification of the involvement of BrDREB2B in abiotic stress in wucai (Brassica campestris L.)

Dehydration responsive element binding protein (DREB) is a significant transcription factor class known to be implicated in abiotic stresses. In this study, we systematically conducted a genome-wide identification and expression analysis of the DREB gene family, including gene structures, evolutionary relationships, chromosome distribution, conserved domains, and expression patterns. A total of 65 DREB family gene members were identified in Chinese cabbage (Brassica rapa L.) and were classified into five subgroups based on phylogenetic analysis. Through analysis of the conserved domains of BrDREB family genes, only one exon existed in the gene structure. Through the analysis of cis-acting elements, these genes were mainly involved in hormone regulation and adversity stress. In order to identify the function of BrDREB2B, overexpressed transgenic Arabidopsis was constructed. After different stress treatments, the germination rate, root growth, survival rate, and various plant physiological indicators were measured. The results showed that transgenic Arabidopsis thaliana plants overexpressing BrDREB2B exhibited enhanced tolerance to salt, heat and drought stresses. Taken together, our results are the first to report the BrDREB2B gene response to drought and heat stresses in Chinese cabbage and provide a basis for further studies to determine the function of BrDREBs in response to abiotic stresses.