The gene family of dehydration responsive element-binding transcription factors in grape (Vitis vinifera): genome-wide identification and analysis, expression profiles, and involvement in abiotic stress resistance

The dehydration responsive element-binding (DREB) proteins play a critical role in plant development and abiotic stress-mediated gene expression. Therefore, they represent one of the most attractive regulons for breeding programs. However, no comprehensive summary of grapevine DREB family genes is available. During this study, 38 VvDREB members were identified from the entire grapevine genome and its expression sequence tag assembly. These were organized into the same subgroups, A1 through A6, as for Arabidopsis DREBs. The VvDREB genes were distributed in 15 out of 19 chromosomes in grapevine. Multiple sequence alignments were performed and a three-dimensional structure was created to demonstrate sequence conservation. Microarray analysis showed potential regulatory roles for VvDREBs in responses to various abiotic stresses, hormone treatments, berry ripening, exposure to light, and bud development. Cis-acting regulatory elements, such as W-box, MYB-binding site, and light-responsive elements, were the most frequently found in the putative promoter regions. Furthermore, microarray transcriptional profiling of grapevine plants that over-expressed VvDREB23 revealed 248 up-regulated and 229 down-regulated genes, with fold-changes of > 1.5 when compared with the empty vector control. Gene ontology classifications showed that different genes function in cellular glucan metabolism, lipid transport, the endomembrane system, cell wall structure, and other important metabolic and developmental processes, as well as in the regulation of molecular functions. Our report provides an overview and constitutes a foundation for further study of this VvDREB gene family. All the microarray data and transcription profiling of transgenic versus empty-vector control transformant grapevines were retrieved from the online resources.