Transcription Factor VvDREB2A from Improves Cold Tolerance.

Low temperatures restrict the growth of the grapevine industry. The DREB transcription factors are involved in the abiotic stress response. Here, we isolated the gene from cultivar 'Zuoyouhong' tissue culture seedlings. The full-length cDNA was 1068 bp, encoding 355 amino acids, which contained an AP2 conserved domain belonging to the AP2 family. Using transient expression in leaves of tobacco, VvDREB2A was localized to the nucleus, and it potentiated transcriptional activity in yeasts. Expression analysis revealed that was expressed in various grapevine tissues, with the highest expression in leaves. was induced by cold and the stress-signaling molecules HS, nitric oxide, and abscisic acid. Furthermore, -overexpressing was generated to analyze its function. Under cold stress, the overexpressing lines exhibited better growth and higher survival rates than the wild type. The content of oxygen free radicals, hydrogen peroxide, and malondialdehyde decreased, and antioxidant enzyme activities were enhanced. The content of raffinose family oligosaccharides (RFO) also increased in the -overexpressing lines. Moreover, the expression of cold stress-related genes (, , , and ) was also enhanced. Taken together, as a transcription factor, VvDREB2A improves plants resistance to cold stress by scavenging reactive oxygen species, increasing the RFO amount, and inducing cold stress-related gene expression levels.