VlbZIP30 of grapevine functions in dehydration tolerance via the abscisic acid core signaling pathway.

Drought stress limits the growth and development of grapevines, thereby reducing productivity, but the mechanisms by which grapevines respond to drought stress remain largely uncharacterized. Here, we characterized a group A bZIP gene from "Kyoho" grapevine, , which was shown to be induced by abscisic acid (ABA) and dehydration stress. Overexpression of in transgenic enhanced dehydration tolerance. Transcriptome analysis revealed that a major proportion of ABA-responsive and/or drought-responsive genes are transcriptionally regulated by during ABA or mannitol treatment at the cotyledon greening stage. We identified an G-box motif (CACGTG) and a potential grapevine G-box motif (MCACGTGK) in the promoters of the 39 selected genes upregulated in the transgenic plants and in the 35 grapevine homologs, respectively. Subsequently, using two grapevine-related databases, we found that 74% (23/31) and 84% (21/25) of the detected grapevine genes were significantly upregulated by ABA and drought stress, respectively, suggesting that these genes are involved in ABA or dehydration stress and may be regulated by in grapevine. We propose that functions as a positive regulator of dehydration-responsive signaling in the ABA core signaling pathway.