Transcript profiling of native Korean grapevine species Vitis flexuosa exposed to dehydration and rehydration treatment

Vitis flexuosa , a native Korean wild grapevine species, is more tolerant to abiotic stress than cultivated grapevines, but little is known about the mechanism underlying this tolerance. To better characterize the responses of V. flexuosa to drought stress and subsequent rehydration, we treated V. flexuosathe plants with four stress conditions: short- and long-term dehydration, rehydration immediately after long-term drought, and long-term rehydration after long-term drought. We examined gene expression profiles in response to these treatments using whole-genome microarray analysis at 12X coverage (using the NimbleGen protocol). We identified a 5,964 genes that were differentially expressed between the stress treatments and the well-watered control. Gene ontology analysis showed that most of the differentially expressed genes (DEGs), regardless of treatment, participate in the metabolism of proteins or phosphatecontaining compounds and function in the binding of metal ions, as kinases, or as phosphotransferases. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that genes involved in secondary metabolite biosynthesis were downregulated during dehydration but upregulated during rehydration. Among the DEGs encoding transcription factors, genes in the MYB family were the most common differentially genes in all treatment groups. The NAC family was the second most common group during dehydration, while the AP2/ERF family was the second most common during rehydration. These results will help elucidate the mechanisms underlying the response of V. flexuosa to drought stress and will be valuable for breeding drought-tolerant grapevines.