Transcriptional analysis of Dehydrin1 genes responsive to dehydrating stress in grapevines

Abstract

Dehydrins (DHNs) are proteins that are induced under dehydrating stress conditions such as drought, cold, and salinity. We investigated the expression of the DHN1 genes over time after drought treatment for 14 days and subsequent rehydration in the Korean native species, Vitis flexuosa, main cultivars 'Campbell Early' (Vitis spp.) and 'Tamnara' (Vitis spp.). Two highly homologous dehydrins, DHN1a and DHN1b, were isolated from 'Campbell Early' and 'Tamnara' grapevines, but only DHN1a cDNA was cloned from V. flexuosa leaves. Amino acid sequences of DHN1 deduced from five cDNAs of DHN1a/b from three grapevines were of the YSK2-type having the Y-, S-, and K-domain. Analysis of expression using quantitative real-time polymerase chain reaction and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) revealed that expression of the DHN1a and DHN1b genes was induced earlier in V. flexuosa under drought stress conditions than in 'Campbell Early' and 'Tamnara'. During drought stress, a large amount of DHN1a and DHN1b was continuously expressed. V. flexuosa could be a resource in stress-tolerant grape breeding for enhancing drought tolerance.