VaCPK20 gene overexpression significantly increased resveratrol content and expression of stilbene synthase genes in cell cultures of Vitis amurensis Rupr

Resveratrol, a naturally occurring plant phenol, has been reported to exhibit a wide range of valuable biological and pharmacological properties. In the present investigation, we show that transformation of a Vitis amurensis Rupr. cell suspension with the gene VaCPK20 for a calcium-dependent protein kinase (CDPK) under the control of double CaMV 35S promoter increased resveratrol production in five independently transformed cell lines in 9-68 times compared with control cells. The VaCPK20-transformed calli were capable of producing 0.04-0.42 % dry wt. of resveratrol, while the control calli produced up to 0.008 % dry wt. of resveratrol Also, we characterized expression of stilbene synthase (STS) genes in the five VaCPK20-transgenic cell lines of V. amurensis. In all VaCPK20-transgenic cell lines, expression of VaSTS7 increased; while expression of VaSTS1 decreased. We suggest that transformation of V. amurensis calli with the VaCPK20 gene induced resveratrol accumulation via enhancement of expression of the VaSTS7 gene involved in resveratrol biosynthesis. The obtained data first demonstrate that overexpression of a CDPK gene resulted in increased accumulation of a stilbenoid phytoalexine in transgenic plant cells. We propose that the VaCPK20 gene could play an important role in the regulation of resveratrol biosynthesis in grape cells.