Effects of 5-azacytidine induced DNA demethylation on methyltransferase gene expression and resveratrol production in cell cultures of Vitis amurensis

DNA becomes methylated in vivo through the action of a specific group of enzymes known as methyltransferases or methylases. Plants are known to possess the methyltransferases (Met), chromo methyltransferases (CMT), and domainrearranged methyltransferases (DRM) methylase families, which affect cytosine methylation within different contexts. DNA methylation has been proposed to play a role in secondary plant metabolism, but there is a lack of valid data connecting these two processes. In this study, we treated control and transformed with rolB gene from Agrobacterium rhizogenes cell cultures of Vitis amurensis with the demethylation agent 5-azacytidine (azaC). The purpose of the current investigation was to study effects of induced DNA demethylation on methyltransferase gene expression in connection to resveratrol production, a naturally occurring polyphenol that has a wide range of intriguing biological properties. Using semi-quantitative and real-time PCR, we showed that rolB gene transformation of V. amurensis cells decreased Met and CMT expression, but significantly increased DRM expression. AzaC treatment of the control and the rolB-transgenic calli significantly increased expression of all methylases (excluding Met). Following 3 months of azaC treatment, we detected significantly elevated levels of rolB gene expression in the transgenic calli. In current paper, we discuss how methylase expression may influence resveratrol biosynthesis and rolB transgene expression. Effects of azaC application are discussed.