Resveratrol content and expression of phenylalanine ammonia-lyase and stilbene synthase genes in cell cultures of Vitis amurensis treated with coumaric acid.

The present study examines the effect of p-coumaric acid (CA), a precursor of stilbenes and isoflavonoids, on biosynthesis of resveratrol in cell cultures of Vitis amurensis. Earlier, we transformed V. amurensis with the rolB gene of Agrobacterium rhizogenes and showed increased level of resveratrol production in the rolB transgenic cell culture. We used control and the rolB-transgenic cell culture of V. amurensis as a model system in this study. CA was capable of increasing resveratrol production in the control and the rolB-transgenic cell cultures in 10.3 and 1.5 times, respectively. The CA-treated control and rolB transgenic calli produced up to 0.06% and 1.1% DW of resveratrol. Using quantitative real-time RT-PCR, we characterized the expression of phenylalanine ammonia-lyase (PAL) and stilbene synthase (STS) genes in the CA-treated control and rolB transgenic cell cultures. The expression of PAL genes remained essentially unchanged under 0.1 mM of CA, while expression of VaPAL1, VaPAL2, VaPAL3, and VaPAL5 genes was considerably decreased under 0.5 and 2 mM CA compared with the untreated cells. In the CA-treated calli, expression of VaSTS2 and VaSTS3 was increased, while expression of VaSTS5, VaSTS8, VaSTS9, and VaSTS10 was significantly decreased. These results indicate that CA increased resveratrol accumulation in V. amurensis calli via selective enhancement of expression of individual STS genes.