Phenylalanine ammonia-lyase and stilbene synthase gene expression in rolB transgenic cell cultures of Vitis amurensis

Transformation of Vitis amurensis callus culture by the plant oncogene rolB of Agrobacterium rhizogenes results in high (up to 3.15% dry wt.) levels of resveratrol in the transformed culture. The present study deals with the effect of rolB on phenylalanine ammonia-lyase (PAL) and stilbene synthase (STS) gene expression in two rolB transgenic V. amurensis callus cultures with different levels of rolB expression and resveratrol production. The total expression of PALs and STSs in rolB transgenic cultures increased 1.3-3.8 times compared with the control culture. In the rolB transgenic cultures expression of VaPAL1, VaPAL2, and six STS genes was increased, while expression of VaPAL3 and VaSTS6 was not significantly changed. These results suggest that rolB increases resveratrol production via selective enhancement of expression of individual genes from PAL and STS gene families. We propose that increase of VaPAL3, VaSTS1, and VaSTS6 transcript levels is not strongly required for high resveratrol production by rolB transgenic cell cultures.