Effects of the rol C gene on hairy root: Induction development and tropanealkaloid production by Atropa belladonna

Two series of Atropa belladonna hairy root lines were obtained, the first o ne transformed via Agrobacterium tumefaciens harboring rol C and npt II gen es, and the other transformed with rol ABC and npt II genes. Thirteen hairy root; lines were obtained and selected on hormone-free medium. The transfo rmation was confirmed by PCR analysis, and these root lines were first exam inated for their growth rate. Then hyoscyamine and scopolamine production w as measured after 3 and 4 weeks of culture to evaluate the possible role of rol C gene in tropane alkaloid formation. The rol C gene alone played a si gnificant role in the hairy root growth rate (17-fold increase). However th is effect was much lower than that induced by the rol ABC genes together (7 5-fold increase). In contrast, the rol C gene alone was as efficient as the rol ABC genes together (mean value of total alkaloids: 0.36% dry weight, i .e., 12-fold times more than in untransformed roots) to stimulate the biosy nthesis of tropane alkaloids in A. belladonna hairy root cultures.