Characterization of transgenic plants derived from hairy roots of Hyoscyamus muticus

Mature plants were regenerated via protoplasts from Agrobacterium rhizogenes-transformed root cultures of Hyoscyamus muticus L., and chemical analyses were performed on 34 individual plants. The regenerated plants showed strong phenotypic differences from clone to clone as well as from the control plants. Polymerase chain reaction studies revealed that the plants exhibiting the strongest phenotypic alterations contained the rol (A, B and C) genes, whereas the plants with fewer alterations had lost them. The plants produced hyoscyamine, scopolamine and a range of different calystegins, and considerable somaclonal variation was observed. Alkaloid production in the plants transgenic for the rol genes was clearly reduced. The pattern of calystegins was similar within all the regenerated plants lacking rol genes. Among the plants with rol genes, the calystegin B i was not detectable. It seems clear that the presence of rol genes is detrimental to the alkaloid accumulation in the transgenic plants in contrast to hairy root cultures.