Transformation of Catalpa ovata by Agrobacterium rhizogenes and phenylethanoid glycosides production in transformed root cultures.

Transformed root cultures of Catalpa ovata were established following shoots infection with four agropine strains of Agrobacterium rhizogenes. Frequency of root formation was dependent on the bacterial strain and the presence of acetosyringone in the incubation medium. It is the first report concerning the possibility of transforming Catalpa ovata by A. rhizogenes. Both transformed and untransformed root cultures of C. ovata were studied for their growth and phenylethanoid glycoside production. As with the roots of intact plants, cis- and trans-verbascoside as well as martynoside were produced in transformed and untransformed root cultures of C. ovata. In hairy roots, total (cis + trans) verbascoside production could be stimulated up to three-fold of that of roots of 6-month-old plants grown in a greenhouse, by using an appropriate root line cultured in liquid 1/2 B5 Gamborg medium containing indole-3-butyric acid (0.1 mg/l) in the dark but not light conditions. Transformed and untransformed root cultures of C. ovata were also found to have 10 times higher martynoside production than roots of intact plants.