Characteristics of growth and tropane alkaloid production in Hyoscyamus albus hairy roots transformed with Agrobacterium rhizogenes A4

Hairy root culture of Hyoscyamus albus was established by transformation with Agrobacterium rhizogenes strain A4. The growth and production of five tropane alkaloids were investigated under various culture conditions. Among the four basal culture media tested, Woody Plant medium was the best for growth of the hairy roots, but a high amount of tropane alkaloids was obtained with Gamborg's B5 medium. Sucrose concentration in B5 medium had little effect on the growth, while 3% sucrose was suitable for the alkaloid production. Addition of KNO3 to Woody Plant medium affected the growth, whereas the alkaloid content was not markedly improved. Supplement of some metal ions to B5 medium stimulated the alkaloid production. In particular, Cu(2+) remarkably enhanced both the growth and the alkaloid yield. The hairy roots cultured under 16 h/day light survived for more than 32 days compared with those cultured in the dark.