Effects of chemicals on alkaloid production by transformed roots of belladonna

The growth and tropane content in transformed root cultures of Atropa belladonna (strain M8) grown in 300 ml flasks were studied. After one month in culture, the biomass of the transformed roots increased 15 times and reached 5 g dry wt l(-1); the alkaloid contents were 0.7% for (-)-hyoscyamine, 0.1% for 6 beta-hydroxyhyoscyamine, 0.02% for scopolamine and 0.02% for littorine. During the culture period, no alkaloid could be detected in the medium. Seven chemicals were individually added to 18-day-old cultures. Glutathione (5 mM), chitin (0.1%), chitosan (0.1%) or yeast extract (0.1%) had no effect on the release of alkaloids into the medium. However, treatment with 5 mM H2O2 induced a transient release of tropane alkaloids from transformed roots and the maximum amount of alkaloids in the medium was ca 0.35 mg per flask (10% of alkaloid contained in tissues); tissue viability was still preserved. Cu2+ and Cd2+ (5 mM) also improved the excretion of tropane alkaloids into the medium. However, their addition led to lysis of transformed roots. (C) 1998 Elsevier Science Ltd. All rights reserved.