PRODUCTION OF TROPANE ALKALOIDS IN GENETICALLY-ENGINEERED ROOT CULTURES

Hyoscyamine 6beta-hydroxylase catalyses the oxidative reactions in the biosynthetic pathway leading from hyoscyamine to scopolamine. The hydroxylase gene of Hyoscyamus niger was placed under the control of the cauliflower mosaic virus 35S promoter and introduced to hyoscyamine-rich Atropa belladonna by a binary vector system using Agrobacterium rhizogenes. The presence of the transgene in kanamycin-resistant hairy roots was confirmed by the analysis using polymerase chain reaction. The engineered belladonna hairy roots showed increased amounts and enzyme activities of the hydroxylase, and contained up to five-fold higher concentrations of scopolamine than wild-type hairy roots. The contents of 6beta-hydroxyhyoscyamine also increased in the transformed roots. Such genetically engineered hairy roots should be useful for enhancing scopolamine productivity in in vitro root culture systems.