Tropane Alkaloid Production in Root Cultures of Duboisia myoporoides Obtained by Repeated Selection

Abstract

Repeated selection of root lines that were highly productive for scopolamine was investigated for Agrobacterium rhizogenes-transformed and untransformed roots of Duboisia myoporoides. Lines highly productive for scopolamine could be selected by repeated selection of transformed roots, but not by repeated selection of untransformed ones. In transformed root cultures, the scopolamine content of the highest scopolamine-producing root line after 8 selections was 3. 2% dry weight (DW) as compared to 0. 15% DW for the parent line. The total alkaloid contents and scopolamine/hyoscyamine ratio also increased. Repeated selection decreased growth from 7. 0 to 2. 2g/liter, but there was no correlation between growth and scopolamine content in the selected transformed root cultures. This enhancement of scopolamine content and decrease of growth appears to be caused by the heterogeneous nature of the transformed roots.