Alternative metabolic fates of hygrine in transformed root cultures of Nicandra physaloides.

Alkaloid production by several Agrobacterium rhizogenes-transformed root lines of Nicandra physaloides was studied. Early in the culture cycle all lines contained predominantly hygrine, which has previously been reported to be the major alkaloid in roots of this plant. A number of other hygrine-derived alkaloids were identified, and these generally increased in importance as the cultures matured. Some lines were found to differ quite markedly in the relative importance of the different hygrine-derived alkaloids. The possibility is raised that alkaloid biosynthesis in N. physaloides root cultures may be a good model system in which to study metabolite partitioning in branched metabolic pathways.