Geraniol-10-hydroxylase Activity and Its Relation to Monoterpene Indole Alkaloid Accumulation in Cell Suspension Cultures of Catharanthus roseus

Abstract

The activity of geraniol- 10-hydroxylase was greatly increased when Catharanthus roseus cells were transferred to a production medium for monoterpene indole alkaloids. Its activity pattern showed a closer relationship than tryptophan decarboxylase to the pattern of indole alkaloid accumulation. The intermediate accumulation of tryptamine and its later incorporation into ajmalicine indicated that the coordination of the two precursor pathways for the monoterpene indole alkaloid formation was not synchronized under the chosen culture conditions. A better tuning of these two pathways may shorten the time period for induction of indole alkaloid biosynthesis.