PHYTOCHROME IS INVOLVED IN THE LIGHT-REGULATION OF VINDOLINE BIOSYNTHESIS IN CATHARANTHUS

The enzyme acetylcoenzyme A:deacetylvindoline 4-O-acetyl transferase (DAT) catalyzes the final step in the biosynthesis of the monoterpenoid indole alkaloid, vindoline. Previous studies have shown that the appearance of DAT activity in etiolated seedlings of Catharanthus roseus is induced by exposure of seedlings to light and that enzyme activity is restricted principally to the cotyledons. Evidence is now presented that phytochrome is involved in the light-mediated induction of DAT activity in Catharanthus cotyledons.