Catharanthus roseus produces two economically valuable anticancer drugs, vinblastineand vincristine. These drugs are members of the terpenoid indole alkaloids andaccumulate in small quantities within the plant; thus these two drugs are expensiveto produce. Metabolic engineering efforts have focused on increasing the alkaloids inthis pathway through various means such as elicitation, precursor
feeding, and geneoverexpression. Recently we successfully expressed
Arabidopsis genes encoding afeedback-insensitive anthranilate synthase
subunit under the control of theglucocorticoid-inducible promoter system and the anthranilate synthase
subunitunder the control of a constitutive promoter in
C. roseus hairy roots. In this work welook at the transient behaviors of terpenoid indole alkaloids over a 72 h inductionperiod in late
exponential growth phase cultures. Upon induction, the tryptophan,tryptamine, and ajmalicine pools accumulated over 72 h. In contrast, the lochnericine,hörhammericine, and tabersonine pools decreased and leveled out over the 72 hinduction period. Visible changes within the individual compounds usually took from4 to 12 h.