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Effects of terpenoid precursor feeding on Catharanthus roseus hairy roots over‐expressing the alpha or the alpha and beta subunits of anthranilate synthase
Author(s) -
Peebles Christie A.M.,
Hong SeungBeom,
Gibson Susan I.,
Shanks Jacqueline V.,
San KaYiu
Publication year - 2006
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20739
Subject(s) - loganin , catharanthus roseus , terpenoid , tryptamine , biochemistry , atp synthase , biology , harmine , tryptophan synthase , chemistry , enzyme , tryptophan , pharmacology , high performance liquid chromatography , amino acid , chromatography
Among the pharmacologically important terpenoid indole alkaloids produced by Catharanthus roseus are the anti‐cancer drugs vinblastine and vincristine. These two drugs are produced in small yields within the plant, which makes them expensive to produce commercially. Metabolic engineering has focused on increasing flux through this pathway by various means such as elicitation, precursor feeding, and introduction of genes encoding specific metabolic enzymes into the plant. Recently in our lab, a feedback‐resistant anthranilate synthase α subunit was over‐expressed in C. roseus hairy roots under the control of a glucocorticoid inducible promoter system. Upon induction we observed a large increase in the indole precursors, tryptophan, and tryptamine. The current work explores the effects of over‐expressing the anthranilate synthase α or α and β subunits in combination with feeding with the terpenoid precursors 1‐deoxy‐ D ‐xylulose, loganin, and secologanin. In feeding 1‐deoxy‐ D ‐xylulose to the hairy root line expressing the anthranilate synthase α subunit, we observed an increase of 125% in hörhammericine levels in the induced samples, while loganin feeding increased catharanthine by 45% in the induced samples. Loganin feeding to the hairy root line expressing anthranilate synthase α and β subunits increases catharanthine by 26%, ajmalicine by 84%, lochnericine by 119%, and tabersonine by 225% in the induced samples. These results suggest that the terpenoid precursors to the terpenoid indole alkaloids are important factors in terpenoid indole alkaloid production. © 2005 Wiley Periodicals, inc.