(746h) Examining the Transcriptional Response of Overexpressing Anthranilate Synthase in Catharanthus Roseus Hairy Roots

Catharanthus roseus produces a variety of terpenoid indole alkaloids (TIAs) including valuable anti-cancer drugs vinblastine and vincristine.  Previous study has shown over expression of a feedback insensitive anthranilate synthase αβ unit (ASαβ) behind an inducible promoter in C. roseus hairy roots increase the levels of some TIA metabolites, but decrease the levels of other TIA metabolites.

Although the genetic modification is targeted to ASαβ, we hypothesized that expression of other genes in the TIA pathway would be altered. In order to determine the transcriptional response caused by the overexpression of ASαβ, we utilized RT-qPCR to analyze the transcriptional response of all known TIA genes and regulators after 12, 24, and 48 hours of induction (i.e. increased expression of ASαβ).  The results indicate an increase in mRNA abundance for some TIA genes and regulators while the mRNA abundance decreases for others.  The results and their implications for engineering increased TIA production in C. roseus hairy roots will be discussed.