(681d) Overexpression of Multiple Terpenoid Indole Alkaloid Pathway Genes Increases Alkaloid Accumulation in Catharanthus Roseus Hairy Roots

Catharanthus roseus produces a wide variety of terpenoid indole alkaloids (TIAs) including the anti-hypertension drugs ajmalicine and serpentine and the anticancer drugs vinblastine and vincristine. The clinical importance of vinblastine and vincristine along with the very low yields in the plant has led researchers to investigate ways to increase the yield of these drugs within C. roseus . Our lab has chosen to study this system with C. roseus hairy roots because hairy root cultures offer a number of advantages over cell suspension culture including increased genetic stability and substantially higher alkaloid content. Transgenic hairy root lines were created that individually overexpressed 1-deoxy-D-xylulose synthase (DXS), geraniol 10-hydroxylase (G10H), and anthranilate synthase subunit α (ASA) under the control of a glucocorticoid-inducible promoter. We also created double overexpression lines that overexpressed DXS and ASA or DXS and G10H with both genes under control of a glucocorticoid-inducible promoter. We will present the results from these hairy root lines and discuss the importance of expressing multiple genes within the terpenoid indole alkaloid pathway.