Ethephon Induced Alkaloid Production in Two Varieties of the Medicinal Plant Catharanthus Roseus

Many plant-derived secondary metabolites have chemical properties that give them therapeutic value for the treatment of cancers, hypertension, and other common illnesses. In the medicinal plant Catharanthus roseus, the secondary metabolites of interest are the monoterpene idole alkaloids (MIAs) vinblastine and vincristine, which are naturally produced at relatively low levels in the most commonly used varieties. As a result, pharmaceutical scientists instead extract intermediate compounds from the MIA biosynthetic pathway and chemically synthesize the final products in vitro—a difficult and costly process. Medicinal chemists have historically used methyl jasmonate, a plant signaling hormone, to induce higher levels of vinblastine and vincristine in planta for their research, but this particular treatment is too expensive for practical use in a large-scale agricultural or biopharmaceutical production setting. In the course of our research, we examined alternatives to chemical synthesis and methyl jasmonate induction by assaying alkaloid concentrations in two of the most commonly used varieties of C. roseus. We present our findings here, as well as the effect of an ethylene derivative as an induction agent. The ultimate goal of this research is to understand how to upregulate biosynthesis of medically-relevant indole alkaloids in the native host plant.