|Garcia Rutledge, Elizabeth|
Submitted to: Plant Biology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/24/2009
Publication Date: 5/1/2009
Citation: Kirby, J., Nowroozi, F., Withers, S.T., Park, J.G., Nishimoto, M., Behrendt, D., Garcia Rutledge, E.J., Fortman, J.L., Johnson, H.E., Anderson, J.V., Keasling, J.D. 2009. An Exploration of Diterpene Biosynthesis in the Euphorbiaceae. Plant Biology Annual Meeting, July 18-22, 2009, Honolulu, HI. Secondary Metabolism and Natural Products, Abstract #P60047. Interpretive Summary:
Technical Abstract: Terpenes constitute one of the most structurally diverse groups of natural products found in nature. In plants they range from essential and relatively universal primary metabolites, such as sterols, carotenoids, and hormones, to more unique secondary metabolites that serve roles in plant defense and communication. A large number of terpenes have been isolated from plants of the Euphorbiaceae family and the most interesting of these from a therapeutic standpoint contain diterpene (C20) backbones. Specific Euphorbiaceae diterpenes of medical interest include the latent-HIV activator prostratin (and related phorbol esters), the analgesic resiniferatoxin, and a family of anticancer drugs related to ingenol. In spite of the large number of diterpenes isolated from these plants and the similarity of their core structures, there is little known about their biosynthetic pathways. Here, we have chosen four Euphorbiaceae species to investigate terpene biosynthesis and report on the distribution of diterpene synthases in these plants. Other than the universal kaurene synthase, the only diterpene synthase isolated to date from the Euphorbiaceae has been casbene synthase, responsible for biosynthesis of the macrocyclic diterpene casbene in the castor bean (Ricinus communis). We have since discovered genes encoding casbene synthases in our selected Euphorbiaceae species and have demonstrated casbene production in engineered microbial hosts. The prevalence of casbene synthase in the Euphorbiaceae and implications for diterpene biosynthesis in this plant family is discussed.