Prospects for the Metabolic Engineering of Bioactive Flavonoids and Related Phenylpropanoid Compounds

The successful engineering of complex metabolic pathways will require, in addition to availability of cloned genes and promoters, knowledge of the regulatory mechanisms that control metabolic flux into the pathway including post-translational phenomena such as metabolite channeling. We are interested in modifying pathways for the synthesis of isoflavonoids and other bioactive phenylpropanoid compounds in transgenic plants. We describe studies on flux control utilizing transgenic tobacco plants that under- and overexpress key biosynthetic enzymes, and outline experimental approaches for the molecular dissection of potential metabolic channels in the synthesis of antimicrobial flavonoid derivatives in alfalfa and other species.