Generation of novel medicinal plants by metabolic engineering

Plants produce a plethora of valuable natural products, many of which are used by humans as nutrients, colorants, flavors, fragrances, and pharmaceutics. For numerous natural products the dependency on natural occurring resources strongly limits their availability due to their occurance in eventually endangered species, due to the minute amounts of metabolites present in plant tissue, and due to the reluctance of many medicinal plants to propagation and cultivation in sufficient quantities. During the last decades an enormous amount of knowledge has been generated regarding the biochemistry and genetics of numerous complex natural product biosynthesis pathways in plants, like those leading to morphinans, terpenoid indole alkaloids, or lignans. This steadily increasing knowledge know opens up opportunities to engineer these pathways in heterologous hosts but also for metabolic engineering of those pathways to significantly enhance the yield of the desired products in planta. Additionally, novel catalysts like the human cytochrome P450 monooxygenases can be engineered into plants, presenting unique options to manipulate plant metabolism (1,2). Current achievements as well as future perspectives of metabolic engineering of medicinal plants will be evaluated in this presentation.