Synthesis and/or accumulation of bioactive molecules in the in vivo and in vitro root

Roots of many species are studied because of the presence of high-value biclactive molecules, yet few studies have attempted to determine the biosynthetic pathways of these compounds or the way in which synthesis is regulated. The presence of secondary metabolites in the root does not necessarily mean that this organ is also the site of synthesis. Thus the identification of organ-specific intermediate precursors and key enzymes is important for understanding the biosynthetic pathway and the regulation of biclactive molecules. This knowledge could allow researchers to predict the suitability of in vitro systems, such as regenerated roots and hairy roots, for producing the molecules of interest. In the present review, the production of biclactive molecules in in vivo roots is compared to that in in vitro untransformed and transformed roots, concentrating on recent developments in the study of the biosynthesis of the anti-cancer alkaloid camptothecin in Camptotheca acuminata Decne. The results of a recent study performed in our laboratory on the production of camptothecin and other secondary metabolites in in vivo and in vitro C. acuminata roots are also presented.