Plant cell and tissue culture: alternatives for metabolite production.

Plant cell culture systems represent a potential renewable source of valuable medicinals, flavours, essences and colourants that cannot be produced by microbial cells or chemical syntheses. However, only a few cultures produce these compounds in commercially useful amounts. The low productivities are associated with our poor understanding of the biochemistry of these systems. Recent advances in molecular biology, enzymology, physiology and fermentation technology of plant cell cultures suggest that these systems will become a viable source of important natural products. This review examines the sate of the art of production of medicinal plant secondary metabolites by plant cell cultures.