Plant cell cultures: Chemical factories of secondary metabolites.

This review deals with the production of high-value secondary metabolites including
pharmaceuticals and food additives through plant cell cultures, shoot cultures, root cultures and
transgenic roots obtained through biotechnological means. Plant cell and transgenic hairy root cultures
are promising potential alternative sources for the production of high-value secondary metabolites of
industrial importance. Recent developments in transgenic research have opened up the possibility of
the metabolic engineering of biosynthetic pathways to produce high-value secondary metabolites. The
production of the pungent food additive capsaicin, the natural colour anthocyanin and the natural
flavour vanillin is described in detail.