Implementation of functional genomics for gene discovery in alkaloid producing plants

Two centuries after the discovery of the first alkaloids, many enzymes involved in plant alkaloid biosynthesis have been identified. Nevertheless, the biosynthetic pathways for most of the plant alkaloids still remain incompletely characterised and understanding the regulatory mechanisms controlling the onset and flux of alkaloid biosynthesis is virtually inexistent. This information is however crucial to allow modelling of metabolic networks and predictive metabolic engineering. In the postgenomics era, new functional genomics tools, enabling comprehensive investigations of biological systems, are continuously emerging and are now gradually being implemented in the field of plant secondary metabolism as well. Here we discuss the advances these promising new technologies have already brought and may still bring with regard to the dissection of plant alkaloid biosynthesis. Encouraging results were obtained in alkaloid producing species such as Papaver somniferum, Catharanthus roseus and Nicotiana tabacum. Therefore we anticipate that functional genomics and the knowledge it brings along, will eventually allow a better exploitation of the plant biosynthetic machinery.