NMR adventures in the metabolic labyrinth within plants

The era of metabolic engineering has begun, but them is only limited knowle dge about metabolic fluxes and how they are regulated in plants. Particular challenges am the non-linearities between enzyme abundances, metabolite co ncentrations and metabolic fluxes, and the existence of metabolic networks that provide multiple routes between many important metabolites, NMR offers the means to distinguish and quantitate the fluxes along different routes to key metabolites. NUR can therefore help us understand and resolve the ap parent paradox of, on the one hand, great metabolic flexibility evident in the natural responses of plants and, on the other hand, the unpredictable c hanges in metabolism reported in genetically engineered plants.