Regulation of metabolic networks as a conceptual frame to study plant signalling: a tribute to Pierre Gadal

Starting with the characterisation of metabolic pathways and kinetic properties of individual enzymes, it becomes obvious that considering only one aspect of plant metabolism is too restrictive to understand how a plant may function. From such an apparent, simple and quite trivial observation, we learn from Pierre Gadal that a plant physiologist has to bear in mind an integrative approach based on the concepts of “reversibility, modularity and compartmentation”. This leitmotiv influences some of us when studying “metabolic regulation” and/or “plant cell signalling”. The present paper aims at illustrating these seminal ideas.