Regulation of plant phenolic synthesis: From biochemistry to ecology and evolution

The molecular and biochemical regulation of phenolic synthesis can be summarised as: (1) carbohydrates are partitioned in a manner ensuring growth; (2) carbohydrates are available for phenolic synthesis mainly during cell differentiation and after leaf maturation as the 'overflow'; (3) synthesis of a particular phenolic compound is specific to cell type and developmental stage; and (4) synthesis of certain phenolic compounds can be induced, independently of cell type, by factors such as wounding, microbial infection, and UV light. Recent advances in the understanding of the regulation of phenolic synthesis raises the question as to whether between-site and temporal variation in the amount and type of plants phenolics is due mostly to selection pressure by herbivores. Interdisciplinary studies by biochemists and ecologists are needed for a better understanding of the regulation of phenolic synthesis and plant-herbivore interactions mediated by secondary metabolites.