Plants are master chemists and research in the Last group focuses on regulation and evolution of metabolic enzymes and biosynthetic networks that produce the dazzling array of compounds found in the Plantae. Central and specialized metabolism have a number of notable bridges between them. The building blocks of specialized metabolism generally derive from central metabolism (for instance, amino acid biosynthesis). Specialized metabolic enzymes frequently are ‘recruited’ from proteins that function in central metabolism. The talk will have two components. First I will describe our work on the allosteric regulatory network of Leu, Ile and Val in Arabidopsis. The second part of the talk will focus on the relationship between branched chain amino acid metabolism and Solanaceae trichome specialized metabolism. This will illustrate how ‘old’ enzymes that make the building blocks of all life are repurposed over evolutionary time to create the tremendous metabolic diversity we associate with plants.