Robert Last - Metabolism at the tip of the trichome: the Solanaceae as a model system

Research in the Last group focuses on specialized metabolism in glandular trichomes of tomato and other plants in the Solanaceae. Acylsugars – relatively simple metabolites typically composed of sucrose or glucose and C2 to C12 acylesters – are produced in the tip cell of the long hairs of domesticated and wild tomato. Despite being derived from simple chemical building blocks, tremendous variation in acylsugar structures is observed within and across species. Some of the changes in products and enzymatic activities have occurred over remarkably short evolutionary timeframes. The talk will describe our results documenting ‘recruitment’ of enzymes of central metabolism to acylsugar biosynthesis, as well as studies of BAHD acyltransferase evolution. I will emphasize how comparative biochemistry led to insights into how gene duplication, neofunctionalization and gene loss contributed to the impressive acylsugar diversity observed in domesticated and wild tomato species. Work towards understanding the evolutionary history of this metabolic network over tens of millions of years of evolution of the Solanaceae will be described.