Thursday, October 22, 2015
Small genetic changes, big phenotypic effects: the evolution of trichome specialized metabolism in Solanum and beyond
Department of Biochemistry and Molecular Biology, Department of Plant Biology, Michigan State University
Throughout human history plant-derived natural products were used in medicines, in cooking, as pest control agents, and in culturally important rituals. Plants produce these rapidly diversifying specialized metabolites as protective agents and to mediate interactions with beneficial organisms. Plant glandular secreting trichomes are epidermal protuberances that produce structurally diverse specialized metabolites, including acylated sugars. In vitro reconstruction of the cultivated tomato insect protective acylsucrose biosynthetic network showed that four BAHD acylsucrose acyltransferase enzymes are sufficient to produce the full set of naturally occurring compounds. Comparative biochemistry with the in vitro reconstitution system identified simple changes in enzyme structure leading to the acylsucrose diversity in trichomes of wild tomato. Ongoing work on trichome metabolites across the Solanaceae led to the identification of diverse acylated compounds and BAHD acyltransferases involved in the synthesis of novel compounds in S. quitoense (Naranjilla) and the basal species Salpiglossis sinuata. The talk will emphasize the power of analyzing biochemical processes through integration of comparative genomics with metabolite profiling, homology modeling, in vitro biochemistry and reverse genetics.
Contact : Simon Michaeli