Identification of BAHD acyltransferases associated with acylinositol biosynthesis inSolanum quitoense(naranjilla)

AbstractPlants make a variety of specialized metabolites that can mediate interactions with animals, microbes and competitor plants. Understanding how plants synthesize these compounds enables studies of their biological roles by manipulating their synthesisin vivoas well as producing themin vitro. Acylsugars are a group of protective metabolites that accumulate in the trichomes of many Solanaceae family plants. Acylinositol biosynthesis is of interest because it appears to be restricted to a subgroup of species within the Solanum genus. Previous work characterized a triacylinositol acetyltransferase involved in acylinositol biosynthesis in the Andean fruit plantSolanum quitoense(lulo or naranjillo). We characterized three additionalS. quitoensetrichome expressed enzymes, and found that virus induced gene silencing of each caused changes in acylinositol accumulation. Surprisingly, thein vitrotriacylinositol products of these enzymes are distinct from those that accumulatein planta. These enzymes, nonetheless, provide an opportunities to test the biological impact and properties of these triacylinositolsin vitro.