Involvement of compartmentalization in monoterpene and sesquiterpene biosynthesis in plants

Abstract

Terpenoids play numerous vital roles in basic plant processes with volatile monoterpenes and sesquiterpenes contributing to plant defense and reproduction. The biosynthesis of terpenoids in plants occurs in different subcellular compartments, which until recently were believed to include the cytosol, plastids, and mitochondria. The plastidic MEP pathway and the cytosolic MVA pathway give rise to IPP and DMAPP, which are subsequently utilized by prenyltransferases to produce prenyl diphosphates. It has been accepted that GPP and monoterpenes are synthesized in plastids, whereas FPP and sesquiterpenes are produced in the cytosol. Here we discuss how compartmentalization contributes to the formation of terpenoid diversity in plants in light of recent reports on new subcellular localizations for some enzymatic steps as well as on bifunctional terpene synthases capable of producing both mono- and sesquiterpenes.