Abstract: Terpenoids are called“terpenome”for their structural diversities . Besides their important roles in plant growth, development and environmental responses, terpenoids have been widely used in medicine and organic chemicals . The biosynthesis of terpenoids in plants can be conceptually divided into three discrete processes: the formation of terpene precursors,
the construction of terpene skeletons, followed by the complex post-modifications . After the skeleton construction by terpene synthases (TPS) , diverse reactions catalyzed by the responsible post-modification enzymes result in tens of thousands of terpenoids . In this paper, with our preliminary studies on the biosynthesis of Isodon diterpenes, a number of representative
post-modification enzymes of plant terpenoids formation reported in recent years are reviewed , which include P450 monooxidases, double-bond reductases, acyltransferases and glycosyltransferases .

Key words: Terpene synthases