title: The terpene synthase gene family in Tripterygium wilfordii harbors a labdane-type diterpene synthase among the monoterpene synthase TPS-b subfamily.
abstract: Tripterygium wilfordii (Celastraceae) is a medicinal plant with anti-inflammatory and immunosuppressive properties. Identification of a vast array of unusual sesquiterpenoids, diterpenoids and triterpenoids in T. wilfordii has spurred investigations of their pharmacological properties. The tri-epoxide lactone triptolide was the first of many diterpenoids identified, attracting interest due to the spectrum of bioactivities. To probe the genetic underpinning of diterpenoid diversity, an expansion of the class II diterpene synthase (diTPS) family was recently identified in a leaf transcriptome. Following detection of triptolide and simple diterpene scaffolds in the root, we sequenced and mined the root transcriptome. This allowed identification of the root-specific complement of TPSs and an expansion in the class I diTPS family. Functional characterization of the class II diTPSs established their activities in the formation of four C-20 diphosphate intermediates, precursors of both generalized and specialized metabolism and a novel scaffold for Celastraceae. Functional pairs of the class I and II enzymes resulted in formation of three scaffolds, accounting for some of the terpenoid diversity found in T. wilfordii. The absence of activity-forming abietane-type diterpenes encouraged further testing of TPSs outside the canonical class I diTPS family. TwTPS27, close relative of mono-TPSs, was found to couple with TwTPS9, converting normal-copalyl diphosphate to miltiradiene. The phylogenetic distance to established diTPSs indicates neo-functionalization of TwTPS27 into a diTPS, a function not previously observed in the TPS-b subfamily. This example of evolutionary convergence expands the functionality of TPSs in the TPS-b family and may contribute miltiradiene to the diterpenoids of T. wilfordii.
authors: Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Copenhagen, DK-1871, Denmark.|Center for Synthetic Biology 'bioSYNergy' and Copenhagen Plant Sciences Centre, Copenhagen, Denmark.
authors: Nikolaj L
authors: NL
authors: Hansen
authors: Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Copenhagen, DK-1871, Denmark.|Center for Synthetic Biology 'bioSYNergy' and Copenhagen Plant Sciences Centre, Copenhagen, Denmark.
authors: Allison M
authors: AM
authors: Heskes
authors: Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Copenhagen, DK-1871, Denmark.|Center for Synthetic Biology 'bioSYNergy' and Copenhagen Plant Sciences Centre, Copenhagen, Denmark.
authors: Britta
authors: B
authors: Hamberger
authors: Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Copenhagen, DK-1871, Denmark.
authors: Carl E
authors: CE
authors: Olsen
authors: Science for Life Laboratory, Kungliga Tekniska Högskolan, Royal Institute of Technology, Stockholm, SE-171 21, Sweden.
authors: Björn M
authors: BM
authors: Hallström
authors: Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Copenhagen, DK-1871, Denmark.|Center for Synthetic Biology 'bioSYNergy' and Copenhagen Plant Sciences Centre, Copenhagen, Denmark.
authors: Johan
authors: J
authors: Andersen-Ranberg
authors: Plant Biochemistry Laboratory, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Copenhagen, DK-1871, Denmark.|Center for Synthetic Biology 'bioSYNergy' and Copenhagen Plant Sciences Centre, Copenhagen, Denmark.
authors: Björn
authors: 0000-0003-1249-1807
authors: B
authors: Hamberger
mesh_terms: D045784:Abietanes / Q000737:chemistry / Q000378:metabolism; D019883:Alkyl and Aryl Transferases / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D004224:Diterpenes / Q000737:chemistry / Q000378:metabolism; D004852:Epoxy Compounds / Q000737:chemistry / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D019753:Intramolecular Lyases / Q000235:genetics* / Q000378:metabolism; D015394:Molecular Structure; D039821:Monoterpenes / Q000737:chemistry / Q000378:metabolism; D005810:Multigene Family; D010616:Phenanthrenes / Q000737:chemistry / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D029757:Tripterygium / Q000201:enzymology / Q000235:genetics*
chemical_list: D045784:Abietanes; D004224:Diterpenes; D004852:Epoxy Compounds; D039821:Monoterpenes; D010616:Phenanthrenes; D010940:Plant Proteins; C001899:triptolide; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase; D019753:Intramolecular Lyases; C040265:pinene cyclase I
keywords: 
  Tripterygium wilfordii
  ; bioactive diterpenoids; convergent evolution; specialized metabolism; terpene synthase