title: Transcriptome analysis of Thapsia laciniata Rouy provides insights into terpenoid biosynthesis and diversity in Apiaceae.
abstract: Thapsia laciniata Rouy (Apiaceae) produces irregular and regular sesquiterpenoids with thapsane and guaiene carbon skeletons, as found in other Apiaceae species. A transcriptomic analysis utilizing Illumina next-generation sequencing enabled the identification of novel genes involved in the biosynthesis of terpenoids in Thapsia. From 66.78 million HQ paired-end reads obtained from T. laciniata roots, 64.58 million were assembled into 76,565 contigs (N50: 1261 bp). Seventeen contigs were annotated as terpene synthases and five of these were predicted to be sesquiterpene synthases. Of the 67 contigs annotated as cytochromes P450, 18 of these are part of the CYP71 clade that primarily performs hydroxylations of specialized metabolites. Three contigs annotated as aldehyde dehydrogenases grouped phylogenetically with the characterized ALDH1 from Artemisia annua and three contigs annotated as alcohol dehydrogenases grouped with the recently described ADH1 from A. annua. ALDH1 and ADH1 were characterized as part of the artemisinin biosynthesis. We have produced a comprehensive EST dataset for T. laciniata roots, which contains a large sample of the T. laciniata transcriptome. These transcriptome data provide the foundation for future research into the molecular basis for terpenoid biosynthesis in Thapsia and on the evolution of terpenoids in Apiaceae.
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Sciences, University of Copenhagen, Frederiksberg DK-1871, Denmark. hts@life.ku.dk.
authors.forename: Damian Paul
authors.initials: DP
authors.lastname: Drew
authors.forename: Bjørn
authors.initials: B
authors.lastname: Dueholm
authors.forename: Corinna
authors.initials: C
authors.lastname: Weitzel
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.forename: Christoph W
authors.initials: CW
authors.lastname: Sensen
authors.forename: Henrik Toft
authors.initials: HT
authors.lastname: Simonsen
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism; D019883:Alkyl and Aryl Transferases; D000595:Amino Acid Sequence; D044822:Biodiversity; D002952:Citric Acid Cycle; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D004587:Electrophoresis, Agar Gel; D020869:Gene Expression Profiling / Q000379:methods*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D051228:Geranyltranstransferase / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA; D012717:Sesquiterpenes / Q000378:metabolism; D013729:Terpenes / Q000737:chemistry / Q000378:metabolism*; D053629:Thapsia / Q000201:enzymology / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D012717:Sesquiterpenes; D013729:Terpenes; D003577:Cytochrome P-450 Enzyme System; D000444:Aldehyde Dehydrogenase; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase; D051228:Geranyltranstransferase