title: Genomic characterization, molecular cloning and expression analysis of two terpene synthases from Thymus caespititius (Lamiaceae).
abstract: The identification, isolation and functional characterization of two genes encoding two monoterpene synthases-γ-terpinene synthase (Tctps2) and α-terpineol synthase (Tctps5)-from three chemically distinct Thymus caespititius (Lamiaceae) genotypes were performed. Genomic exon-intron structure was also determined for both terpene synthase genes, revealing an organization with seven exons and six introns. The cDNA of Tctps2 was 2,308 bp long and had an open reading frame of 1,794 bp encoding for a protein with 598 amino acids. Tctps5 was longer, mainly due to intron sequences, and presented high intraspecific variability on the plants analyzed. It encoded for a protein of 602 amino acids from an open reading frame of 1,806 bp comprising a total of 2,507 bp genomic sequence. The amino acid sequence of these two active Tctps genes shared 74 % pairwise identity, ranging between 42 and 94 % similarity with about 50 known terpene synthases of other Lamiaceae species. Gene expression revealed a multi-product Tctps2 and Tctps5 enzymes, producing γ-terpinene and α-terpineol as major components, respectively. These enzymatic results were consistent with the monoterpene profile present in T. caespititius field plants, suggesting a transcriptional regulation in leaves. Herewith reported for the first time for this species, these two newly characterized Tctps genes improve the understanding of the molecular mechanisms of reaction responsible for terpene biosynthesis and chemical diversity found in T. caespititius.
authors.affiliation: Departmento de Biologia Vegetal, Faculdade de Ciências, Centro de Biotecnologia Vegetal, Instituto de Biotecnologia e Bioengenharia, Universidade de Lisboa, C2, Campo Grande, 1749-016 Lisbon, Portugal.
authors.forename: A Sofia
authors.initials: AS
authors.lastname: Lima
authors.forename: Jette
authors.initials: J
authors.lastname: Schimmel
authors.forename: Brigitte
authors.initials: B
authors.lastname: Lukas
authors.forename: Johannes
authors.initials: J
authors.lastname: Novak
authors.forename: José G
authors.initials: JG
authors.lastname: Barroso
authors.forename: A Cristina
authors.initials: AC
authors.lastname: Figueiredo
authors.forename: Luis G
authors.initials: LG
authors.lastname: Pedro
authors.forename: Jörg
authors.initials: J
authors.lastname: Degenhardt
authors.forename: Helena
authors.initials: H
authors.lastname: Trindade
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D007438:Introns; D019686:Lamiaceae / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D010940:Plant Proteins; D019883:Alkyl and Aryl Transferases; C022723:gamma-terpinene synthetase; C108877:terpene synthase