Planta Med 2011; 77 - PI9
DOI: 10.1055/s-0031-1282602

Genomic characterization of γ-terpinene synthase from Thymus caespititius

AS Lima 1, B Lukas 2, J Novak 2, AC Figueiredo 1, LG Pedro 1, JG Barroso 1, H Trindade 1
  • 1Universidade de Lisboa, Faculdade de Ciências de Lisboa, Departamento de Biologia Vegetal, Instituto de Biotecnologia e Bioengenharia, Centro Biotecnologia Vegetal, C2, Campo Grande, 1749–016 Lisboa, Portugal
  • 2Institute for Applied Botany and Pharmacognosy, University of Veterinary Medicine, Veterinärplatz 1, 1210 Wien, Austria

Thymus caespititius Brot., commonly known as 'tormentelo' or 'erva-úrsula', is a Lamiaceae aromatic species endemic of the NW Iberian Peninsula, and of the Azores and Madeira archipelagos characterized for showing high essential oil chemical variability [1, 2].

Using eight chemically distinct Thymus caespititius accessions, collected at Pico and São Jorge islands (Azores) and in the Mainland Portugal, the genomic characterization of exon and intron numbers, sizes and placement, of a putative gene encoding a monoterpene synthase, γ-terpinene synthase (TcTPS2), was performed.

TcTPS2 is responsible for the first step of the 'cymyl'-pathway, giving rise to phenolic terpene isomers thymol and carvacrol and related compounds, main components in two of the chemotypes from T. caespititius essential oils.

The putative gene was organized in seven exons and six introns. With almost no variability on the plants analysed, TcTPS2 putatively encoded for a protein sequence of 598 amino acids from an open reading frame of 1794 bp, comprising a total of 2291 bp nucleotide sequence content. The deduced amino acid sequence of the putative gene showed a 98% pairwise identity, sharing 93% similarity with closely related Origanum species. A BLASTP search on GenBank revealed a high identity (65–58%) with other known terpene synthases from different members of other Lamiaceae species.

Herewith reported for the first time for the genus Thymus, this nucleotide identification approach improved the understanding of the genome organization of these genes.

Acknowledgement: This study was partially funded by the Fundação para a Ciência e Tecnologia (FCT) under research contracts PTDC/AGR-AAM/70136/2006 and PTDC/AGR-GPL/101334/2008.

References: 1. Figueiredo AC. et al. (2010) Natural Product Communications 5: 1465–1476.

2. Figueiredo AC et al. (2008) Cur Pharm Design 14: 3120–3140