Isolation and partial characterisation of a putative monoterpene synthase from Melaleuca alternifolia

Plant Physiol Biochem. 2004 Dec;42(11):875-82. doi: 10.1016/j.plaphy.2004.10.010. Epub 2004 Dec 15.


Melaleuca alternifolia (Cheel) is an Australia native tree harvested for its monoterpene-rich, essential oil. Monoterpene synthases (E.C. were partially purified from the flush growth of the commercially important, high terpinen-4-ol chemotype of M. alternifolia. The purified fractions produced an acyclic monoterpene, linalool that is not present in the essential oil. To further characterise the monoterpene synthase, a cDNA library was constructed and 500 expressed sequence tags (ESTs) were sequenced to isolate putative terpene synthases. A single clone with similarity to the TspB gene sub-family of angiosperm monoterpene and isoprene synthases was isolated but was truncated at the 5' end. This single clone was used to design a probe for a cDNA library and was applied to isolate a full-length clone. This gene encoded a polypeptide 583 amino acids in length (67 kDa) including a putative transit peptide. Heterologous expression of the gene in Escherichia coli and subsequent assay of the recombinant enzyme did not result in the production of terpinen-4-ol, the major constituent of tea tree oil, or of its precursor sabinene hydrate. Significant quantities of linalool were observed in these assays, and in the assays of monoterpene synthase activity of a native enzyme in vitro, but the racemic nature of the linalool means that it may have a non-enzymatic origin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cloning, Molecular
  • Escherichia coli / genetics
  • Expressed Sequence Tags*
  • Gene Library
  • Intramolecular Lyases / isolation & purification
  • Intramolecular Lyases / metabolism*
  • Melaleuca / enzymology*
  • Melaleuca / genetics
  • Molecular Sequence Data
  • Monoterpenes / chemistry*
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism*


  • Monoterpenes
  • Recombinant Proteins
  • Intramolecular Lyases
  • pinene cyclase I

Associated data

  • GENBANK/AY279379