BACKGROUND : Terpenoids are abundant in the foliage of Eucalyptus, providing the characteristic smell as well
as being valuable economically and influencing ecological interactions. Quantitative and qualitative inter- and
intra- specific variation of terpenes is common in eucalypts.
RESULTS : The genome sequences of Eucalyptus grandis and E. globulus were mined for terpene synthase genes (TPS)
and compared to other plant species. We investigated the relative expression of TPS in seven plant tissues and
functionally characterized five TPS genes from E. grandis. Compared to other sequenced plant genomes, Eucalyptus
grandis has the largest number of putative functional TPS genes of any sequenced plant. We discovered 113 and
106 putative functional TPS genes in E. grandis and E. globulus, respectively. All but one TPS from E. grandis were
expressed in at least one of seven plant tissues examined. Genomic clusters of up to 20 genes were identified.
Many TPS are expressed in tissues other than leaves which invites a re-evaluation of the function of terpenes in
CONCLUSIONS : Our data indicate that terpenes in Eucalyptus may play a wider role in biotic and abiotic interactions
than previously thought. Tissue specific expression is common and the possibility of stress induction needs further
investigation. Phylogenetic comparison of the two investigated Eucalyptus species gives insight about recent
evolution of different clades within the TPS gene family. While the majority of TPS genes occur in orthologous
pairs some clades show evidence of recent gene duplication, as well as loss of function.
Additional file 1: This file contains 6 supplemental tables.
Additional file 2: This file contains 3 supplemental figures.
Additional file 3: This file contains 2 supplemental text documents.