The Eucalyptus terpene synthase gene family

Area of Science:

• Plant Genomics
• Biochemistry
• Evolutionary Biology

Background:

• Terpenoids are key compounds in Eucalyptus, contributing to scent, economic value, and ecological interactions.
• Significant quantitative and qualitative variation in terpenes exists within and between Eucalyptus species.

Purpose of the Study:

• To identify and compare terpene synthase (TPS) genes in Eucalyptus grandis and E. globulus.
• To investigate the expression patterns of TPS genes across various Eucalyptus tissues.
• To functionally characterize selected TPS genes from E. grandis.

Main Methods:

• Genome mining of TPS genes in E. grandis and E. globulus.
• Comparative analysis with TPS genes from other plant species.
• Quantitative real-time PCR for gene expression analysis in seven tissues.
• In vitro functional characterization of five E. grandis TPS genes.

Main Results:

• Eucalyptus grandis possesses the highest number of putative functional TPS genes among sequenced plants (113), with E. globulus having 106.
• Most TPS genes (all but one in E. grandis) are expressed in at least one of the seven examined tissues.
• Genomic clusters of up to 20 TPS genes were identified, indicating potential for gene duplication and evolution.
• Significant expression of TPS genes was observed in non-leaf tissues, challenging previous assumptions about terpene function.

Conclusions:

• Terpenes in Eucalyptus likely play a more extensive role in biotic and abiotic interactions than previously understood.
• Tissue-specific expression patterns suggest specialized functions and potential roles in stress responses.
• Phylogenetic analysis reveals insights into the recent evolution of the TPS gene family, including gene duplication and loss of function events.