Identification, Functional Characterization, and Evolution of Terpene Synthases from a Basal Dicot

Area of Science:

• Plant biochemistry and molecular biology
• Evolutionary genomics of plant secondary metabolites

Background:

• Bay laurel (Laurus nobilis) is economically significant, with leaves rich in terpenes used in food, drugs, and cosmetics.
• Terpenes in Bay laurel contribute to its aroma and flavor, and possess potential pharmaceutical applications.
• Understanding terpene biosynthesis pathways is crucial for agricultural and medicinal advancements.

Purpose of the Study:

• To identify terpene synthases (TPS) responsible for volatile terpene production in L. nobilis leaves.
• To characterize the enzymatic activities of identified TPS genes.
• To investigate the evolutionary history of TPS gene clades within angiosperms.

Main Methods:

• RNA sequencing was employed to profile the transcriptome of L. nobilis leaves.
• Bioinformatic analyses were used to identify and isolate complementary DNAs (cDNAs) encoding TPS.
• Enzymatic characterization of selected TPS was performed to determine their catalytic products.

Main Results:

• Eight TPS complementary DNAs (cDNAs) were identified in L. nobilis.
• Characterized enzymes include a monoterpene synthase producing 1,8-cineole, a sesquiterpene synthase producing cadinenes, and a diterpene synthase producing geranyllinalool.
• Sequence comparisons suggest early evolution of TPS-a and TPS-b clades and ancestral geranyllinalool synthase activity in angiosperms.

Conclusions:

• The study successfully identified and characterized key TPS enzymes involved in Bay laurel terpene biosynthesis.
• The findings provide insights into the evolutionary origins of TPS gene families in angiosperms.
• This research lays the foundation for understanding and potentially manipulating terpene production in L. nobilis.