Functional Characterization of a New Bifunctional Terpene Synthase LpNES1 from a Medicinal Plant Laggera pterodonta

Laggera pterodonta, known in China as 'Choulingdan' for its stimulous odor, has long been used as traditional herbal medicine. The essential oil of L. pterodonta, which exhibits various pharmacological activities, is a rich resource of monoterpenes and sesquiterpenes. To date, however, the terpene synthases responsible for their production remain unknown. In present study, a new terpene synthase gene (LpNES1) was identified from L. pterodonta, transcript level of which was significantly upregulated in response to methyl jasmonate treatment. Recombinant LpNES1 could synthesize (E)-nerolidol and minor beta-farnesene from farnesyl diphosphate and linalool from geranyl diphosphate in vitro. Whereas, only sesquiterpenes including (E)-nerolidol and minor beta-farnesene were released when LpNES1 was reconstituted in yeast, even coexpressed with a geranyl diphosphate synthase (ERG20(WW)). Combined with subcellular localization experiment, the result indicated that the cytosol-targeted LpNES1 was responsible for (E)-nerolidol biosynthesis exclusively in L. pterodonta. Additionally, the expression level of LpNES1 gene was more prominent in floral buds than that in other tissues. LpNES1 characterized in present study not only lays the molecular foundation for sesquiterpene biosynthesis of L. pterodonta, but provides a key element for further biosynthesis of bioactive compound in microbes.

Automated summary

In this study, a new terpene synthase gene LpNES1 was identified in Laggera pterodonta, responsible for the biosynthesis of (E)-nerolidol in the cytosol. The gene showed higher expression levels in floral buds. This discovery lays the foundation for sesquiterpene biosynthesis in L. pterodonta and provides a key element for further biosynthesis of bioactive compounds in microbes.