Bornyl-diphosphate synthase from Lavandula angustifolia: A major monoterpene synthase involved in essential oil quality. (May 2017)

• Record Type: Journal Article
• Authors: Despinasse, Yolande; Fiorucci, Sébastien; Antonczak, Serge; Moja, Sandrine; Bony, Aurélie; Nicolè, Florence; Baudino, Sylvie; Magnard, Jean-Louis; Jullien, Frédéric
• Is Part Of: Phytochemistry. Volume 137(2017)
• Page Start: 24
• Page End: 33
• Publication Date: 2017-05
• Subjects: Lavandula angustifolia (Lamiaceae) -- Terpene synthase -- Transcript regulation -- Camphor; Botanical chemistry -- Periodicals; Biochemistry -- Periodicals; Botany -- Periodicals; Chimie végétale -- Périodiques; 572.2
• DOI: 10.1016/j.phytochem.2017.01.015
• Languages: English
• ISSNs: 0031-9422

Abstract

Abstract: Lavender essential oils (EOs) of higher quality are produced by a few Lavandula angustifolia cultivars and mainly used in the perfume industry. Undesirable compounds such as camphor and borneol are also synthesized by lavender leading to a depreciated EO. Here, we report the cloning of bornyl diphosphate synthase of lavender ( LaBPPS ), an enzyme that catalyzes the production of bornyl diphosphate (BPP) and then by-products such as borneol or camphor, from an EST library. Compared to the BPPS of Salvia officinalis, the functional characterization of LaBPPS showed several differences in amino acid sequence, and the distribution of catalyzed products. Molecular modeling of the enzyme's active site suggests that the carbocation intermediates are more stable in LaBPPS than in SoBPPS leading probably to a lower efficiency of LaBPPS to convert GPP into BPP. Quantitative RT-PCR performed from leaves and flowers at different development stages of L. angustifolia samples show a clear correlation between transcript level of LaBPPS and accumulation of borneol/camphor, suggesting that LaBPPS is mainly responsible of in vivo biosynthesis of borneol/camphor in fine lavender. A phylogenetic analysis of terpene synthases (TPS) pointed out the basal position of LaBPPS in the TPSb clade, suggesting that LaBPPS could be an ancestor of others lavender TPSb. Finally, borneol could be one of the first monoterpenes to be synthesized in the Lavandula subgenus. Knowledge gained from these experiments will facilitate future studies to improve the lavender oils through metabolic engineering or plant breeding. Accession numbers: LaBPPS: KM015221. Graphical abstract: Characterization of a new bornyl-diphosphate synthase. In vitro product distribution from BPPS of lavender and sage is linked to active site shape. Highlights: A bornyl-diphosphate synthase of fine lavender (LaBPPS) is characterized. Enzymatic activity of LaBPPS and its ortholog from sage (SoBPPS) are compared. Modeling BPPS is performed to explain product distribution. qRT-PCR during flower blooming shows correlation between transcript level and borneol/camphor accumulation.