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Article|01 Oct 2021|OPEN
Sclareol and linalyl acetate are produced by glandular trichomes through the MEP pathway
Camille Chalvin1, Stéphanie Drevensek1, Françoise Gilard1, Caroline Mauve1, Christel Chollet1, Halima Morin1, Edith Nicol2, Eva Héripré3, Lucie Kriegshauser1, Bertrand Gakière1, Michel Dron1, Abdelhafid Bendahmane1 & Adnane Boualem1,
1Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405 Orsay, France
2Molecular Chemistry Laboratory (LCM), UMR 9168, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91128 Palaiseau Cedex, France
3Laboratory of Mechanics of Soils, Structures and Materials (MSSMAT), UMR 8579, CNRS, Ecole CentraleSupélec, Université Paris-Saclay, Bâtiment Eiffel, 8-10 rue Joliot-Curie, 91190 Gif-Sur-Yvette, France

Horticulture Research 8,
Article number: 206 (2021)
doi: 10.1038/hortres.2021.206
Views: 91

Received: 10 Apr 2021
Revised: 09 Jul 2021
Accepted: 22 Jul 2021
Published online: 01 Oct 2021

Abstract

Sclareol, an antifungal specialized metabolite produced by clary sage, Salvia sclarea, is the starting plant natural molecule used for the hemisynthesis of the perfume ingredient ambroxide. Sclareol is mainly produced in clary sage flower calyces; however, the cellular localization of the sclareol biosynthesis remains unknown. To elucidate the site of sclareol biosynthesis, we analyzed its spatial distribution in the clary sage calyx epidermis using laser desorption/ionization mass spectrometry imaging (LDI–FTICR-MSI) and investigated the expression profile of sclareol biosynthesis genes in isolated glandular trichomes (GTs). We showed that sclareol specifically accumulates in GTs’ gland cells in which sclareol biosynthesis genes are strongly expressed. We next isolated a glabrous beardless mutant and demonstrate that more than 90% of the sclareol is produced by the large capitate GTs. Feeding experiments, using 1-13C-glucose, and specific enzyme inhibitors further revealed that the methylerythritol-phosphate (MEP) biosynthetic pathway is the main source of isopentenyl diphosphate (IPP) precursor used for the biosynthesis of sclareol. Our findings demonstrate that sclareol is an MEP-derived diterpene produced by large capitate GTs in clary sage emphasing the role of GTs as biofactories dedicated to the production of specialized metabolites.