Extracellular Localization of the Diterpene Sclareol in Clary Sage (Salvia sclarea L., Lamiaceae)

Jean-Claude Caissard (1) , Thomas Olivier (2) , Claire Delbecque (3) , Sabine Palle (4) , Pierre-Philippe Garry (3) , Arthur Audran (3) , Nadine Valot (1) , Sandrine Moja (1) , Florence Nicolè (1) , Jean-Louis Magnard (1) , Sylvain Legrand (1, 5) , Sylvie Baudino (1) , Frédéric Jullien (1)

1 LBVPAM - Laboratoire de Biotechnologies Végétales appliquées aux Plantes Aromatiques et Médicinales
2 LHC - Laboratoire Hubert Curien
3 Bontoux SA
4 CMCM - Centre de Microscopie Confocale Multiphotonique
5 SADV - Stress Abiotiques et Différenciation des Végétaux Cultivés

Sclareol is a high-value natural product obtained by solid/liquid extraction of clary sage (Salvia sclarea L.) inflorescences. Because processes of excretion and accumulation of this labdane diterpene are unknown, the aim of this work was to gain knowledge on its sites of accumulation in planta. Samples were collected in natura or during different steps of the industrial process of extraction (steam distillation and solid/liquid extraction). Samples were then analysed with a combination of complementary analytical techniques (gas chromatography coupled to a mass spectrometer, polarized light microscopy, environmental scanning electron microscopy, two-photon fluorescence microscopy, second harmonic generation microscopy). According to the literature, it is hypothesized that sclareol is localized in oil pockets of secretory trichomes. This study demonstrates that this is not the case and that sclareol accumulates in a crystalline epicuticular form, mostly on calyces.

Domains: Life Sciences [q-bio]; Vegetal Biology

Jean-Claude Caissard, Thomas Olivier, Claire Delbecque, Sabine Palle, Pierre-Philippe Garry, et al.. Extracellular Localization of the Diterpene Sclareol in Clary Sage (Salvia sclarea L., Lamiaceae). PLoS Biology, 2012, 7 (10), pp.e48253. ⟨10.1371/journal.pone.0048253⟩. ⟨ujm-00749471⟩