Biosynthesis of linalyl acetate and other terpenes in lemon mint (Mentha aquatica var. citrata, Lamiaceae) glandular trichomes

The potential to produce and accumulate mono- and sesquiterpenes in lemon mint (Mentha aquatica var. citrata) glandular trichomes was evaluated. Volatiles were extracted using methyl-tert-butyl ether or solid phase micro extraction and determined by gas chromatography-mass spectrometry. The main components of the essential oil of lemon mint are the monoterpene alcohol linalool and its ester linalyl acetate. Sesquiterpenes, such as elemol, (E)-caryophyllene, and germacrene D, as well as the monoterpenes 1,8-cineole, β-myrcene, and β-(E)-ocimene, are also prominent. Most of the essential oil is localized in the glands, as leaves devoid of trichomes had very low essential oil levels. The quantities of all these components per leaf increased during leaf development until reaching the third whorl, and then the levels remained steady. Conversely, the essential oil content per gram fresh weight decreased with leaf development, but the decrease was not statistically significant at p = 0.05. Desalted cell-free ext...