Damage-Induced Variations in Essential Oil Composition and Volatile Emission in Aromatic Plants

BANCHIO, E.; VALLADARES, G.; GIORDANO, W.; ZYGADLO J.

Biomass Crops: Production, Energy and the Environment

Nova Science Publishers

Año: 2011; p. 139 - 152

Phytochemical induction of monoterpenes following herbivory by insects and mechanical damage, was studied in Minthostachys mollis (Lamiaceae), a plant native to Central Argentina with medicinal and aromatic uses in the region. The monoterpenes pulegone and menthone were analyzed in M. mollis 24 and 48 h after leaves were mechanically damaged or exposed to insects with different feeding habits (chewing, scraping, sap-sucking, and puncturing). Essential oil composition and emission of volatiles were assessed. Mechanical damage resulted in an increase of pulegone and menthone concentration in M. mollis essential oil during the first 24 h. Menthone content generally decreased whereas pulegone concentration increased in all treatments where insects were involved. The changes observed after insect feeding occurred also in the adjacent undamaged leaves, but induced changes after mechanical wounding were restricted to the damaged site, suggesting that an elicitor related to the insects may be required for a systemic response to be induced.             Changes in the volatiles released from M. mollis damaged leaves were also detected, most noticeably showing an increase in the emission of pulegone. Inducible chemical changes in aromatic plants might be common and widespread, affecting the specific compounds on which commercial exploitation is based.