Teucrium scordium L. and Mentha pulegium L. essential oil importance in adaptive response to salinity stress

Plant secondary metabolites, including essential oils, are very important in the adaptive responses to stress conditions. Salt stress is a major element in natural saline habitats. Plants adapted to variations in substrate salinity (such as facultative halophytes) are very suitable for comparative analysis of the adaptive response under saline conditions on natural habitats. Based on their distribution on both saline and non-saline habitats, Teucrium scordium L. and Mentha pulegium L. were selected to determine the potential importance of essential oil components in the adaptive response to salt-induced stress conditions as stress-related metabolites. Quantitativequalitative analysis of essential oils in plant material of the tested species sampled from two saline habitats was performed and compared with samples from non-saline habitat. The prepared plant material of T. scordium and M. pulegium was hydrodistilled using a Clevenger-type apparatus by standard procedure. Volatile compounds were analyzed by GC/MS. The qualitative composition of the T. scordium and M. pulegium essential oils are related to the substrate salinity. The results obtained for the composition of the essential oils indicate that the adaptive response is specific and can be taxonomically related. Both analyzed plants are characterized by the increased synthesis of individual components of essential oil that are potentially important in the adaptive response to saline stress conditions. The adaptive response to saline stress of the analyzed plants includes increased synthesis of individual components of essential oils. Essential oil components such as alpha-pinene, beta-pinene, beta-caryophyllene, limonene and caryophyllene oxide, as well as piperitenone, pulegone, isopulegone are important in the adaptive response on saline habitats for T. scordium and M. pulegium, respectively.