Ecological aspects of regulation of the plasticity of accumulation of terpene compounds in plants

Abstract

Field mint (Mentha arvensis L.) of the Mentha (Lamiaceae) is one of the most important species among medicinal and essential oil-bearing plant. The content of essential oils in the plants of field mint M. arvensis was studied depending on the growing conditions in three biocoenoses, taking into account the increase in soil moisture availability. The output of essential oil from the aboveground part of mint plants was maximum during the mass flowering phase and amounted to 2.7±0.08% in mesohydrophytic biocoenoses, 2.3±0.09% in mesophytic and 1.3±0.11% in xeromesophytic biocoenoses. Cyclic terpenes and terpenoids (65.2 and 59.8%, respectively) predominated in the composition of the field mint plants oil of mesohydrophytic and mesophytic biocoenoses, the soil moisture content of which is more consistent with the mesophilic ancestral ecology of the species, while acyclic compounds accounted for 31.2 and 34.6 %. Simpler acyclic terpenes and terpenoids dominated in the field mint oil profile of xeromesophytic biocoenoses (55.3%). The essential oil of mint plants of all three ecological biocoenoses contained terpenes with a pronounced protective function -α- terpinene, γ-terpinolen, trans and cis-ocimene, eucalyptol (1,8 cineol), which exhibit broad antimicrobial and insecticidal properties. The concentration of these compounds was maximal in plants of the xeromesophytic biocoenoses. While the maximum content of volatile terpenes (β-myrcene, cis-geraniol, nerol acetate), which perform an attractive function (ensures the relationship of plants with insects), is recorded in the mesohydrophytic biocoenoses. The adaptation of mint plants to different ecological conditions is ensured by the shift in the activity of secondary metabolism towards increasing the synthesis of simpler in structure and less energy-intensive components, which provides the population with a selective advantage as the species moves to new habitats that differ in ecological conditions from those specific to ancestral forms.