EFFECTS OF ABIOTIC FACTORS ON INTERNAL HOMEOSTASIS OF MENTHA SPICATA LEAVES

Mentha spicata plants were subjected to various abiotic stresses in order to evaluate the triggering of signals and the phenolic compound levels of leaves. Total phenolic compound levels exhibited specific responses to a particular abiotic stress factor that responded rapidly to drought exposure, light intensity, and with a slight change in response to salt stress and heat stress. A parallel change was found in an elevation in hydrogen peroxide (H2O2) contents. Change in anthocyanin and carotenoid contents in response to drought, different light intensities, salinity and temperature stress was encountered with a change in H2O2. A change in the malondialdehyde level was also exhibited, depending on the levels of oxidant and antioxidant availability during particular abiotic stress factors. This risk was accomplished by the regulation of phenylalanine ammonia lyase activity. Prolonged exposure showed a reduction in chlorophyll content. Higher anthocyanin, carotenoid, H2O2 and total phenolic compound levels were expressed in the plasticity of plant acclimation at different levels. The tolerance of abiotic stress factors is apparently closely associated with the non-enzymatic antioxidant system via metabolome readjustment. We suggest that biosynthesis of these compounds is tightly regulated, reflecting plant plasticity when acclimating to different types of abiotic stress.