INFLUENCE OF TEMPERATURE CONDITIONS ON THE ACCUMULATION OF PRIMARY AND SECONDARY METABOLITES BY LICHENS FLAVOCETRARIA CUCULLATA AND CETRARIA LAEVIGATA

Abstract

The study of the effect of temperature on the accumulation of primary and secondary metabolites by lichens Flavocetraria cucullata (Bellardi) Kärnefelt & Thell and Cetraria laevigata Rass was carried out. Lichen samples were taken out from under the snow (-20 °C) together with the soil substrate and transferred to the climatic chamber. Then the temperature in the climatic chamber was sequentially increased to +10 and +20 °C. The lichen exposure was carried out for 30 days for each temperature regime. The analysis of primary metabolites was performed by gas chromatography-mass spectrometry. It was shown that in lichens F. cucullata and C. laevigata at temperatures of +10 and +20 °C, an increase in the content of mannitol, ribitol, sucrose, and hydroxyproline was observed, as well as a decrease in the content of unsaturated fatty acids as compared to the initial samples. At the same time, the content of glycerol and arabitol in the thalli of the initial lichens (-20 °C) was higher than after exposure at +10 and +20 °C, which, apparently, is associated with the cryoprotective properties of these compounds. The content of secondary metabolites in lichens was determined by high performance liquid chromatography. It was shown that the content of usnic, allo-protolichesterinic, and protolichesterinic acids in F. cucullata increased after exposure in a climatic chamber, which may be associated with a general activation of metabolic processes with an increase in temperature. At the same time, the content of fumarprotocetraric acid in C. laevigata lichens decreased at temperatures of +10 and +20 °C compared to the initial samples, which may be associated with its protective properties under the action of low-temperature stress.