Morpho-physiological reactions of mosses to the action of abiotic factors on post-technogenic areas of sulphur deposite

Abstract

The morphological structure of turfs and the activity of the main enzymes of antioxidant protection: peroxidase, superoxide dismutase (SOD) and catalase of the dominant species of mosses Barbula unguiculata Hedw,, Bryum caespiticium Hedw., Bryum argenteum Hedw. and Brachythecium salebrosum (Hoffm. eх F.Weber & D. Mohr) Schimp. from different transects of the northern exposure of sulfur mining dump No. 1 in the summer and autumn seasons were studied. It is shown that the morphological structure of the turfs of the mosses Bryum argenteum and Brachythecium salebrosum in the post-technological areas of sulfur mining is important for moisture conservation and depends on the microclimatic conditions of local growth and the life form of the species. It was found that the activity of enzymes depends on the species characteristics of mosses. The dependence of the activity of antioxidant enzymes in the investigated mosses on the intensity of light and temperature on the transects of dump No. 1 was defined. In the summer period, the highest indicators of the activity of antioxidant enzymes were noted in moss samples from the northern top of the dump, where the influence of high temperatures and light intensity, as well as lack of moisture, are particularly noticeable. Under the experimental conditions, in Barbula unguiculata and Bryum caespiticium from the northern top of the dump, under the influence of 24-hour exposure to a temperature of 42 °C, the most significant increase in peroxidase activity by 1.2–1.4 and SOD by 1.6–1.9 times was found. Increasing in peroxidase activity and SOD caused by hyperthermia were reversed by pretreatment with the protein biosynthesis inhibitor cyclohexamide, that may indicate about involvement of the protein synthesizing system in this process. It is likely that the increasing of the activity of antioxidant enzymes is caused primarily by the change in gene expression of stress proteins that control the synthesis of specific adaptogens and protectors, indicating that the extreme conditions of an anthropogenically transformed environment contribute to the development of forms of organisms with the highest potential opportunities.