ACTIVITY AND ISOZYME COMPOSITION OF PEROXIDASE IN SCOTS PINE (PINUS SYLVESTRIS L.) NEEDLES EFFECTED BY TECHNOGENIC EMISSIONS FROM VARIOUS ENTERPRISES AND VEHICLES

Background. The technogenic pollution leads to excessive production of reactive oxygen species (ROS) in plants which are highly reactive and toxic and cause damage to biomolecules. Plants have a complex antioxidant defense system that protects cells from the ROS and maintain homeostasis. The most important link this system is enzymes, in particular, peroxidase. It was of interest to determine the expression of the protective properties of one of the sensitive species of coniferous plants under the influence of technogenic emissions from various enterprises and vehicles. Purpose. Investigation the activity and isoenzyme composition of peroxidase in the needles of Pinus sylvestris L. under the influence of technogenic emissions of different compositions in the Baikal region. Materials and methods. The pine needles were collected on sample plots located near an aluminum plant, thermal power plant, chemical plant, coal mining enterprise, and the highway. The activity of soluble guaiacol-dependent peroxidases was defined by spectrophotometry in a reaction mixture with citrate-phosphate buffer, hydrogen peroxide, and guaiacol. Native polyacrylamide gel electrophoresis was used for determination of peroxidase isoforms. Results. It was shown that an increase in the total guaiacol-dependent peroxidase activity ranged from 6 to 22 times in the pine needles in polluted areas. Maximum enzyme activity was found in needle samples collected near the aluminum smelter, whose emissions are characterized by large amounts of fluorides and polycyclic aromatic hydrocarbons. The high variability of peroxidase isoform composition in Scots pine needles under industrial pollution was revealed. It was expressed in the emergence of new isoforms in the zone of fast-moving (Rf from 61 to 100) and medium-moving (Rf from 31 to 60) items. The maximum number of isoforms (nine) was found in pine needles near the aluminum smelter with only two ones detected in the background area. Conclusion. Peroxidase activity and the number of its newly formed isoforms can adequately reflect the degree of technogenic pollution and trees decline. The indicators can also be used in monitoring of coniferous forests condition.