ANALYSIS OF THE DYNAMICS OF THE COULTER GROUP OF THE SOD SEEDER FOR STRIP SOWING
One of the common soybean diseases is a necrotrophic pathogen - Septoria glycines Hemmi fungus. Fungal infection causes oxidative stress in plants and is accompanied by increased formation of reactive oxygen species and peroxidation of lipids. Antioxidant enzymes of the oxidoreductase class (superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO)) play an important role in the formation of the plant’s protective and adaptive reaction to stress. Therefore, the aim of our research was to study the change in the activity of superoxide dismutase, catalase, peroxidase and polyphenol oxidase in soybean seeds under conditions of fungal infection S. glycines. The studies were carried out in 2020. G. max seeds used in our research were of FSC “All-Russian Research Institute of Soybeans” breeding. The activity of superoxide dismutase and catalase was determined by spectrophotometric method; peroxidase and polyphenol oxidase activity - by colorimetric method; electrophoretic spectra of enzymes - by electrophoresis in a polyacrylamide gel. The protein content was determined by the Lowry method; malonic dialdehyde - by reaction with thiobarbituric acid. It was detected that the influence of the pathogen leads to an increase in the content of malonic dialdehyde, which indicates the occurrence of oxidative stress accompanied by a change in the specific activity of antioxidant enzymes of the oxidoreductase class, as well as a change in their multiple forms. Among the studied soybean varieties, only ‘Sentyabrinka’ had a low content of MDA (0.09 μmol/g of raw mass), which means that oxidative stress was insignificant. Moreover, we additionally noted a low specific activity of SOD (44.69 units/mg of protein), as well as a maximum decrease in the activity of POD (0.97 units/mg of protein) and PPO (0.30 units/mg of protein). The method of enzyme electrophoresis revealed high heterogeneity of SOD (from 6 to 12 forms) and POD (from 1 to 5); low heterogeneity of CAT and PPO (varies from 1 to 3 forms). The enzyme electrophoresis method revealed high heterogeneity of SOD (from 6 to 12 forms) and POD (from 1 to 5), low heterogeneity of CAT and PPO (from 1 to 3 forms). For the studied varieties of soybean, stable and steady forms of SOD11, SOD12, SOD14, CAT5, POD12, POD17, PPO14 enzymes were established. In infected soybean seeds, forms of SOD13, SOD15, CAT8, POD14 and PPO15 were found. They likely take an active part in the adaptive reactions of soybean to the effects of the studied biotic stress. High heterogeneity of SOD and POD, as well as sensitivity to external factors, allow using them as markers of adaptation to the pathogen S. glycines Hemmi