Dynamics of SOD activity and accumulation of TBA-active products in the process of ontogeny of some sod-forming plants in a megalopolis

Abstract

In the conditions of a modern metropolis, green spaces are an integral planning structure, which the issues of not only improving the aesthetics of the city's architecture, but also improving the environmental safety of the population are solved. Lawn grasses play a significant role in improving the microclimate of urban areas; the harmful concentration of gases in the air decreases, the regulation of the thermal regime and humidity is observed. Since almost half of the urban area is occupied by sod-forming plants, it is relevant to study the resistance of these species to anthropogenic impact in an urbanized environment. The aim of the work was to assess the state of the antioxidant system, namely the activity of superoxide dismutase (EC 1.15.1.11), and the accumulation of TBA-active products in the process of ontogeny of sod-forming plants growing in a metropolis. The objects of the study were Setaria viridis (L.) Beauv.) and Elytrígia répens (L.) Nevski.). It has been established that due to oxidative stress caused by vehicle emissions and industrial aeropollutants, there is an intensification of lipid peroxidation processes in the vegetative organs of Setaria viridis, Elytrigia repens during all phases of ontogeny. According to the results of the research, it was found that Elytrigia repens was more stable in terms of the content of TBA-active products (the level of the indicator in leaves was 30–50 %, roots – 20–44 % higher than the control indices) compared to Setaria viridis, for which the excess was 50–70 % (leaves) and 40–62 % (roots). SOD activity is an indicator of resilience to stressors and varies with the duration and intensity of stressors. The obtained results indicate that the enzyme activity of experimental plants in the generative state (increase in enzyme activity by 47.5–38 % in Elytrigia repens, by 74–62.5 % in Setaria viridis) in contaminated areas was higher than in virginile individuals (SOD activity levels: Elytrigia repens (37.5–26.5 %), Setaria viridis (60–50 %). The presence of close correlations between the activity of SOD and the content of TBA-active products characterizing the adaptive potential of plant organisms in the vegetative organs of the studied species was established.