Influence of growing conditions on the activity of ascorbate oxidase and polyphenol oxidase in leaves of woody plants

The paper presents research on the identification of species features in native species of woody plants growing in plantations with different intensities of anthropogenic stress. It is shown that the local growth conditions affect the activity of the ascorbate oxidase and polyphenol oxidase enzymes. The objects of the study were the native species Acer platanoides L. and Betula pendula Roth. When determining the features of the dynamics of enzyme activity, the level of environmental pollution and local conditions of the growing site were taken into account. For this purpose, sample plots 1 and 2 were determined. These sample plots differed in microrelief and, as a consequence, abiotic parameters of plant growth conditions. Sample plots in elevated, blow areas with a leveled surface were indicated as sample plot 1. Sample plots within each type of planting in areas with lower relief were indicated as sample plot 2. Higher values of relative humidity and lower temperatures of soil and atmospheric air were observed on sample plots 2. The activity of ascorbate oxidase and polyphenol oxidase do not react the same way to different levels of environmental pollution and local growth conditions within the type of plantations. Ascorbate oxidase activity was species specific. In B. pendula, the activity of ascorbate oxidase in control plantations on sample plot 2 was significantly higher than on sample plot 1. In A. platanoides, the nature of the enzyme activity changed during the growing season within the sample plots. In the plantations of sanitary protection zones and linehaul plantings, on the contrary, higher values were noted on sample plot 1. In urban plantation, the activity of polyphenol oxidase in the leaves of the studied species of woody plants by August had significantly higher values compared with control plantation. The activity of polyphenol oxidase in the studied trees had common features.