Abstract:
Oxidative enzymes catalyze the decomposition of reactive oxygen species: hydrogen peroxide, superoxide, hydroxyl
and singlet oxygen, which are formed during the normal plant physiological processes. The hydrogen peroxide is
decomposed by peroxidase and catalase along with superoxide dismutase. This research studies the activity of those
enzymes in potato leaves from plants subjected to thermo-hydric stress. The activity of oxidative enzymes studied had a
similar dynamic in the potato leaves. The highest activity was determined during budding phase, in which the leaves are
most sensitive to the action of thermo-hydric stress. All three enzymes analyzed had increased activity in the leaves of
plants grown at a 50% AHI hydric regime compared with those from the variants grown at 80% AHI regime. Under
thermo-hydric stress conditions the highest activity of catalase, peroxidase and superoxide dismutase was determined in
Robusta variety, which proved to be more sensitive to the action of these factors, and the lowest activity of those
enzymes was determined for Sante and Tresor varieties.
