Title : The influence of ambient temperature on the MDA and H2O2 production and antioxidant metabolism in Hedera helix leaves. One year study
Abstract:
The cellular changes provoked by either high temperature or low temperature include reactions which lead to the excess accumulation of toxic compounds, especially reactive oxygen species (ROS). The consequence of ROS accumulation is oxidative stress. The main effects of ROS include autocatalytic peroxidation of membrane lipids and pigments, modification of membrane permeability and functions. Plants exposed to extreme temperatures use several non- enzymatic and enzymatic antioxidants to cope with the harmful effects of oxidative stress; higher activities of antioxidant defence enzymes are correlated with higher stress tolerance.
The plants in our region, where the climate is humid continental, are exposed to huge temperature oscillations. Hedera helix (Ivy) is one of those plants that successfully respond to sudden day-to-day temperature changes and not only during the yearly season change. The aim of our research was to detect the influence of ambient temperature on the MDA and H2O2 production and antioxidant metabolism in Hedera helix leaves throughout all four seasons (winter, spring, summer and autumn).
Leaves of five individual plants of the Hedera helix, were collected at the location Banj brdo (Banja Luka), Bosnia and Herzegovina, in the period from November 2017 to November 2018. Leaves were conserved in liquid nitrogen, from the moment of sampling to the moment of extraction in the laboratory. We have examined the speci?c activity of three antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). The content of total phenols, concentration of hydrogen peroxide (H2O2) and malondialdehyde (MDA) were also measured and examined during this one year study.
Results of our research showed that concentration and activity of the analysed parameters vary on the vegetation period and the ambient temperature. Each individual plant of these analysed reacts in a specific way. Activity of peroxidase and catalase was higher during the winter months when the temperature was lower, while their activity decreased and reached its minimum during the summer period. Level of total phenols was influenced by POD activity and level of H2O2 was in correlation with both peroxidase and catalase. Results have also showed that there are cyclic changes in concentration of plant pigments where we noticed that there is a significant interconnection of carotenoids on concentration of chlorophyll A and B, respectfully.
