Effect of Low Temperature on the Intensity of Oxidative Processes and the Activity of Antioxidant Enzymes in Wheat Plants at Optimal and Excessive Zinc Concentrations in the Root Medium

Abstract

The effects of low temperature (4°C) on the rate of lipid peroxidation and activities of superoxide dismutase and peroxidase in the roots and leaves of winter wheat (Triticum aestivum L.) plants were determined under laboratory conditions. The root medium contained the optimal (2 μM) zinc concentrations or high ones (1000 μM). It was found that, under optimal mineral nutrition, such cooling did not intensify the oxidative processes in the wheat leaves and temporarily increased them in the roots. This witnesses to the successful cold acclimation of the plants. At an excessive zinc concentration, the exposure to low temperature enhanced lipid peroxidation in both the roots and the leaves. This effect might be, to some extent, accounted for by rather weak activities of said antioxidant enzymes and incoordination of their functions in the chilled plants. In general, the revealed attenuation of the plant capacity to sustain the cellular redox balance under a joint impact of the applied stress-factors entails oxidative stress and stronger growth inhibition that, as a result, negatively affects the plants’ viability.