Effect of Zinc Deficiency on Gene Expression and Antioxidant Enzyme Activity in Barley Plants at Optimal and Low Temperatures

In a controlled environment, the dynamics of the activity of two key antioxidant enzymes, superoxide dismutase (SOD) and peroxidase (PO), and the expression of its encoding genes (HvSOD1 and HvPRX07) were studied at the temperatures of 22 and 4?in barley plants growing at the optimal zinc content (2 mu M) in the substrate and its deficiency (0 mu M). It was found that at 22?, a zinc deficiency did not lead to an increase in the intensity of lipid peroxidation (LPO) in the barley roots and leaves, which correlates with an increase in the number of transcripts of the genes studied and an increase in the SOD and PO activity. Under hypothermia, metal deficiency caused an increase in oxidative processes in the roots of seedlings, which is associated with the absence of an increase in the activity of antioxidant enzymes, despite an increase in gene expression. At the same time, the intensification of oxidative processes did not occur in the leaves. The protection of leaf cells from oxidative stress under combined action of zinc deficiency and low temperature may be associated with an increase in the activity of other (nonenzymatic) components of the antioxidant system.