The response of the antioxidant system of wheat sprouts to irradiation of seeds with UV light

The response of the antioxidant system of sprouts of wheat Triticum aestivu m L. to preliminary irradiation of seeds with UV light was studied. The dep endence of lipid peroxidation and the extent of antioxidant activity on the duration of irradiation was studied. It was shown that low doses of UV rad iation (5-15 min) stimulate the antioxidant protection of green wheat sprou ts grown for eight days. Increasing the irradiation time to 30-60 min leads to the inhibition of lipid peroxidation by the antioxidant system. A more prolonged irradiation of seeds with UV light (for 1-6 h) led to an increase in the level of lipid peroxidation in sprouts, However, 1-2-day-old sprout s from seeds irradiated for 5-6 h, adapted themselves to the influence due to the compensatory mechanisms, By the 8th day of germination of preliminar ily irradiated seeds, the content of antioxidants and malone dialdehyde ret urned to the norm. The dynamics of activity of peroxidase in seeds irradiat ed with low doses of UV light for 30 min was studied, It was found that on the third day of seed germination, a decrease in peroxidase activity follow ed by its slight increase occurred. The maximum activity of the enzyme in t he endosperm was observed on day 5-6, and in roots and green sprouts, on da y 3-5 of germination. It was concluded that antioxidants and peroxidase are involved in the compensatory mechanisms of inhibition of free radicals for med upon UV irradiation of seeds.