Nanoparticles Enhance Antioxidant System and Improve Yield Quality of Sugar Beet (Beta vulgaris L.) Plants Irrigated with Wastewater

IN DEVELOPED and low-economy countries, water scarcity due to climate change and rapid population growth has led to reuse of untreated wastewater in the agricultural sector resulting in oxidative stress in plants. The oxidative stress tolerance of sugar beet, the second most important sugar producing plant economically, can be improved by applying novel nanotechnology. A field experiment was conducted to investigate the effect of application of different doses (control; 0.0, 50, 100 and 200 mg. L-1) of SiO2, MgO and a mixture of SiO2 + MgO NPs in improving the growth and yield quality of sugar beet plants irrigated with wastewater. Low dose (50 mg.L-1) of SiO2 + MgO NPs resulted in the highest improvement in root length and diameter, but MgO NPs was the best in improving FM and DM by about 187 and 277.2 %, respectively. Application of high level of (200 mg.L-1) SiO2 and MgO NPs affect root parameters and pigments pools negatively. The results showed that 50 mg.L-1 of SiO2 NPs was the best at enhancing the activity of CAT, POX, PPO and APX in leaves by about 151.7, 139.1, 175.9 and 213.9 % greater than untreated leaves. In long term effect, 100 and 200 mg.L-1 of NPs were more effective in improving the morphological characteristics of root and the maximum increase in crop quality was enhanced by 200 mg.L-1 of SiO2 NPs. It was concluded that MgO NPs improved total Chl content and sucrose accumulation in leaves, while SiO2 NPs treatments were the best in improving antioxidant enzyme activities and ameliorated the oxidative stress and in the long-term effect in improving the crop quality of sugar beet plants and enhancing sucrose accumulation in roots.