S11 - Session P3 - Influence of silica nanoparticles on the enzymatic and non-enzymatic antioxidant activity of green pea (Pisum sativum L.) affected by drought

Authors: Ruta Sutuliene *, Jurga Miliauskiene, Lina Rageliene

Abiotic stress caused by drought impairs plant growth and reduces yields. The impact of silica nanoparticles (SiO 2 NPs) has been researched through the adverse effects of drought on the growth, oxidative stress, and antioxidative response of pea 'Respect', in this study. The research was carried out in a greenhouse with a natural day length photoperiod. At the 40 BBCH growth stage pea plants were watered (100+-1 mL per pot) or foliar sprayed (ca. 14+-0.5 mL plant-1) with suspensions containing SiO 2 NPs (0, 12.5ppm, 25 ppm, and 50 ppm) and were exposed to drought stress for 10 days. The moisture content of the substrate of drought-affected plants was maintained at 30% and that of non-drought-affected plants at 80%. At drought stress, peas treated with SiO 2 NPs (50 ppm) increased their relative water content, specific leaf area, and decreased root/shoot ratio as compared to plant non-treated with SiO 2 NPs. In addition, spraying or watering of SiO 2 increased peas tolerance to drought by increasing the activity of antioxidant enzymes including catalase, ascorbate peroxidase, glutathione reductase, and superoxide dismutase, as well as reducing hydrogen peroxide and lipid peroxidation in plant tissue. It was observed the increase in total phenolic compounds and non-enzymatic antioxidant activity (DPPH, ABTS, FRAP) in peas treated with SiO 2 NPs under drought stress. Thus, our results support the positive role of SiO 2 NPs application, especially the absolute role of 50 ppm SiO 2 NPs, in managing the detrimental effects of drought stress on pea plants.