Effects of Silicon Nanoparticles on the Activity of Antioxidant Enzymes in Tomato Roots Invaded by Meloidogyne incognita (Kofoid et White, 1919) Chitwood, 1949.

The effect of silicon nanoparticles (1 µg/mL) on the activity of lipid peroxidation, peroxidase, superoxide dismutase, and catalase in tomato roots invaded by root-knot nematode Meloidogyne incognita was studied. It was shown that, at the early stages of parasitization in the plants treated with Si-NPs, a low activity of PO and SOD, as well as an increased level of lipid peroxidation, are observed, which indicates the formation of free radicals (reactive oxygen species, ROS) that can inhibit nematodes and limit the formation of giant cells. During the sedentary stage, at the stages of nutrition, development, and egg production, the roots of the treated plants showed an increased activity of PO, CAT, and SOD, as well as a low activity of LPO as compared to the infested untreated plants. This makes it possible to maintain a balance between the formation and neutralization of ROS and is important not only in the protection of plant tissues from oxidative processes but also in the preservation of giant cells that feed the parasite. The presented data for the first time show the mechanism of action of Si-NPs in the development of resistance and adaptation of plants to biogenic stress, associated with the effect on various components of the antioxidant system and their functional interaction.