Phytotoxicity of silver nanoparticles and silver ions toward common wheat

Given the deficit of works describing the impact of silver nanoparticles (AgNPs) on the growth of crop plants, these studies were devoted to the determination of the influence of the surface properties of charge-stabilized AgNPs on induced phytotoxic effects. Three types of AgNPs of similar size distribution, but of diverse surface properties, were synthesized using trisodium citrate, sodium hexametaphosphate and tannic acid. The suspensions and solution of silver nitrate were applied in a hydroponic culture in order to assess their influence on the germination of Triticum aestivum seeds. Studies of the damage of the cell membrane and the activity of antioxidant enzymes were carried out on the shoots and roots of the seedlings. The differences in the plant condition were assessed while analyzing photosystem II. The results showed that the AgNPs stabilized with sodium hexametaphosphate exhibited a higher toxicity toward the tested plants than silver ions with the same concentration. It was found that the AgNPs obtained using tannic acid exerted an adverse effect on the crop plants. The citrate-stabilized AgNPs were the least toxic to the seedlings. The obtained results demonstrated that the surface properties of AgNPs strongly influence the phytotoxicity toward T. aestivum seedlings.