Cytological and Molecular Effects of Silver Nanoparticles (AgNPs) on Vicia faba M1 Plants

Abstract

Silver nanoparticles (AgNPs) are among the most widely used nanoparticles and are found in various types of products. In the past few years, these nanoparticles have received significant attention as pesticides for agricultural applications. Utility of AgNPs as efficient pesticides would become a reality if the researches provided some understanding of toxicity of these nanoparticles. Evaluation of the potential genotoxic effects of AgNPs on Vicia faba M1 plants was the main goal in this study. Seeds of V. faba (Sakha 1 variety) were treated with three concentrations of AgNPs (25, 50 and 75 ppm) and M1 populations raised from these seeds were investigated at different levels. Results indicated that all the three concentrations were able to induce significant increase in seed germination percentage (G) and germination rate index (GRI) in addition to root length and seedling vigor index (SVI) compared to control, while no significant differences were detected among the three AgNPs concentrations and control for shoot length. The maximum germination percentage (99.00 %) was found at the 50 ppm concentration while the highest values of root length (15.57 cm) and seedling vigor index (43.77) were recorded at the 25 ppm concentration. Cytological analysis showed that only the concentration of 25 ppm significantly reduced mitotic index (83.47 %) compared to control (91.38 %). Moreover, all treatments caused significantly increase in the percentage of abnormal cells, while the lower concentration (25 ppm) induced the highest percentage of abnormalities (6.90 %) compared to the other treatments. On the molecular level, the effects of AgNPs on genomic template stability (GTS) were measured based on RAPD-PCR analysis using 16 arbitrary primers. All AgNPs concentrations caused reduction in GTS % values; compared to control, which showed decrease in GTS % values as AgNPs concentrations increased. These results indicated that AgNPs had toxic effects on V. faba M1 plants at cytological and molecular levels.