Influences of zinc oxide nanoparticles on Allium cepa root cells and the primary cause of phytotoxicity

Research Article Zinc oxide nanoparticles at environmentally relevant concentrations cause cytotoxic and chromosomal damage to <i>Allium</i> <i>cepa</i> root cells

“…The disturbance of clumped chromosomes in CAs was the most frequent anomaly in the metaphase and in the anaphase, respectively. Although this outcome is a counterpoint to results recorded by Sun et al (2019) and Kumari et al (2011), who found that chromosome stickiness was the most frequent CA, it corroborates the high DNA fragmentation increase observed in the comet assay carried out by Sun et al (2019) and Ghosh et al (2016) with A. cepa specimens. Ghosh et al (2016) reported that most CAs were laggard and bridge chromosomes (anaphase and telophase), which suggests the involvement of the mitotic spindle.…”

“…Different environmentally relevant concentrations of ZnO nanoparticles (NPs) led to cell damages and to behavioral dysfunctions in the chromosomes of meristematic cells in the roots of A. cepa. The A. cepa model is simple and efficient to evaluate the toxic effects of several contaminants, such as high and low concentrations of NPs (Kumari et al, 2009;Modlitbová et al, 2018;Sun et al, 2019), in short-run exposure assays.…”

“…Zinc can cause phytotoxicity and, consequently, serious morphophysiological and cell damage at inappropriate concentrations. Previous studies have shown the cytotoxic and genotoxic damages caused by progressive Zn accumulation and distribution in the cytoplasm and nucleus of A. cepa (Kumari et al, 2011;Sun et al, 2019) and Vicia faba cells (Ghosh et al, 2016) after to exposure to high concentrations of ZnO NPs. Based on the present results, we can assume that low increase in accumulated Zn rates after the exposure to very low concentrations of ZnO NPs can have significant biological effect on plants and animals (Mesak et al, 2018;Souza et al, 2018).…”

“…Ghodake et al (2011) found that ZnO NPs blocked the growth stages of A. cepa roots due to their accumulation in the root system, as well as caused severe damages at cell and chromosomal level. Sun et al (2019) demonstrated the adverse effects of toxicity in A. cepa, among them one finds root-development inhibition, membrane-integrity loss, decreased metabolic activity, DNA damage and cell death. These effects were caused not only by Zn 2+ released by ZnO NPs, but by the NPs themselves.…”

Zinc Oxide Nanoparticles Damage Tobacco BY-2 Cells by Oxidative Stress Followed by Processes of Autophagy and Programmed Cell Death

“…On the other hand, the ZnO NPs toxicity is closely connected with changes in intracellular calcium ions and the interactions with biomembranes and some organelles, mainly mitochondria, were also reported [ 25 , 27 ]. ZnO NPs induced genotoxicity which is connected with changes in DNA, chromosomal aberration and structural changes of nucleus [ 28 ]. Zinc oxide nanoparticles in an aqueous solution under UV radiation have a phototoxic effect based on the production of H 2 O 2 and O 2− reactive oxygen species.…”