Phytotoxic and genotoxic effects of ZnO nanoparticles on garlic (Allium sativumL.): A morphological study

Abstract

The effects of zinc oxide nanoparticles (ZnO NPs) on the root growth, root apical meristem mitosis and mitotic aberrations of garlic (Allium sativum L.) were investigated. ZnO NPs caused a concentration-dependent inhibition of root length. When treated with 50 mg/L ZnO NPs for 24 h, the root growth of garlic was completely blocked. The 50% inhibitory concentration (IC(50)) was estimated to be 15 mg/L. The mitosis index was also decreased in a concentration- and time-dependent manner. ZnO NPs also induced several kinds of mitotic aberrations, mainly consisted of chromosome stickiness, bridges, breakages and laggings. The total percentage of abnormal cells increased with the increase of ZnO NPs concentration and the prolongation of treatment time. The investigation provided new information for the possible genotoxic effects of ZnO NPs on plants.

Zinc-Induced Genotoxic Effects in Root Meristems of Barley Seedlings

“…In Zn acetate treated variants, a descending trend from 10 µM to 250 µM was noticed, followed by a MI increase at the maximum tested concentration. Whereas some previous studies (El-Ghamery et al, 2003;Shaymurat et al, 2012) revealed a dose-dependent inhibition of MI in Zn treatments, Somesh et al (2005) confirmed the mitodepressive potential of Zn acetate and Zn sulphate only at concentrations over 500 ppm, while the lower concentrations, comparable with those tested in our study, stimulated MI.…”

“…Some reports state that high Zn concentrations are not strongly genotoxic (Codina et al, 2000;Gómez-Arroyo et al 2001;Marcato-Romain et al, 2009). The aneugenic and clastogenic action of Zn was also evidenced in other species like wheat, black cumin, onion, sugarcane (El-Ghamery et al, 2003;Jain et al, 2010;Shaymurat et al, 2012;Somesh et al, 2005), but a connection between Zn concentration and aberration frequency was not always noticed.…”

Interactions between nanoparticles and plants: phytotoxicity and defense mechanisms

“…DNA molecule is a cell's genetic material and any damage to the DNA would cause changes in the encoded proteins, which may result in malfunctions and/or complete inactivation of the encoded proteins. Enhanced DNA degradation has been observed in plants exposed to kinds of environmental stresses such as metal-based NPs and carbon nanomaterials (López-Moreno, de la Rosa, Hernández-Viezcas, Castillo-Michel, et al 2010;Shen et al 2010;Kumari et al 2011;Khodakovskaya et al 2012Khodakovskaya et al , 2013Shaymurat et al 2012;Dimkpa et al 2013). For instance, López-Moreno, de la Rosa, Hernández-Viezcas, Castillo-Michel, et al (2010) discovered that high concentrations of CeO 2 NPs had negative effects on DNA of G. max.…”

Cytotoxic and apoptotic activities of extract of Amaranthus spinosus L. in Allium cepa and human erythrocytes

“…Subsequently, the root tips were rinsed with distilled water and imaged (Shaymurat et al 2012). In addition, 10 root tips were excised from each bulb and the colored complex triphenyl formazan was extracted in 95% ethanol.…”