Effect of zinc oxide nanoparticles on Triticum aestivum L. and bioaccumulation assessment using ICP-MS and SEM analysis

Abstract

The impact of zinc oxide nanoparticles (ZnONPs) on Triticum aestivum L. has been explored in this study. The wheat seedlings were allowed to grow on Hoagland and Knop agar medium supplemented with different concentrations of ZnONPs (2500, 5000, 7500, 10,000, and 15,000 ppm) for three weeks. To determine their effect, the growth parameters, viz., wheat seed germination, seedling growth, and chlorophyll content, were taken into consideration. Moreover, the bioaccumulation of ZnONPs in root cellswasdetermined by means of SEM, and zinc content in ZnO NP treatedseedlingswasmeasured byICP-MS. The abatement in seed germination was observed at allconcentrations of ZnONPs used,exceptat 2500 ppm. The plantgrowthand chlorophyllcontent also declined with an increase in ZnONPsconcentration, exceptat 2500 ppm. The maximum reduction in shoot height (23.7%), root length (66.8%), seedling fresh weight (33.8%), and dry weight (54.8%) was noticed at the highest concentration of ZnONPs (15,000 ppm). At 15,000 ppm of ZnONPs, the chlorophyll a, chlorophyll b, andtotalchlorophyll were reduced by 80.6%, 74.2%, and 78.5%, respectively. An elevation in Zn concentration was noticedwith an increase in the concentration as revealed by the ICP-MSanalysis. The TEM micrographs exhibit the accumulation of ZnONPswithin theroot cellsof wheat seedlings treated with ZnONPs (15,000 ppm). Thus, nanoparticles may have a destructive effect on the plant, and therefore their considerate use is advisable.