Effect of ZnO and CeO2 nanoparticles on the element accumulation, growth and biochemical parameters in <i>Phaseolus vulgaris</i> L.

Contamination of soils with oxide metals nanoparticles, by various human activities, is an important environmental issue in both developing and developed countries. The aim of the present study was to investigate the effects of ZnO and CeO2 NPs (250, 500, 1000 and 2000 mg L-1) on some growth and biochemical parameters of bean plants growing under greenhouse conditions in a completely randomized design. The results indicated that ZnO NPs almost, at all concentrations, enhanced plant height, while CeO2 NPs at high concentration did not. Both NPs at all concentrations decreased chlorophyll and anthocyanin content in the experimental plants compared to control ones. There was no significant differences in total protein content in both treatments compared to control. However, a protein band with molecular weight of 28 KDa seems to be appeared in the group treated by 500 mg L-1 ZnO NPs. The activity of antioxidant enzymes in CeO2 NPs-treated plant was higher than those in ZnO NPs treatments. Altogether, the results showed that plant responses to CeO2 NPs were more subject to change upon to concentration than ZnO NPs.