Abstract
The aim of this work was to study the toxicity of nanosheet zinc oxide nanoparticle with the size of 45 nm. The penetration of nanoparticles at an exposure by a localized spray does not make it possible to understand the mechanism of transport and bioavailability of the nanoparticles. In contrast, nanoparticles penetrated, via the roots, as a function of their diameter, the smaller ones having caused leaf stress (by translocation) at low concentrations. So that the choice of method of root application. Plants treated with 50 mg L-1 of ZnO-NPs presented disturbance in leaf due to changes in chlorophyll's biosynthesis. The highest value of the photosynthetic pigments was recorded at 5 mg L-1 of ZnO-NPs. However, the treatment with 50 mg L-1 of ZnO-NPs caused a decrease in the levels of chlorophyll a and b. Moreover, ZnO-NPs leaves significantly enhanced antioxidant enzymes activities.