Plants and rhizospheric environment: Affected by zinc oxide nanoparticles (ZnO NPs). A review

Nowadays, there are many critical concerns in the agricultural sector, including reduced productivity of plants due to various environmental factors. Hence, a continuous innovation of existing technologies is necessary. Among the available technologies for sustainable agriculture, nanotechnology is one of the more promising technologies and has a great scope for development in agriculture. Zinc oxide nanoparticles (ZnO NPs) have attracted much attention due to their good properties and can be put into agriculture as nano-fertilizers, nano-growth regulators and nano-pesticides, although much remains to be explored about their mechanisms. Here, we review the literature on the interaction of ZnO NPs with plants through (i) uptake and transport pathways of ZnO NPs in plants. (ii) The mechanisms involved in improving growth, development and resistance. (iii) their effects on the rhizospheric environment. (iv) The toxic effects and mechanisms in plants. Our major conclusions are as follows: (1) they can be absorbed by the plant through the roots and leaves, with subsequent transformation. (2) moderate application can promote plant growth and mitigate stress, while excessive application can produce toxic effects. (3) the effects of them on the rhizospheric environment cannot be ignored. This study may provide a reference for the safe and effective use of ZnO NPs in agricultural production.