Zinc oxide nanoparticles: a review of their biological synthesis, antimicrobial activity, uptake, translocation and biotransformation in plants

Over the past decade, incorporation of nanomaterials into agricultural practices like nanofertilizers and nanopesticides has gained a lot of attention. Progress and application of fertilizers in nanoforms are one of the effective options for considerable improvement of the agricultural yield worldwide. Zinc oxide nanoparticles (ZnO NPs) are considered as a biosafe material for biological species. Earlier studies have shown the potential of ZnO NPs in stimulation of seed germination and plant growth as well as disease suppression and plant protection by its antimicrobial activity. However, both positive and negative effects of ZnO NPs on plant growth and metabolism at various developmental periods have been documented. Uptake, translocation and accumulation of ZnO NPs by plants depend upon the features of NPs as well as the anatomy of the host plant. This review summarizes the applications of ZnO NPs as nanofertilizer in crop production and also attempts to examine and record the possible mechanism of antimicrobial activity of ZnO NPs. Biological synthesis of ZnO NPs and their uptake, translocation and biotransformation in plants via various routes have also been examined.