The versatility of green synthesized zinc oxide nanoparticles in sustainable agriculture: A review on metal-microbe interaction that rewards agriculture

The integration of nanotechnology in the realm of agriculture, specifically through the utilization of nanofertilizers and nanopesticides, has been a topic of increasing interest in recent years. The application of fertilizers in the form of nanoparticles is one of the most promising solutions for the significant enhancement of agricultural production worldwide. This review highlights the versatility of green synthesized zinc oxide nanoparticles (ZnONPs) in sustainable agriculture and their interactions with plant-microbe systems. ZnONPs have been classified as a biosafe substance for biological species. Previous research has revealed the efficacy of ZnONPs in the induction of seed germination and plant growth, as well as its potential for biological control through its antimicrobial activities. However, it is important to note that the effects of ZnONPs on plant growth and metabolism can vary depending on the developmental phase of the plant. Furthermore, the uptake, transport and aggregation of ZnONPs by plants are dependent on the characteristics of the NPs and the morphology of the host plant. However, the use of ZnONPs in agriculture also poses some potential adverse effects, including toxicity to non-target organisms, accumulation in the food chain, and environmental pollution. These effects are influenced by various factors such as particle size, concentration, and exposure time. Thus, the review discusses the current knowledge on the toxicity and environmental impact of ZnONPs in agriculture and their potential mitigation strategies. Furthermore, this review aims to comprehensively highlight the potential applications of ZnONPs as a nanofertilizer in crop production, as well as to explore and understand the possible mechanisms of its antimicrobial activity. Additionally, the biological production of ZnONPs, its absorption, transport mechanisms, phytoremediation of heavy metals in plants and toxicity studies are also investigated.