The role of nanoparticles and nanotechnologies in regulating metal(loid) accumulation in rice (Oryza sativa L.) and wheat (Triticum aestivum L.)

Metal(loid) contamination is a significant threat to environmental health and agricultural productivity, as it can cause toxic elements such as lead, arsenic, or cadmium to accumulate in plants and enter the food chain. In recent years, the use of nanoparticles (NPs) and other approaches in nanotechnology has become a viable solution to this problem. Several mechanisms can be utilized by nanoscale materials to control plant metal (loid) accumulation, such as complexation of metal ions, transformation of toxic metals into more manageable forms, immobilization of harmful contaminants in the soil for preventative use, and modification of physiological pathways for improving plant tolerance. In this review, a comprehensive analysis of engineered nanoparticles, including metal-based NPs (e.g. iron oxide, zinc oxide), carbon-derived nanomaterials like graphene oxide and carbon nanotubes, and hybrid nanocomposites, is presented to illustrate their roles in controlling the uptake/translocation and detoxification of metal(loid)s in plants. The paper underscores the environmental consequences of nanoparticle usage, such as possible toxicity and ecological survival, while also highlighting important knowledge shortcomings, including the necessity for extended research or fieldwork. Additionally, the article culminates with a list of suggested research paths for enhancing the safe and effective application of nanotechnologies in sustainable agriculture and environmental remediation. Consistent with the scope of the available mechanistic evidence, the review focuses specifically on the two most widely cultivated staple cereals, rice ( Oryza sativa L.) and wheat ( Triticum aestivum L.), which together account for the majority of dietary metal(loid) exposure through cereal grain worldwide, and draws on Arabidopsis thaliana only as a model system for resolving the underlying molecular mechanisms.