Zinc and nano zinc mediated alleviation of heavy metals and metalloids in plants: an overview.

Heavy metals and metalloids (HMs) contamination in the environment has heightened recently due to increasing global concern for food safety and human livability. Zinc (Zn²⁺) is an important nutrient required for the normal development of plants. It is an essential cofactor for the vital enzymes involved in various biological mechanisms of plants. Interestingly, Zn²⁺ has an additional role in the detoxification of HMs in plants due to its unique biochemical-mediating role in several soil and plant processes. During any exposure to high levels of HMs, the application of Zn²⁺ would confer greater plant resilience by decreasing oxidative stress, maintaining uptake of nutrients, photosynthesis productivity and optimising osmolytes concentration. Zn²⁺ also has an important role in ameliorating HMs toxicity by regulating metal uptake through the expression of certain metal transporter genes, targeted chelation and translocation from roots to shoots. This review examined the vital roles of Zn²⁺ and nano Zn in plants and described their involvement in alleviating HMs toxicity in plants. Moving forward, a broad understanding of uptake, transport, signalling and tolerance mechanisms of Zn²⁺/zinc and its nanoparticles in alleviating HMs toxicity of plants will be the first step towards a wider incorporation of Zn²⁺ into agricultural practices. Heavy metals and metalloids pollution in the environment, particularly in soils, has gained increased attention globally. Zn²⁺ is a crucial nutrient for tolerance against heavy metals. This review illustrates the vital role of Zn²⁺ and nano Zn in plants and explains the knowledge of their impact in alleviating HMMs toxicity in plants. [ABSTRACT FROM AUTHOR]