Deciphering ways of heavy metals toxicity reduction in crop plants.
Heavy metal (HM) pollution is a major environmental issue affecting ecosystems worldwide. Human activities such as agriculture, mining and industrial manufacturing expose ecosystems and living organisms to HM contamination. HM-contaminated soils impair crop productivity, disrupt food chains and pose serious risks to human health. In plants, HMs interfere with biomolecular and physiological processes leading to morphological and structural alterations. To tolerate HM-induced stress, plants activate various signaling pathways including calcium/calmodulin, MAPK and hormone signaling which regulate the expression of stress-responsive genes. The role of microRNAs (miRNAs) in mitigating metal toxicity has gained considerable attention in recent years. Conventional methods for removing contaminants from soil and water are often expensive, inefficient and environmentally harmful. Phytoremediation has therefore emerged as an eco-friendly and sustainable approach for HM detoxification and environmental restoration. This review provides an overview of HM toxicity, its major sources, uptake mechanisms and adverse environmental effects. It further discusses the relationship between HM stress and plant signaling pathways, the regulatory role of miRNAs and phytoremediation-based strategies for HM alleviation, highlighting recent advances, current challenges and future prospects.