Melatonin-Mediated Alleviation of Heavy Metal Toxicity in Horticultural Crops

Abstract

Human activities have caused heavy metal (HM) pollution to become a major agricultural and environmental challenge worldwide. Scientists worldwide investigate strategies to decrease the toxicity of HMs in agricultural land and their detrimental effects on plant growth. Melatonin (MT), a multifunctional molecule with strong antioxidant properties, has gained recognition as a stress-alleviating agent that works particularly well against HM-induced stresses.  MT functions as a recently recognized signaling molecule and plant growth regulator that plays an essential role in strengthening plant resistance against abiotic stress. MT effectively mitigates HM stress in horticultural crops as scientists identify it as a promising solution to manage HM contamination in plant species. The review article evaluates MT's function in decreasing HM toxicity levels in horticultural plants through the identification of associated physiological, biochemical, and molecular mechanisms and minimizing rhizosphere HM concentrations and MT-mediated metal sequestration while maintaining nutrient levels and activating defense systems and hormone pathway involvement. This review article establishes a theoretical framework for regulating HM ion accumulation in horticultural plants grown in contaminated soils.