Implications of Heavy Metal on Legume-Microbes and Accumulation in Plants

Abstract

Heavy metal contamination represents a critical environmental challenge because of its substantial risks to both human health and ecosystem stability. Phytoremediation, which relies on plants and associated microorganisms to remove or immobilize pollutants, has therefore received increasing research attention in recent years. Microbial inoculants, including endophytic fungi and rhizobia, have been shown to enhance phytoremediation efficiency in both legumes and cereals. External amendments such as indole-3-acetic acid and biochar further improve soil physicochemical properties, stimulate plant growth, and reduce heavy metal uptake. Plant growth-promoting rhizobacteria also mitigate metal-induced toxicity by enhancing plant stress tolerance and physiological resilience. Evidence indicates that co-inoculation with plant growth-promoting rhizobacteria and rhizobia markedly strengthens the capacity of leguminous plants to remediate contaminated soils, offering a promising strategy for sustainable land rehabilitation. Collectively, these findings deepen understanding of plant–microbe–metal interactions and highlight the potential of integrated biotechnological approaches for effective soil restoration.