Mechanistic insights into heavy metals detoxification and signaling in plants: Molecular coordination and stress tolerance an updated overview

The contamination of plants with heavy metals (HMs) represents a significant threat to agricultural sustainability, severely impairing plant growth, physiology, and productivity through toxic effects. To withstand and adapt to metal stress, plants have evolved intricate defense systems encompassing morphological, physiological, biochemical, and molecular responses. This review synthesizes current understanding of metal uptake, translocation and cellular compartmentalization with emphasis on detoxification pathways such as chelation by metallothioneins and phytochelatins, organic acid exudation and the roles of metal transporters and regulatory proteins. We further highlight the regulatory influence of key transcription factors, including WRKY, MYB, and NAC families, which orchestrate complex gene networks underlying metal tolerance. Advances in proteomic and metabolomic studies have revealed transiently expressed proteins and dynamic metabolic shifts that underpin enhanced resilience under metal exposure. In addition, we examine emerging phytoremediation techniques and cutting-edge biotechnological strategies that offer promising avenues to boost plant tolerance and remediation efficiency. Looking ahead, future research should aim to unravel the intricate signaling cascades and transcriptional regulatory cascades governing metal stress responses, ultimately paving the way for the development of genetically engineered crops capable of sustaining productivity and supporting environmentally responsible remediation practices.