Plant Cell Wall Remodeling under Toxic Metal Stress: Structural Adaptation and Functional Implications

The plant cell wall plays a crucial part in cellular stress responses and acts as the first line of defense against harmful external circumstances. Sequestration of toxic metals in the cell wall is a key tolerance mechanism that enables plants to survive in contaminated environments. Despite recent advances, integrative approaches are needed to unravel the complex mechanisms of this protective interface in response to stress. The biosynthesis of polysaccharides like hemicelluloses and pectins and the resulting increase in cell wall thickening contribute to the cell wall's potential to immobilize toxic metals. This review offers an overview of recent findings on the modulation of specific cell wall activities that significantly impact the ability of plants to cope with metal toxicity. Moreover, it delves deeper into the structure and role of the cell wall components, revealing distinct patterns of lignocellulosic modifications and examining molecular and genetic approaches for their possible practical applications in biotechnological interventions. Strategic remodeling of cell wall components can enhance stress tolerance, optimize lignocellulosic traits, and improve environmental resilience. Ultimately, this review outlines the prospects of targeted gene editing in engineering plants with toxic metal stress tolerance, shifting the perspective of the cell wall from a passive structure to a powerful biotechnological tool for addressing real-world environmental challenges.