ANATOMICAL AND PHYSIOLOGICAL CHANGES IN CROP PLANTS EXPOSED TO HEAVY METAL CONTAMINATION

Abstract

Heavy metal contamination threatens crop productivity by altering plant structural development, physiological balance, and metal uptake behavior. This study evaluated anatomical and physiological changes in maize exposed to cadmium contaminated soil using a secondary quantitative dataset from an amendment-based phytoremediation experiment. Maize was assessed across control and treatment groups using organ-level anatomical indicators, physiological stress markers, cadmium accumulation variables, and extraction efficiency. Anatomical responses were represented by shoot biomass, root biomass, total biomass, and root–shoot allocation, while physiological responses were evaluated through malondialdehyde, superoxide dismutase, catalase, and peroxidase activities. Results showed that amendment treatments substantially improved maize growth compared with the control. AG1 produced the highest total biomass, shoot cadmium concentration, extraction efficiency, and catalase activity, indicating the strongest combined anatomical and physiological response. G2 showed the lowest malondialdehyde level, suggesting reduced lipid peroxidation, while GG2 showed the highest peroxidase activity. Correlation analysis showed that extraction efficiency was strongly associated with catalase activity, cadmium translocation factor, shoot cadmium concentration, and shoot biomass. These findings indicated that successful cadmium extraction depended on coordinated biomass production, antioxidant defense, and metal movement into above-ground tissues. Maize exhibited clear organ-level anatomical and physiological adjustments under cadmium contamination, with AG1 identified as the most effective treatment for improving growth, stress tolerance, and phytoremediation performance.