impact of cadmium on root growth and ascorbate peroxidase activity (apx) and catalase activity (cat) in wheat (triticum aestivum)

Cadmium (cd) is recognized as a major environmental pollutant that, upon absorption by plants, disrupts various physiological processes, leading to significant stress. this study investigates the effects of different cd concentrations on root growth parameters and antioxidant enzyme activities in soft wheat (triticum aestivum). treatments with 50 and 100 mg/l cd reduced root biomass by 28.70% and 30.91%, respectively, compared to the control. the tolerance index (ti) peaked at 80% under 50 mg/l cd but declined to 50% at 100 mg/l, indicating moderate tolerance at lower cd levels. exposure to higher cd concentrations (200 and 500 mg/l) resulted in biomass reductions of 95% and 80%, respectively, demonstrating severe toxicity. antioxidant enzyme analysis revealed that ascorbate peroxidase (apx) activity was stimulated across all cd treatments, while catalase (cat) activity exhibited a non-linear response to increasing cd concentrations. overall, cadmium exposure negatively affected root development in wheat by impairing physiological mechanisms and inducing oxidative stress.