Mitigating Effect of -Zeatin on Cadmium Toxicity in .

Phytohormones, particularly cytokinin -zeatin (Z), were studied for their impact on the green alga under cadmium (Cd) stress, focusing on growth, metal accumulation, and stress response mechanisms. Using atomic absorption spectroscopy for the Cd level and high-performance liquid chromatography for photosynthetic pigments and phytochelatins, along with spectrophotometry for antioxidants and liquid chromatography-mass spectrometry for phytohormones, we found that Z enhances Cd uptake in , potentially improving phycoremediation of aquatic environments. Cytokinin mitigates Cd toxicity by regulating internal phytohormone levels and activating metal tolerance pathways, increasing phytochelatin synthase activity and phytochelatin accumulation essential for Cd sequestration. Treatment with Z and Cd also resulted in increased cell proliferation, photosynthetic pigment and antioxidant levels, and antioxidant enzyme activities, reducing oxidative stress. This suggests that cytokinin-mediated mechanisms in enhance its capacity for Cd uptake and tolerance, offering promising avenues for more effective aquatic phycoremediation techniques.