TY  - JOUR
AU  - Gupta, Siddhi
T1  - Impact of Zinc Stress on Antioxidant Enzyme Dynamics in Soybean
JO  - Journal of Stress Physiology & Biochemistry
Y1  - 2026/june
VL  - 22
IS  - 2
SP  - 63
EP  - 68
UR  - http://www.jspb.ru/issues/2026/N2/JSPB_2026_2_63-68.pdf
KW  - Zinc toxicity
KW  - antioxidant enzymes
KW  - soybean
KW  - oxidative stress
KW  - catalase
KW  - superoxide dismutase
KW  - peroxidase
KW  - glutathione reductase
KW  - ascorbate peroxidase
U1  - 1997-0838
N2  - A controlled pot experiment was conducted to evaluate the effects of graded concentrations of zinc sulphate (ZnSO₄·7H₂O) on the antioxidant defense system of soybean (Glycine max L.). Soil was amended with zinc at 0 (control), 250, 500, 750, 1000, and 1250 mg kg⁻¹, and enzymatic responses were assessed at pre-flowering (30 days), peak-flowering (45 days), and post-flowering (60 days) stages under triplicate conditions. A significant enhancement in antioxidant enzyme activities was observed with increasing zinc concentration up to 1000 mg kg⁻¹. Maximum activities of catalase (4.945, 5.467, 6.189 mM), peroxidase (2.328, 3.282, 3.778 mM), superoxide dismutase (2.65, 3.20, 4.89 U g⁻¹), glutathione reductase (2.4568, 4.0234, 5.6712 mM), and ascorbate peroxidase (5.9636, 7.1428, 7.9636 mM) were recorded at pre-, peak-, and post-flowering stages, respectively, at 1000 mg kg⁻¹. However, a further increase to 1250 mg kg⁻¹ resulted in a decline in enzyme activities, indicating the onset of zinc-induced toxicity. The results highlight that moderate zinc enrichment stimulates the plant antioxidant machinery, enhancing tolerance against oxidative stress. Superoxide dismutase plays a pivotal role in dismutating superoxide radicals into H₂O₂, which is subsequently detoxified by catalase, peroxidase, and ascorbate peroxidase, thereby maintaining cellular redox homeostasis. Overall, the study demonstrates a dose-dependent dual role of zinc, acting as both a micronutrient and a potential toxicant at higher concentrations. These findings emphasize the need for careful management of zinc levels in agricultural soils to prevent toxicity while optimizing soybean productivity.
ER  -