Abstract: Effects of nickel on the growth of wheat seedlings cultivated in solution and the alleviation of nitric oxide (NO)on the nickel toxicity were explored. Treatment of nickel at 100μmol/L caused dramatically reduction in seedling growth, decrease in chlorophyll levels and increase in MDA levels, and the increase in the activities of anti-oxidant enzymes, superoxide dismutase (SOD), guaiacol peroxidase (POD), and glutathione S- transferase (GST) in leaves. However, pretreatment of sodium nitroprusside (SNP), a NO donor , at 400μmol/L for 2 days alleviates significantly the nickel-induced symptom. The levels of chlorophyll and MDA in NO-pretreated seedlings were restored to the levels in the control. It is postulated that NO enhances the capacity of antioxidation in seedlings by increasing the activity of ascorbate peroxidase
(APX) and glutathionein reductase (GR), and the levels of glutathione, and mitigates reduction of contents of calcium and iron induced by nickel.

Key words: Wheat ( Triticum aestivum)