Nitric Oxide Alleviates Oxidative Stress Caused by Lanthanum in Rice Leaves

The effect of NO on lanthanum-induced antioxidant activities in rice was evaluated. The results showed that the uptake and translocation of La from root to shoot were obviously inhibited by 10 μmol · L−1 sodium nitroprusside (SNP), a donor of NO, in the seedlings grown in Mura B nutrient solution with 100 μmol · L−1 La. Although the content of ascorbate acid (AsA) were scarcely affected by La or NO in our experiment, La decreased significantly the activity of SOD and content of GSH, while promoted H2O2 content in leaves. Furthermore, NO blocked these La effects. Taken together, the results suggested that NO relieved La toxicity in rice. A possible role for NO effects on antioxidant activity was discussed.