| In order to explore the influences of oxidative damage by nitric oxide (NO) on maize seedlings under drought stress, a pot experiment to investigate the effects of exogenous nitric oxide donors (sodium nitroprusside, SNP) at concentrations of 0.01, 0.05, 0.1, 0.5 mmol·L-1 and 1.0 mmol·L-1 on membrane lipid peroxidation was carried out using Zhengdan 958 as experimental material. The results showed that appropriate concentration (0.05 mmol·L-1) of exogenous NO could relieve the damage from drought stress, significantly improving the activity of protective enzymes SOD and CAT. Compared with those under drought stress, the SOD and CAT activities were increased by 23.89% and 87.78%, respectively. Proline, soluble sugar, soluble protein and chlorophyll content were increased by 23.89%, 87.78%, 43.44%, 39.84%, 41.33% and 21.45%, respectively. However, MDA content and membrane permeability were significantly reduced by 11.76% and 51.17%, respectively. There were dosage effects of exogenous nitric oxide donor (SNP) on alleviation of drought stress in maize seedlings, which significantly enhanced the drought tolerance of maize seedlings. |