Abstract: Exogenous application of 10 μmol/L sodium nitroprusside (SNP), a nitric oxide (NO) donor, obviously counteracted the accumulation of malondialdehyde (MDA), a lipid peroxidation product in roots of rice seedling under salt stress, and significantly increased soluble protein content in roots of rice seedling. Meanwhile, the activities of ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD) were induced in roots of rice seedling by 10 μmol/L SNP treatment under salt stress. However, the opposite effects of higher concentration of 50 μmol/L SNP were found. All these above indicated that exogenous lower concentration of NO could effectively attenuate the oxidative damage caused by salt stress, which was mainly achieved by means of enhancing anti-oxidative capability in roots of rice seedling.

Key words: nitric oxide, salt stress, rice seedling, root, oxidative damage, antioxidation

摘要： 在100 mmol/L NaCl的胁迫条件下，研究了两种浓度的一氧化氮供体硝普钠（sodium nitroprusside，SNP）处理对水稻幼苗根部脂质过氧化的影响。低浓度（10 μmol/L）的SNP处理明显缓解盐胁迫下水稻幼苗根组织膜脂过氧化产物MDA的累积，显著提高可溶性蛋白含量，并诱导根系APX、POD和SOD活性的上升；而高浓度（50 μmol/L）SNP处理的效果则基本相反。表明外源低浓度NO可以通过提高盐胁迫下水稻幼苗根组织的抗氧化能力来缓解氧化损伤。

关键词: 一氧化氮, 盐胁迫, 水稻幼苗, 根系, 氧化损伤