中文摘要：

采用营养液水培的方法，研究了外源一氧化氮（nitric oxide，NO）对50mmol·L^-1 NaCl胁迫下黄瓜（Curumissativus L．）幼苗根系和叶片内硝酸还原酶（nitrate reductase，NR）活性、硝态氮（NO3^--N）、铵态氮（NH4^＋-N）及可溶性蛋白含量的影响。结果表明：100μmol·L^-1外源NO供体硝普钠（sodium nitroprusside，SNP）能明显提高NaCl胁迫下黄瓜幼苗叶片和根系内NR的活性。缓解由于盐胁迫造成的NO3^--N含量的下降，减少NH4^＋-N在植株体内的过量积累，提高渗透调节物质可溶性蛋白的含量，从而减轻由于盐胁迫对黄瓜幼苗植株造成的伤害。

英文摘要：

Nutrient solution hydroponics was adopted to NH4^＋-N and soluble protein contents and NR activities study the effects of exogenous NO on NO3^--N , in the roots and leaves of cucumber seedlings suffering the stress created with NaCl at 50 mmol·L^-1. It was shown that with its concentration at 100μmol·L^-1 exogenous sodium nitroprusside, the NO donor, could raise the NR activities remarkably, slowed down the NO3^--N decrease resulting from the salt stress and reduced the excessive NH4^＋-N accumulation and increased the content of soluble proteins, osmosis-regulating substances, in the root and leaves of cucumber seedlings suffering the NaCl stress, thereby abating the injury of salt stress to seedling plants of cucumber.