外源NO对NaCl胁迫下黄瓜幼苗氮化合物和硝酸还原酶活性的影响

Effects of Exogenous NO on NO_3~——N,NH_4^+-N and Soluble Protein Contents and NR Activities in Cucumber Seedlings under NaCl Stress

采用营养液水培的方法,研究了外源一氧化氮(nitric oxide,NO)对50 mmol?L-1NaCl胁迫下黄瓜(Cucu-mis sativusL.)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.

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.