摘要： 为了探讨渗透调节在盐渍环境下减轻或避免胁迫损伤中的作用,以抗性玉米品种农大108为材料,研究了在不同比例海水处理过程中NO供体硝普钠(Sodium nitroprusside,SNP)对玉米幼苗根系渗透调节相关指标的影响.结果表明:随着海水浓度的增加,幼苗根系中的游离脯氨酸含量、相对电导率和相对含水量明显升高,丙二醛含量增加,而可溶性糖含量下降;当海水浓度不高于2%时,随着SNP浓度的增加,脯氨酸、相对电导率、丙二醛和相对含水量升高,而可溶性糖含量降低;当海水浓度超过2%时,高浓度SNP处理使脯氨酸、可溶性糖和相对含水量明显减少,相对电导率下降,而丙二醛含量显著增加.说明一氧化氮对根系的渗透调节与胁迫程度有关,一般较高浓度的一氧化氮能显著缓解轻度海水胁迫,而较低浓度的一氧化氮有利于减轻严重海水胁迫.

关键词: 一氧化氮, 海水胁迫, 玉米根系, 渗透调节

Abstract: In order to determine the effects of osmotic adjustment in alleviating or eliminating saline stress damage,the changes of some osmosis-related indexes in the roots of seedlings of stress-tolerant maize variety Nongda108 were studied after the treatments of mixed seawater with freshwater by the different ratio combined with nitric oxide donor,sodium nitroprusside(SNP) . The results indicate: following seawater rate increases,the contents of free proline, relative water and methyldialdehyde and relative electroconductance rise respectively,but the contents of soluble sugar decline in the roots of seedlings. When the seawater content is not above twenty-five percent,and as well as,the SNP concentration rise,the contents of proline,methyldialdehyde and relative water and relative electroconductance increase respectively,but the contents of soluble sugar decrease. When the seawater content is more than twenty-five percent,exogenously applying the SNP with high concentration obviously decreases the contents of proline,soluble sugar and relative water,and reduces relative electroconductance,whereas notably enhancing contents of methyldialdehyde. This means the osmotic function of nitric oxide on roots is related to the stress degree in the surroundings. In general,higher concentration of nitric oxide may evidently mitigates the slight seawater stress,but lower concentration of nitric oxide help alleviating severe seawater stress.

Key words: Nitric oxide, Seawater stresses, Roots of maize seedlings, Osmotic adjustment

中图分类号: 

• S13.01