外源一氧化氮对盐胁迫下烟草幼苗生理及抗氧化性的影响

Effects of Exogenous Nitric Oxide on Physiology and Antioxidant Activity of Tobacco Seedlings under Salt Stress

为探究外源一氧化氮(NO)对盐胁迫下烟草幼苗的影响,为了解烟草抗盐机制和生产应用提供一定参考,以烟草品种K326为研究对象,使用硝普钠(sodium nitroprusside,SNP)作为外源一氧化氮供体,研究不同处理烟草幼苗的生理及抗氧化性。试验结果表明,盐胁迫会显著抑制幼苗的正常生长发育,通过使用不同浓度的SNP预处理后,烟草幼苗叶片含水率明显上升,根系活力上升,提高了胁迫环境下的叶绿素含量,渗透物质含量显著增加,幼苗体内的多种抗氧化酶含量显著升高,过氧化氢含量和MDA含量下降,降低了膜脂过氧化的程度,保护细胞结构不被破坏,降低叶片细胞透性。试验结果说明,外源一氧化氮可以有效提高烟草幼苗的耐盐性,并且具有明显的浓度效应,0.10mmol/L SNP预处理的效果最好,试验结果为提高烟草的耐盐性提供一定依据。

In order to explore the effect of exogenous nitric oxide（NO） on tobacco seedlings under salt stress and provide some references to understand the mechanism of salt resistance in tobacco production, tobacco variety K326 was used as research object and sodium nitroprusside（SNP） exogenous nitric oxide donor was used to study the physiological and antioxidant activities of tobacco seedlings under different treatments. The results showed that salt stress could significantly inhibit the normal growth and development of seedlings. After pretreatment with different concentrations of SNP, the leaf water content of tobacco seedlings increased significantly and the root activity increased, which increased the chlorophyll content and osmotic substance content. The antioxidant enzyme content in seedlings significantly increased, but hydrogen peroxide content and MDA content decreased, reducing the degree of membrane lipid peroxidation, protecting the cell structure against destroying, reducing leaf cell permeability. The results showed that exogenous nitric oxide could effectively improve the salt tolerance of tobacco seedlings, and had a significant concentration effect. Pretreatment using 0.10 mmol/L SNP was the best for improving the salt tolerance of tobacco.