外源NO对渗透胁迫下黑麦草种子萌发及活性氧代谢的影响

Effects of exogenous nitric oxide on seed germination and reactive oxygen species metabolism of seedling leaves in ryegrass under osmotic stress

以黑麦草为试材,研究了一氧化氮(NO)供体硝普钠(SNP)对聚乙二醇6000渗透胁迫下种子萌发、幼苗叶片活性氧代谢和渗透溶质积累的影响,探讨外源NO对渗透胁迫下牧草生理响应的调节作用。结果表明:100μmol/L SNP显著提高了渗透胁迫下黑麦草种子的发芽率、发芽指数和活力指数,缓解了植株鲜重和干重的下降幅度,提高了幼苗叶片SOD、POD、APX、质膜H+-ATPase活性及谷胱甘肽、可溶性糖、游离氨基酸、脯氨酸、K+、Na+含量和植株含水量,降低了O2.产生速率及H2O2、丙二醛和可溶性蛋白含量。表明外源NO能够促进渗透胁迫下黑麦草种子的萌发,对渗透胁迫引起的黑麦草幼苗膜脂过氧化具有缓解作用。

To discuss the regulating effect of exogenous nitric oxide （NO） on the physiological response of herbage under osmotic stress of simulated by polyethylene glycol, we investigated the effects of exogenous NO donor sodium nitroprusside （SNP） on the seed germination, reactive oxygen species metabolism and osmotica accumulation in seedling leaves with the experimental materials of ryegrass（ Lolium perenne L）. The results showed that under the stress, applying 100/xmol/L SNP increased significantly the seed germination rate, germination index, and vigor index, alleviated the decreases of fresh and dry weights of whole plant, increased the activities of superoxide dismutase （SOD）, guaiacol peroxidase （POD）, ascorbate peroxidase （APX） and plasma membrane H＋ -ATPase and the contents of glutathione, soluble sugar, free amino acid, proline, K＋ , and Na ＋ as well as plant water content, and decreased O2- production rate and the contents of H2O2, malondialdehyde and soluble protein in leaves. The results indicated that exogenous NO could promote the seed germination of ryegrass under osmotic stress and alleviate the membrane lipid peroxidation induced by osmotic stress in seedling leaves.