一氧化氮对家榆种子老化的影响及其作用机制研究

Preliminary Research on the Role and Mechanism of Nitric Oxide during Elm Seeds Ageing

以家榆种子为试材,采用种子活力检测技术、激光共聚焦显微镜技术、蛋白质S-亚硝基化检测技术,结合多种相关抑制剂的使用,研究了NO对种子老化的影响及其作用机制。结果表明:(1)外源NO可显著提升老化处理后种子的活力,NO清除剂cPTIO可降低老化处理后种子的活力,且此影响可被NO供体硝普钠所恢复。(2)硝酸还原酶底物亚硝酸钠、类一氧化氮合酶底物L-精氨酸(L-Arg)均可提高老化处理后种子的活力,2种酶的抑制剂可降低种子活力,且此影响可被NO供体硝普钠所恢复,即硝酸还原酶与类一氧化氮合酶可参与种子老化过程中NO的产生。(3)种子老化过程中NO首先在子叶中合成,随后在胚根尖部、生长点与下胚轴等部位出现,蛋白质S-亚硝基化水平与NO在种子中产生的时间特点一致。研究认为,NO可提高种子抗老化能力,种子内NO可通过硝酸还原酶途径和类一氧化氮合酶途径产生,且与种子蛋白质S-亚硝基化水平相关。

In this study, taking etm（Ulmus pumila L. ） seeds as materials,we combined the use of seed vigor detection technology,confocal laser scanning microscopy, protein S-nitrosylation detection technology and pharmacology of many nitric oxide inhibitors, to investigate the role and the mechanism of nitric oxide dur- ing seed ageing. The results showed that. （1）Nitric oxide donor SNP can improve seed vigor after ageing. The scavenger of nitric oxide cPTIO can suppress the seed vigor after ageing,and the suppressions can be recovered by nitric oxide donor SNP. These illustrated that nitric oxide can improve the ability of anti-age- ing. （2）The substrates of nitrite reductase and nitric oxide synthase like enzyme can improve seed vigor af- ter ageing. The inhihitors of nitrite reduetase and nitric oxide synthase like enzyme can suppress the seed vigor after ageing,and the suppressions can be recovered by nitric oxide donor SNP. These illustrated that nitric oxide can be produced by nitrite reductase pathway and nitric oxide synthase like enzyme pathway. （3）Nitric oxide was first produced in cotyledon,then in radical,shoot apex and hypocotyl. The level of pro- tein S-nitrosylation was in accordance with temporal characteristics of nitric oxide produce. In conclusion, nitric oxide can improve the ability of anti-ageing,and can be produced by nitrite reductase pathway and nitric oxide synthase like enzyme pathway. The level of S-nitrosylation was also related to nitric oxide production.