Seed aging is a problem during long-term seed storage, affecting the commercial and germplasm value of seeds. In this study, a widely cultivated rice ( Oryza sativa L.) cultivar, Huanghuazhan, was used to investigate the effects of exogenous spermidine (Spd) on accelerated aging (AA). The results showed that the speed of germination and the activities of catalase (CAT), ascorbate peroxidase (APX) and β-amylase were reduced by AA, and more H 2 O 2 accumulated in aged seeds than in normal seeds. As compared with aged seeds pretreated with water, seed vigor and the gibberellic acid (GA) content in aged seeds pretreated with Spd were increased by 47% and 17%, respectively. Furthermore, antioxidant enzyme activity and related gene expression were also higher in aged seeds pretreated with Spd. It is speculated that CAT and APX are the two primary enzymes involved in the effects of Spd to AA. These results suggest that the adverse effect of AA stress on seeds may be partially alleviated by the application of exogenous Spd, which may affect the scavenging of reactive oxygen species.

中文翻译：

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亚精胺增强水稻种子老化过程中的抗氧化能力

种子老化是种子长期储存过程中的一个问题，影响种子的商业价值和种质价值。在这项研究中，使用广泛栽培的水稻（ Oryza sativa L. ）品种黄花占研究外源亚精胺（Spd）对加速衰老（AA）的影响。结果表明，AA降低了发芽速度和过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）和β-淀粉酶的活性，老化种子中积累的H 2 O 2 比正常种子多。与水预处理的老化种子相比，Spd预处理的老化种子的种子活力和赤霉酸(GA)含量分别增加了47%和17%。此外，用 Spd 预处理的老化种子的抗氧化酶活性和相关基因表达也更高。据推测，CAT 和 APX 是参与 Spd 对 AA 影响的两种主要酶。这些结果表明 AA 胁迫对种子的不利影响可以通过外源 Spd 的应用得到部分缓解，这可能会影响活性氧的清除。