琯溪蜜柚汁胞在发育与粒化过程中APX活性变化及其同工酶分析

Activity and Isozyme of Ascorbate Peroxidase in Pomelo (Citrus grandis ‘Guanximiyou’) during Juice Sac Development and Granulation

摘要:

对不同发育时期的琯溪蜜柚(Citrus grandis ‘Guanximiyou’)汁胞进行APX活性测定及同工酶分析。结果表明，随着汁胞的发育，APX活性增大；而柚子衰老腐烂时，APX活性迅速降低。APX同工酶随着汁胞发育而发生变化，花后150 d的APX同工酶增加了1个组分(迁移率0.66), 且随着汁胞的成熟, 其表达量增加。花后230 d时柚子开始衰老腐烂，花后242 d已难以看到大部分APX同工酶酶谱。粒化汁胞的APX活性比正常汁胞大，同工酶酶谱亮度和清晰度也大, 推测琯溪蜜柚汁胞在粒化过程中APX可清除活性氧自由基，抵抗氧化损伤。

Abstract:

The changes in activity and isozyme of ascorbate peroxidase (APX) in pomelo (Citrus grandis ‘Guanximiyou’) juicy sac were studied at different development stages. The results showed that APX activity increased gradually with juicy sac development and decreased rapidly at aging and rotting stages. The APX isozyme also changed during juicy sac development stages. A new APX isozyme was identified with mobility of 0.66 on 150 days after anthesis, and its expression enhanced with maturity of juicy sac. On 242 days after anthesis, most of APX isozyme disappeared. The APX activity in normal juicy sac was lower than that in granulated juicy sac. It suggested that APX could scavenge active oxygen free radicals and prevent the oxidative damage during pumelo juicy sac granulation stage.