草酸对冷藏期间桃果实抗氧化系统和PPO活性的影响

Changes in Antioxidant Systems and Polyphenol Oxidase Activity in Peach Fruit Treated with Exogenous Oxalic Acid during Storage at Low Temperature

桃(Prunus persicaL.)栽培品种‘八月脆’果实采后经5mmol·L-1草酸溶液浸泡10min后在低温条件下贮藏,与对照相比,果实的CAT和PPO活性提高,SOD和POD活性在贮藏10d后较高;还原型抗坏血酸(AsA)含量下降减缓;超氧阴离子(O·2)生成速率随贮藏增加,过氧化氢(H2O2)含量先升后降,但经草酸处理后O·2生成速率和H2O2含量分别在5d和5、10d时显著低于对照。说明草酸处理通过提高果实抗氧化防御系统的能力和PPO活性来延缓果实成熟和增强果实抗病能力。

Peach （Prunus persica L.‘ Bayue Cui＇ ） fruit were dipped in a 5 mmol · L^-1 oxalic acid solution for 10 min and then stored at low temperature for 20 days. Changes in antioxidant ability and polyphenol oxidase （POD） activity in the fruit were investigated during storage. The results showed that, as compared with control fruit, higher activities of superoxide dismutase （SOD）, peroxidaes （POD）, catalase （CAT） and PPO were observed and lose of ascorbate acid （AsA） was delayed. Moreover, to some extent, active oxygen species （AOS） production including superoxide （O2^-） and hydrogen peroxide （H2O2 ） was inhibited in treated fruit. It was suggested that effects of oxalic acid on increases of antioxidant ability and PPO activity might be beneficial in delaying ripening process and enhancement of disease resistance in peach fruit during storage at low temperature.