关键词: 甘氨酸甜菜碱, 桃果实, 冷害, 抗坏血酸-谷胱甘肽循环

Abstract: The effects of 10 mmol/L glycine betaine dipping treatment on chilling injury and ascorbic acid-glutathione (AsA-GSH) cycle metabolism in peach fruit (Prunus persica Batsch cv. ‘Hujingmilu’) stored at (0 ± 1) ℃ were investigated. The results indicated that glycine betaine treatment could significantly inhibit the incidence of chilling injury in peach fruit and delay the increase in relative electric conductivity, malondialdehyde (MDA) content and hydrogen peroxide content. In addition, glycine betaine treatment could improve the activities of ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase, induce the up-regulation of PpAPX, PpGR, PpMDHAR and PpDHAR gene expression and maintain high levels of ascorbic acid, glutathione, ascorbic acid/dehydroascorbate ratio and glutathione/oxidized glutathione ratio. It is suggested that exogenous glycine betaine can effectively remove excessive hydrogen peroxide in cells and relieve the oxidative damage to the cell membrane caused by low temperature stress by regulating the AsA-GSH cycle, thereby reducing chilling injury symptoms in peach fruit during cold storage.

Key words: glycine betaine, peach fruit, chilling injury, ascorbic acid-glutathione cycle