龙眼果肉自溶与部分氧化还原酶同工酶变化的关系

Relationship Between Longan Pulp-breakdown and the Changes of Some Oxidoreductase Isozymes

以‘石硖’龙眼果肉为材料,在(4±0.5)℃条件下贮藏,并将贮藏后期不同状态果肉分为自溶与未自溶2部分,对其中的乙醇脱氢酶(ADH)、抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)、细胞色素氧化酶(COD)、苹果酸脱氢酶(MDH)、多酚氧化酶(PPO)、过氧化物酶(POD)、超氧物歧化酶(SOD)8个酶进行同工酶电泳检测,以果肉在贮藏过程中的变化为参照,对龙眼果肉自溶与同工酶变化的关系进行探讨。结果表明:"石硖"龙眼低温贮藏过程中,整果果肉除POD外其余7个酶同工酶酶谱变化不大;但贮藏后期自溶果肉与未自溶果肉酶谱差异显著,其中未自溶果肉与刚采收果肉(第0天)酶谱差异不大。说明即使在同一果实中,自溶与未自溶果肉生理状况明显不同,龙眼采后果肉的生理变化主要集中在自溶果肉部分,未自溶的果肉基本维持与刚采收时相近的生理状态。自溶与未自溶果肉中,APX、CAT、MDH、COD、PPD和POD酶谱条带数目、种类以及表达量间差异显著,这几种酶可能与龙眼果肉的自溶有密切关系。

The isozyme of alcohol dehydrogenase（ADH）,ascorbate peroxidase（APX）,catalase（CAT）,cytochrome c oxidase （COD）,malate dehydrogenase （MDH）,polyphenol oxidase （PPO）,peroxidase （POD） and superoxide dismutase（SOD） in Longan（Dimocarpus longan Lour cv.‘Shixia’）pulp stored at 3-5 ℃ and divided into ‘pulpbreakdown’ and ‘intact’ at the end of storage were determined.The results showed that except the POD isozyme,the other 7 isozymes had a slightly changes in the band during storage of the pulp samples.But the bands of the breakdown pulp hada significant difference from those of the intact pulp which were similar to fresh pulp in 0 day.The results indicated that even in the same fruit pulp,there had a different physiology states between the breakdown pulp and the intact pulp.Postharvest physiology changes toke place mainly in the breakdown pulp of longan.The changes of amount,types and expression of APX,CAT,MDH,COD and POD isozymes＇bands indicated that these enzymes maybe associate closely with pulp-breakdown process of longan pulp.