柑橘果实发育过程中有机酸含量及相关代谢酶活性的变化

 测定了柠檬 (高酸 ,CitruslimonL .Burm)、锦橙 (中酸C .sinesisL .Osbeck)、冰糖橙 (低酸 ,C .sinesisL .Os beck)和奉节脐橙 (C .sinesisL .Osbeck)及其低酸芽变株系、晚熟芽变株系果实在发育过程中柠檬酸的含量及其相关代谢酶活性。结果表明 ,除柠檬外 ,汁胞柠檬酸含量均在花后 10 0～ 130d达到高峰 ,以后逐渐下降 ;柠檬酸合成酶活性变化与各类型柑橘果实中柠檬酸含量差异没有明显联系 ;细胞溶液中的乌头酸酶后期升高对柑橘果实中酸的降解有明显影响 ;磷酸烯醇式丙酮酸羧化酶活性和磷酸烯醇式丙酮酸羧化酶 /NAD 异柠檬酸脱氢酶值较高 ,酸积累较高。

Organic Acid Concentrations and the Relative Enzymatic Changes During the Development of Citrus Fruits

Seasonal changes in enzyme activities and citrate concentration during the development of citrus fruits were investigated. Acid concentration reached a peak in the 100-130 days after anthesis and gradually declined during the later stages of fruit maturation in most varieties of citrus, but declined only slightly thereafter in lemon( Citrus limon (L.) Burm). There is no relation between the activity of CS and different acid concentration in different citrus fruits. The increase of the activity of cytosolic aconitase in the late period of the development of citrus fruits accelerated the degradation of citric acid in citrus fruits. The higher the activity of PEPC and the ratio of PEPC /NAD-IDH, the more the concentrations of organic acids in citrus fruit.