Abstract Loss of organic acids during postharvest storage is one of the major factors that negatively affect the quality and storage performance of citrus fruit. ‘Qianyang Bingtang’ navel orange (QY-BTNO) and ‘Jinxiu Bingtang’ sweet orange (JX-BTO) are bud mutants of common ‘Bingtang’ sweet orange (CK-BTO) (Citrus sinensis Osbeck), and are respectively characterized by the trait of higher and lower accumulations of organic acids in fruit juice sacs, which is maintained throughout the storage period. Here, gene expression analysis on citrate metabolism showed that the high citrate accumulation in QY-BTNO could be attributed to the high expression of the p-type proton pump gene (PH8), and might be partially due to the low activity of citrate degradation pathway as indicated by the low expression of aconitase (ACO) and glutamate dehydrogenase (GAD). QY-BTNO had significantly lower fruit disease incidence than JX-BTO. Besides, the content of energy source ATP and the activity of peroxidase (POD) were observably different between QY-BTNO and JX-BTO.

中文翻译：

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CsPH8参与柠檬酸积累与'冰糖'甜橙突变体果实贮藏性能直接相关

摘要 采后贮藏过程中有机酸的流失是影响柑橘果实品质和贮藏性能的主要因素之一。'钱阳冰糖'脐橙（QY-BTNO）和'金秀冰糖'甜橙（JX-BTO）是普通'冰糖'甜橙（CK-BTO）（Citrus sinensis Osbeck）的芽突变体，分别具有以下特点：果汁囊中有机酸积累较高和较低的特征，在整个储存期间保持不变。在这里，柠檬酸代谢的基因表达分析表明，QY-BTNO 中柠檬酸的高积累可能归因于 p 型质子泵基因 (PH8) 的高表达，部分原因可能是柠檬酸降解途径的低活性如乌头酸酶 (ACO) 和谷氨酸脱氢酶 (GAD) 的低表达所示。QY-BTNO果实病害发生率显着低于JX-BTO。此外，QY-BTNO和JX-BTO的能量源ATP含量和过氧化物酶（POD）活性存在明显差异。