文献类型： 外文期刊

作者： Tang, Mi ¹ ; Bie, Zhi-long ¹ ; Wu, Ming-zhu ² ; Yi, Hong-ping ² ; Feng, Jong-xin ² ;

作者机构： 1.Huazhong Agr Univ, Coll Hort & Forestry, Key Lab Hort Plant Biol, Minist Educ, Wuhan 430070, Peoples R China

2.Xinjiang Acad Agr Sci, Res Ctr Hami Melon, Urumqi 830000, Peoples R China

关键词： Citric acid;Aconitase;Malic enzyme;Phosphoenolpyruvate carboxylase;Citrate synthase;Isocitrate dehydrogenase

期刊名称：SCIENTIA HORTICULTURAE （ 影响因子：3.463； 五年影响因子：3.672 ）

ISSN： 0304-4238

年卷期： 2010 年 123 卷 3 期

页码：

收录情况： SCI

摘要： A novel melon cultivar ('Flavor No. T) containing high acid concentration as well as high sugar content in the mature fruit was successfully bred out. The aim of this study is to determine the main organic acids present in this novel melon and to clarify the mechanisms of acid accumulation. Fruit development and acid accumulation patterns in 'Flavor No.3' were compared with those of a conventional low-acid melon, 'Xuelihong'. The titratable acidity (TA) and organic acids in fruits were measured at different developmental stages. There is a positive correlation between TA and citric acid content in 'Flavor No. T, indicating that citric acid is the predominant organic acid present throughout the fruit development. The activities of the enzymes involved in citric acid metabolism, including phosphoenolpyruvate carboxylase (PEPC), citrate synthase (CS), aconitase (ACO), isocitrate dehydrogenase (IDH), malate dehydrogenase (MDH), and malic enzyme (ME), were determined. Although no single enzyme was responsible for citric acid accumulation throughout the fruit development, the activities of ACO and ME were positively correlated with citric acid concentration in the two cultivars from 5 to 25 days after pollination (DAP). Moreover, ACO and ME activities in 'Flavor No. 3' increased over time and were higher than those in 'Xuelihong', resulting in citric acid accumulation in the fruits of 'Flavor No. 3'. Although a sharp decrease in ACO activity took place after 25 DAP in the fruits of 'Flavor No. T, the earlier accumulation of citric acid was sufficient enough to maintain the high acid concentration until the melon fruits became mature. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.