Key Laboratory of Plant Resources, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China.
Food Chem. 2013 Dec 15;141(4):3323-8. doi: 10.1016/j.foodchem.2013.06.025. Epub 2013 Jun 14.
Sugars are essential contributors to fruit flavour. Controlled atmosphere (CA) storage has been proved to be beneficial for maintaining harvested fruit quality. To explore regulatory mechanism of sugar metabolism in fruit stored in CA condition, we cloned several genes, encoding key enzymes, involved in sugar metabolism in apple fruit, and analyzed sugar contents, along with gene expression and enzyme activities in fruits stored in air and CA. The results indicated that CA could maintain higher contents of sugars, including sucrose, fructose and glucose. Expression levels of key genes, such as sucrose synthase (SS), sucrose phosphate synthase (SPS), fructokinase (FK) and hexokinase (HK), were shown to be correlated with the corresponding enzyme activities. We found that activities of neutral invertase (NI), vacuolar invertase (VI), FK and HK were inhibited, but SPS activity was promoted in apple fruit stored in CA, suggesting that CA storage could enhance sucrose synthesis and delay hydrolysis of sucrose and hexose. These findings provided molecular evidence to explain why higher sugar levels in harvested fruit are maintained under CA storage.
糖是水果风味的重要组成部分。控制气氛（CA）贮藏已被证明有利于保持收获后水果的品质。为了探索 CA 贮藏条件下果实糖代谢的调控机制，我们克隆了几个参与苹果果实糖代谢的关键酶的基因，并分析了果实中糖的含量，以及在空气和 CA 中贮藏的果实的基因表达和酶活性。结果表明，CA 可以维持更高的糖含量，包括蔗糖、果糖和葡萄糖。关键基因如蔗糖合酶（SS）、蔗糖磷酸合酶（SPS）、果糖激酶（FK）和己糖激酶（HK）的表达水平与相应的酶活性相关。我们发现，中性转化酶（NI）、液泡转化酶（VI）、FK 和 HK 的活性受到抑制，但 CA 贮藏的苹果果实中 SPS 的活性增强，这表明 CA 贮藏可以促进蔗糖的合成，延缓蔗糖和己糖的水解。这些发现为解释为什么在 CA 贮藏下收获果实中的糖含量更高提供了分子证据。
