Sweetness is one of the key factors determining peach fruit quality. To better understand the molecular basis of gibberellic acid (GA) and 1-naphthaleneacetic acid (NAA) interference with sugar biosynthesis, a middle-late maturing commercial cultivar, ‘Jinxiu’ yellow peach fruit, was treated with three different concentrations of GA4+7 and four of NAA. Fruit weight, firmness, total soluble solids, different sugar contents and the expression level of sugar-related genes were evaluated. The results showed that maximum increase in cv. ‘Jinxiu’ peach fruit size and sucrose content was with 1.25 mM GA4+7, compared to control fruits and the other treatments during the ripening stages. The sucrose-phosphate synthase gene (PpSPS2) which had a high level of expression and positive correlation with sucrose content was significantly regulated by 1.25 mM GA4+7 in the final ripening stages. 0.5 mM NAA treatments significantly reduced the sucrose content and fruit size. Ninety percent of the fruits were deformed or dropped from the trees with treatments of 1 mM NAA and 2 mM NAA in the early development period. The crosstalk of different phytohormones and the related genes will be further investigated to get an insight into the inherent association between hormone control and sugar accumulation.

中文翻译：

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外源施用GA4+7和NAA对桃果实发育和成熟期糖积累及相关基因表达的影响

甜度是决定桃果实品质的关键因素之一。为了更好地了解赤霉酸 (GA) 和 1-萘乙酸 (NAA) 干扰糖生物合成的分子基础，用三种不同浓度的 GA4+7 处理中晚熟商业品种“金秀”黄桃果实和四个 NAA。评价果实重量、硬度、总可溶性固形物、不同糖含量和糖相关基因的表达水平。结果表明，cv的最大增加。与成熟阶段的对照果实和其他处理相比，'锦绣'桃果实大小和蔗糖含量为 1.25 mM GA4+7。高表达且与蔗糖含量呈正相关的蔗糖磷酸合酶基因(PpSPS2)受1的显着调控。25 mM GA4+7 在最后成熟阶段。0.5 mM NAA 处理显着降低了蔗糖含量和果实大小。90% 的果实在发育早期用 1 mM NAA 和 2 mM NAA 处理从树上变形或掉落。将进一步研究不同植物激素和相关基因的串扰，以深入了解激素控制与糖积累之间的内在关联。