Sucrose accumulation is one of the important factors that determine fruit enlargement and quality. Evaluation of the sugar profile of 105 pear cultivars revealed low-sucrose and high-sucrose (HS) types of pear fruits. To better understand the molecular mechanisms governing the sucrose content of pear fruits, this study performed transcriptome analysis during fruit development using low-sucrose ‘Korla’ fragrant pear and HS ‘Hosui’ pear, and a coexpression module uniquely associated with the control of high-sucrose accumulation was identified by weighted gene coexpression network analysis. These results suggested that there are seven candidate genes encoding key enzymes (fructokinase, glucose-6-phosphate isomerase, sucrose phosphate synthase and sucrose synthase) involved in sucrose biosynthesis and several transcription factors (TFs) whose expression patterns correlate with those of genes associated with sucrose biosynthesis. This correlation was confirmed by linear regression analysis between predicted gene expression and sucrose content in different pear cultivars during fruit development. This study provides insight into the molecular mechanism underlying differences in sucrose content across pear cultivars and presents candidate structural genes and TFs that could play important roles in regulating carbohydrate partitioning and sucrose accumulation.

中文翻译：

---

低和高蔗糖梨品种的转录组分析确定了水果中蔗糖生物合成的关键调控因子。

蔗糖的积累是决定果实膨大和品质的重要因素之一。对105个梨品种的糖谱进行评估后发现，低果糖和高蔗糖（HS）类型的梨果实。为了更好地了解控制梨果实中蔗糖含量的分子机制，本研究在果实发育过程中使用了低蔗糖'Korla'香梨和HS'Hosui'梨，以及一个与高糖控制有关的共表达模块，进行了转录组分析。通过加权基因共表达网络分析鉴定蔗糖积累。这些结果表明，存在七个编码关键酶的候选基因（果糖激酶，6-磷酸葡萄糖异构酶，蔗糖磷酸合成酶和蔗糖合成酶）与蔗糖生物合成有关，还有一些转录因子（TFs）的表达方式与与蔗糖生物合成相关的基因相关。通过对果实发育过程中不同梨品种的预测基因表达与蔗糖含量之间的线性回归分析，证实了这种相关性。这项研究提供了深入了解梨品种中蔗糖含量差异的分子机制，并提出了可能在调节碳水化合物分配和蔗糖积累中发挥重要作用的候选结构基因和TF。通过对果实发育过程中不同梨品种的预测基因表达与蔗糖含量之间的线性回归分析，证实了这种相关性。这项研究提供了深入了解梨品种中蔗糖含量差异的分子机制，并提出了可能在调节碳水化合物分配和蔗糖积累中发挥重要作用的候选结构基因和TF。通过对果实发育过程中不同梨品种的预测基因表达与蔗糖含量之间的线性回归分析，证实了这种相关性。这项研究提供了深入了解梨品种中蔗糖含量差异的分子机制，并提出了可能在调节碳水化合物分配和蔗糖积累中发挥重要作用的候选结构基因和TF。