蔗糖含量是决定甜瓜果实品质的关键因素。目前甜瓜果实蔗糖从卸载、转运到在液泡中的积累机制缺乏系统的研究。我们在明确甜瓜果实糖卸载路径为质外体卸载及TST2（液泡糖转运蛋白）和AIN2与甜瓜果实液泡蔗糖积累相关的基础上，拟以高糖和低糖甜瓜品种为材料，转录组测序和qRT-PCR分析筛选与甜瓜果实蔗糖卸载转运密切相关的SWEET和SUT基因。通过原位杂交、免疫组化和亚细胞定位等技术明确基因的组织及亚细胞定位；利用CRISP/cas9基因编辑及甜瓜遗传转化技术来验证关键SWEET和SUT以及TST2和AIN2在甜瓜蔗糖卸载及积累过程中的功能；在明确基因功能的基础上，利用酵母单杂交文库筛选及点对点验证的方法来分析基因的上游调控因子。研究结果将明确关键SWEET、SUT、TST2和AIN22基因一起在甜瓜果实蔗糖从卸载到积累过程中分别扮演的功能及上游调控因子，为甜瓜的优质栽培和育种提供理论基础。

Sucrose content is the key factor that determines the melon fruits’ quality. However, the mechanism of sucrose’s unloading, transport and accumulation in melon fruit has not been systematically studied until now. In our previous study, we found that phloem unloading of mature melon fruit is follow an apoplastic pathway and the function of TST2 (Tonoplast sugar transporter 2) and AIN2 is associated with sucrose accumulation in vacuole of melon fruits. Basing on these results, we will use high and low sugar content melon varieties as materials, using transcriptome sequence and qRT-PCR analysis to screen for key SWEET and SUT genes that involved in sucrose unloading and accumulation in melon fruit. In situ hybridization, immunohistochemistry and subcellular localization were used to determine the tissue and subcellular localization of candidate genes. CRISP/cas9 gene editing and melon genetic transformation technologies were used to verify the functions of candidate SWEET, SUT, TST2 and AIN2 in melon fruit. At last, we will use yeast single hybrid library screening and point-to-point verification to analyze the upstream regulatory factors of the TST2, AIN2 and the key SWEET and SUT. This research will clarify the function and upstream regulators of SWEET, SUT, TST2 and AIN2 during sucrose accumulation in melon fruits. The results will provide a theory basis for high-quality breeding and cultivation of melon.