Temperature control is an effective method to maintain the postharvest quality of fruit and extend their shelf life. However, quality deterioration, or more specifically, faded sweetness, occurs in long-term cold-stored melons. This study aimed to characterize the transcriptomic profiles of Gold Queen Hami melon using RNA sequencing at different storage temperatures (21 °C, 3 °C, and 0.5 °C). The results indicated that storage temperature significantly affected the expression of numerous genes in the melon fruit, especially several key genes involved in the starch and sucrose metabolism pathway. The findings revealed that 23 genes presented opposite expression pattern between 3 °C and 21 °C, and 62 chilling-related candidate genes were obtained. Sweetness loss in Hami melons was enhanced at storage temperatures of 3 °C and 0.5 °C. Furthermore, storage at 3 °C was found to decelerate Hami melon softening, as the degradation of pectin and expression of polygalacturonase (PG) were reduced. Moreover, storage at 0.5 °C promoted starch degradation by regulating the expression of α-amylase (AMY) and β-amylase (BMY) genes, subsequently, the levels of soluble sugars increased, potentially preventing physiological or cellular damage from cold stress in the melon fruit. These results indicated that softening was delayed at 3 °C, but the sweetness of the Hami melon was negatively affected at the level of gene transcription, explaining the faded sweetness of cold-stored melon fruit.

温度控制是保持水果采后质量并延长其保质期的有效方法。但是，长期冷藏的甜瓜会出现质量下降，或更具体地说，甜味减弱。这项研究旨在通过在不同存储温度（21°C，3°C和0.5°C）下使用RNA测序来表征哈密瓜皇后瓜的转录组谱。结果表明，贮藏温度显着影响瓜果中许多基因的表达，特别是淀粉和蔗糖代谢途径中涉及的几个关键基因。这些发现揭示了在3℃至21℃之间有23种表达相反的基因，获得了62种与冷害相关的候选基因。在3°C和0.5°C的储存温度下，哈密瓜的甜味损失增加。此外，由于果胶的降解和聚半乳糖醛酸酶（PG）的表达减少，发现在3°C下储存会降低哈密瓜的软化速度。此外，在0.5°C下储存可通过调节α-淀粉酶（AMY）和β-淀粉酶（BMY）基因的表达来促进淀粉降解，随后可溶性糖的含量增加，从而有可能防止冷胁迫下生理或细胞损伤。瓜果。这些结果表明，在3°C时软化被延迟了，但是哈密瓜的甜度在基因转录水平上受到了负面影响，这说明了冷藏瓜果的甜度逐渐降低。5°C通过调节α-淀粉酶（AMY）和β-淀粉酶（BMY）基因的表达来促进淀粉降解，随后可溶性糖水平增加，有可能防止甜瓜果实因冷胁迫而遭受生理或细胞损伤。这些结果表明，在3°C时软化被延迟了，但是哈密瓜的甜度在基因转录水平上受到了负面影响，这说明了冷藏瓜果的甜度逐渐降低。5°C通过调节α-淀粉酶（AMY）和β-淀粉酶（BMY）基因的表达来促进淀粉降解，随后可溶性糖水平增加，有可能防止甜瓜果实因冷胁迫而遭受生理或细胞损伤。这些结果表明，在3°C时软化被延迟了，但是哈密瓜的甜度在基因转录水平上受到了负面影响，这说明了冷藏瓜果的甜度逐渐降低。