Table_3_Analysis of Metabolites and Gene Expression Changes Relative to Apricot (Prunus armeniaca L.) Fruit Quality During Development and Ripening.xlsx

Apricot (Prunus armeniaca L.) is a valuable worldwide agronomical crop, with a delicious fruit highlighted as a functional food with both nutritional and bioactive properties, remarkably beneficial to human health. Apricot fruit ripening is a coordinated developmental process which requires change in the expression of hundreds to thousands of genes to modify many biochemical and physiological processes arising from quality characteristics in ripe fruit. In addition, enhancing fruit and nutraceutical quality is one of the central objectives to be improved in the new varieties developed by breeding programs. In this study we analyzed the contents of main metabolites linked to the nutraceutical value of apricot fruits, together with the most important pomological characteristics and biochemical contents of fruit during the ripening process in two contrasted apricot genotypes. Additionally, the gene expression changes were analyzed using RNA-Seq and real time qPCR. Results showed that genes with differential expression in the biosynthetic pathways, such as phenylpropanoids, flavonoids, starch and sucrose and carotenoid metabolism, could be possible candidates as molecular markers of fruit quality characteristics for fruit color and soluble solid content. The gene involves in carotenoid metabolism carotenoid cleavage dioxygenase 4, and the gene sucrose synthase in starch and sucrose metabolism were identified as candidate genes in the ripening process for white skin ground color and flesh color and high soluble sugar content. The application of these candidate genes on marker-assisted selection in apricot breeding programs may contribute to the early selection of high-quality fruit genotypes with suitable nutraceutical values.

杏（Prunus armeniaca L.）是全球极具经济价值的农艺作物，其果实风味鲜美，作为兼具营养与生物活性的功能食品广受认可，对人体健康具有显著益处。杏果实成熟是一个协同调控的发育过程，需要数百乃至数千个基因的表达发生改变，以调控成熟果实品质特征所关联的诸多生化与生理进程。此外，提升果实品质与营养保健价值，是育种项目培育新品种的核心目标之一。本研究针对两种性状差异显著的杏基因型，分析了其果实成熟过程中与保健价值相关的主要代谢物含量，以及核心的果实园艺学特征与生化成分。同时，本研究通过RNA测序（RNA-Seq）与实时定量聚合酶链式反应（real-time qPCR）分析了基因表达的变化情况。研究结果显示，苯丙烷类、黄酮类、淀粉与蔗糖以及类胡萝卜素代谢等生物合成通路中的差异表达基因，可作为果实品质特征（如果实色泽与可溶性固形物含量）的分子标记候选基因。其中，参与类胡萝卜素代谢的类胡萝卜素裂解双加氧酶4（carotenoid cleavage dioxygenase 4），以及参与淀粉与蔗糖代谢的蔗糖合酶（sucrose synthase），被鉴定为与果实成熟过程中白色果皮底色、果肉色泽及高可溶性糖含量相关的候选基因。将这些候选基因应用于杏育种的标记辅助选择（marker-assisted selection），将有助于早期筛选出具备优良保健价值的高品质果实基因型。