Li Zhongxing, Gao Cai, Fan Tianle, Cui Yilin, Liu Zeyuan, Li Lei, Qian Qian, Cheng Mengjie, Zhan Xiangqiang, Niu Chundong, Ma Fengwang, Yang Peizhi, Guan Qingmei
State Key Laboratory for Crop Stress Resistance and High-Efficiency Production/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi 712100, China.
College of Grassland Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, China.
Hortic Res. 2024 Dec 12;12(3):uhae349. doi: 10.1093/hr/uhae349. eCollection 2025 Mar.
Polyphenols represent a significant class of nutrients in apples, contributing to human health and well-being. Among these, procyanidins stand out as the most prevalent polyphenolic compounds in apple fruits. These compounds are abundant in wild apples and generally low in modern apple cultivars. Therefore, it is crucial to identify and recover genetically lost genes that regulate polyphenol accumulation in order to improve the apple quality. To achieve this, we conducted a genome-wide association study (GWAS) on 15 traits related to polyphenol content, utilizing 134 accessions. We identified 1204 marker-trait associations (MTAs) and 840 candidate genes, including known polyphenol biosynthetic and regulatory genes, such as , , and . Notably, we pinpointed a protein -acyl transferase 10 (PAT10), which is significantly associated with procyanidin content. Through experiments with transgenic calli, we determined that apple () MdPAT10 positively regulated procyanidin accumulation. Furthermore, we identified a 51-bp insertion variant (In-868) on the promoter of the , which influences its expression. Both a yeast one-hybrid (Y1H) assay and an electrophoretic mobility shift assay (EMSA) revealed that MdDof2.4 was able to bind to the promoter of containing In-868 ( ), but not to the promoter of without In-868 ( ). Moreover, MdDof2.4 promoted (with ) expression and increased procyanidin accumulation in fruits. Overall, our results enhance the understanding of the biosynthetic regulation of apple polyphenols and provide a theoretical foundation and genetic resources for breeding apple varieties with optimal polyphenol content.
多酚是苹果中一类重要的营养成分，对人类健康有益。其中，原花青素是苹果果实中最普遍的多酚类化合物。这些化合物在野生苹果中含量丰富，而在现代苹果品种中含量普遍较低。因此，识别和找回调控多酚积累的遗传丢失基因对于提高苹果品质至关重要。为实现这一目标，我们利用134份种质对与多酚含量相关的15个性状进行了全基因组关联研究（GWAS）。我们鉴定出1204个标记-性状关联（MTA）和840个候选基因，包括已知的多酚生物合成和调控基因，如 、 和 。值得注意的是，我们确定了一种蛋白质-酰基转移酶10（PAT10），它与原花青素含量显著相关。通过转基因愈伤组织实验，我们确定苹果（）MdPAT10正向调控原花青素积累。此外，我们在 的启动子上鉴定出一个51bp的插入变异体（In-868），它影响其表达。酵母单杂交（Y1H）试验和电泳迁移率变动分析（EMSA）均表明，MdDof2.4能够结合含有In-868的 的启动子（ ），但不能结合不含In-868的 的启动子（ ）。此外，MdDof2.4促进 （含 ）的表达，并增加果实中原花青素的积累。总体而言，我们的结果加深了对苹果多酚生物合成调控的理解，并为培育具有最佳多酚含量的苹果品种提供了理论基础和遗传资源。
