Ma Jun, Li Guangzong, Chu Yannan, Yue Haiying, Xu Zehua, Wu Jiaqi, Li Xiaolong, Jia Yonghua
Horticultural Research Institute, Ningxia Academy of Agriculture and Forestry, Yinchuan 750002, China.
Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China.
Plants (Basel). 2025 Apr 9;14(8):1165. doi: 10.3390/plants14081165.
We investigated the dynamic changes in volatile aroma compound profiles (types and concentrations) and associated gene expression patterns in both the peel and pulp tissues of apples during fruit maturation. This study aimed to elucidate the metabolic regulatory mechanisms underlying volatile aroma biosynthesis in Malus domestica "Ningqiu" apples, thereby providing theoretical support for the comprehensive utilization of aroma resources. Our methodological framework integrated headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS), ultra-high-performance liquid chromatography-orbitrap mass spectrometry (UHPLC-OE-MS), and Illumina high-throughput sequencing to generate comprehensive metabolomic and transcriptomic profiles of peel and pulp tissues. Critical differential aroma compound classes were identified, including esters, aldehydes, alcohols, terpenoids, and ketones, with their metabolic pathways systematically mapped through KEGG functional annotation. Our findings revealed substantial transcriptomic and metabolomic divergence across carotenoid, terpenoid, and fatty acid metabolic pathways. Integrative analysis of multi-omics data revealed 26 and 31 putative biologically significant hub genes in peel and pulp tissues, respectively, putatively associated with the observed metabolic signatures. Among these, five core genes-farnesyl diphosphate synthase (), alcohol acyltransferases ( and ), alcohol dehydrogenase (), and carotenoid cleavage dioxygenase ()-were recognized as shared regulatory determinants between both tissue types. Furthermore, terpene synthase () emerged as a peel-specific regulatory factor, while hydroperoxide lyase (HPL2), alcohol dehydrogenases ( and ), and alcohol acyltransferase () were identified as pulp-exclusive modulators of metabolic differentiation. The experimental findings provide foundational insights into the molecular basis of aroma profile variation in Malus domestica "Ningqiu" and establish a functional genomics framework for precision breeding initiatives targeting fruit quality optimization through transcriptional regulatory network manipulation.
我们研究了苹果果实成熟过程中果皮和果肉组织中挥发性香气化合物谱（类型和浓度）的动态变化以及相关基因的表达模式。本研究旨在阐明苹果属“宁秋”苹果挥发性香气生物合成的代谢调控机制，从而为香气资源的综合利用提供理论支持。我们的方法框架整合了顶空固相微萃取气相色谱 - 质谱联用（HS-SPME-GC-MS）、超高效液相色谱 - 轨道阱质谱联用（UHPLC-OE-MS）和Illumina高通量测序，以生成果皮和果肉组织的综合代谢组学和转录组学图谱。确定了关键的差异香气化合物类别，包括酯类、醛类、醇类、萜类和酮类，并通过KEGG功能注释系统地绘制了它们的代谢途径。我们的研究结果揭示了类胡萝卜素、萜类和脂肪酸代谢途径在转录组学和代谢组学上的显著差异。多组学数据的综合分析分别在果皮和果肉组织中发现了26个和31个假定具有生物学意义的确切核心基因，这些基因可能与观察到的代谢特征相关。其中，五个核心基因——法呢基二磷酸合酶（）、醇酰基转移酶（和）、乙醇脱氢酶（）和类胡萝卜素裂解双加氧酶（）——被认为是两种组织类型之间共同的调控决定因素。此外，萜烯合酶（）成为果皮特异性调控因子，而过氧化物裂解酶（HPL2）、乙醇脱氢酶（和）以及醇酰基转移酶（）被确定为果肉特有的代谢分化调节因子。实验结果为苹果属“宁秋”香气特征变化的分子基础提供了基础性见解，并建立了一个功能基因组学框架，用于通过转录调控网络操纵来优化果实品质的精准育种计划。
