Table 2_Comparative metabolomics identifies enhanced ursane-type triterpenoids and antioxidant capacity in Actinidia arguta ‘Danyang’ kiwifruit.xlsx

Chemical diversity is crucial for plant ecological adaptation and nutritional value. In kiwifruit, secondary metabolites such as terpenoids influence key traits such as flavor and nutraceutical properties, however, their diversity across different species and cultivars remains poorly characterized. This study employed UPLC-MS/MS-based metabolomics to profile terpenoids in five varieties representing both Actinidia chinensis (cultivars ‘Guichang’, GC; ‘SunGold’, SG; and a wild type, WL) and Actinidia arguta (cultivars ‘Maolvfeng’, LC; ‘Danyang’, DY). We identified 309 terpenoids, revealing profound diversity. Notably, the commercial A. chinensis ‘SunGold’ (SG) and A. arguta ‘Danyang’ (DY) exhibited the highest total terpenoid content, while SG uniquely possessed a soluble sugar content 2.4 to 6 times greater than other varieties. Both varieties also showed the strongest antioxidant capacity (455.20 and 438.91 µg TE/g FW, respectively), suggesting their superior nutraceutical potential. Multivariate analysis confirmed distinct terpenoid fingerprints, with DY enriched in ursane-type triterpenes e.g., pomolic acid, 1-oxo-siaresinolic acid, camellisin B, and siegesbeckic acid, while SG was uniquely abundant in seco-iridoids like geniposide (442-fold higher than WL). Within A. chinensis, the cultivated ‘Guichang’ (GC) showed a significant suppression of most triterpenoids compared to its wild relative (WL), demonstrating a possible breeding or selection effect. Our findings demonstrate that terpenoid profiles are likely influenced by genetic background, both at the species and cultivar level, providing a metabolic roadmap for the targeted breeding of kiwifruit with optimized health, nutraceutical, and sensory properties.

化合物多样性对于植物的生态适应性与营养价值均至关重要。在猕猴桃中，萜类化合物（terpenoids）等次生代谢物会影响风味与保健特性等关键性状，但不同猕猴桃物种与品种间的萜类化合物多样性仍未得到充分解析。本研究采用基于超高效液相色谱-串联质谱（UPLC-MS/MS）的代谢组学方法，对5个代表性猕猴桃品种的萜类化合物进行代谢谱分析，涵盖中华猕猴桃（Actinidia chinensis，品种‘贵长’GC、‘SunGold’SG以及野生型WL）和软枣猕猴桃（Actinidia arguta，品种‘马绿峰’LC、‘丹阳’DY）。本研究共鉴定出309种萜类化合物，展现出极高的代谢多样性。值得注意的是，商业化栽培的中华猕猴桃品种‘SunGold’（SG）与软枣猕猴桃品种‘丹阳’（DY）的总萜类化合物含量最高；其中SG的可溶性糖含量显著高于其余品种，可达其余品种的2.4至6倍。这两个品种同时具备最强的抗氧化能力（分别为455.20和438.91 μg TE/g鲜重），提示其具有更优异的营养保健潜力。多变量分析证实各品种具有独特的萜类化合物指纹图谱：DY富含乌苏烷型三萜类化合物，如坡模酸、1-氧代-西阿树脂酸、山茶素B以及豨莶酸；而SG则特有高丰度的裂环环烯醚萜类化合物，如京尼平苷，其含量较WL高出442倍。在中华猕猴桃类群中，栽培品种‘贵长’（GC）相较于其野生近缘种WL，多数三萜类化合物的含量显著下调，这暗示了育种或选择过程可能产生了相应影响。本研究结果表明，萜类化合物的代谢谱受物种与品种层面的遗传背景共同调控，该发现为培育兼具优良健康功效、保健价值与感官品质的猕猴桃品种提供了代谢层面的指导路线。