Metabolomics and Transcriptomics Reveal that Diarylheptanoids Vary in Amomum tsao-ko Fruit Development

Amomum tsao-ko is an important spice and medicinal plant that has received extensive attention in recent years for its high content of bioactive constituents with the potential for food additives and drug development. Diarylheptanoids are major and characteristic compounds in A. tsao-ko; however, the biochemical and molecular foundation of diarylheptanoids in fruit is unknown. We performed comparative metabolomics and transcriptomics studies in the ripening stages of A. tsao-ko fruit. The chemical constituents of fruit vary in different harvest periods, and the diarylheptanoids have a trend to decrease or increase with fruit development. GO enrichment analysis revealed that plant hormone signaling pathways including the ethylene-activated signaling pathway, salicylic acid, jasmonic acid, abscisic acid, and response to hydrogen peroxide were associated with fruit ripening. The biosynthetic pathways including phenylpropanoid, flavonoids, and diarylheptanoids biosynthesis were displayed in high enrichment levels in ripening fruit. The molecular networking and phytochemistry investigation of A. tsao-ko fruit has isolated and identified 10 diarylheptanoids including three new compounds. The candidate genes related to diarylheptanoids were obtained by coexpression network analysis and phylogenetic analysis. Two key genes have been verified to biosynthesize linear diarylheptanoids. This integrative approach provides gene regulation and networking associated with the biosynthesis of characteristic diarylheptanoids, which can be used to improve the quality of A. tsao-ko as food and medicine.草果（Amomum tsao-ko）是一种重要的香料与药用植物，近年来因其富含生物活性成分、具备用作食品添加剂与药物开发的潜力而受到广泛关注。二芳基庚烷类化合物（diarylheptanoids）是草果的主要特征性成分，但目前关于其在果实中的生物化学与分子基础仍不明确。本研究针对草果果实的不同成熟阶段，开展了比较代谢组学与转录组学研究。不同采收期的果实化学成分存在显著差异，二芳基庚烷类化合物的含量随果实发育呈现上升或下降的动态变化趋势。基因本体（Gene Ontology，GO）富集分析显示，乙烯激活信号通路、水杨酸、茉莉酸、脱落酸等植物激素信号通路，以及过氧化氢响应过程，均与果实成熟调控密切相关。苯丙烷类、黄酮类及二芳基庚烷类生物合成通路在成熟果实中呈现高度富集状态。通过对草果果实的分子网络分析与植物化学研究，本研究分离并鉴定了10种二芳基庚烷类化合物，其中包含3种新化合物。通过共表达网络分析与系统发育分析，本研究筛选得到与二芳基庚烷类化合物生物合成相关的候选基因。其中两个关键基因已被验证可介导线性二芳基庚烷类化合物的生物合成。本整合组学研究策略阐明了与特征性二芳基庚烷类化合物生物合成相关的基因调控机制与调控网络，可为提升草果作为食品与药用原料的品质提供理论支撑。