Table_11_Integrated volatile metabolomic and transcriptomic analysis provides insights into the regulation of floral scents between two contrasting varieties of Lonicera japonica.XLSX

Lonicera japonica Thunb., belonging to the Caprifoliaceae family, is an important traditional Chinese medicinal plant. The L. japonica flower (LJF) is widely used in medicine, cosmetics, drinks, and food due to its medicinal and sweet-smelling properties. Considerable efforts have been devoted to investigating the pharmacological activities of LJF; however, the regulatory mechanism of the floral scents remains unknown. We previously selected and bred an elite variety of L. japonica var. chinensis Thunb. called ‘Yujin2’, which has a strong aroma and is used in functional drinks and cosmetics. In order to reveal the regulatory mechanism of the floral scents of LJF, volatile metabolomic and transcriptomic analyses of the LJF at the silver flowering stage of ‘Yujin2’ (strong aroma) and ‘Fengjin1’ (bland odor) were performed. Our results revealed that a total of 153 metabolites and 9,523 genes were differentially regulated in LJF between ‘Yujin2’ and ‘Fengjin1’. The integrated analysis of omics data indicated that the biosynthetic pathways of terpenoids (i.e., monoterpenoids, including geraniol and alpha-terpineol; sesquiterpenoids, including farnesol, farnesal, and alpha-farnesene; triterpenoid squalene), tryptophan and its derivatives (methyl anthranilate), and fatty acid derivatives, were major contributors to the stronger aroma of ‘Yujin2’ compared to ‘Fengjin1’. Moreover, several genes involved in the terpenoid biosynthetic pathway were characterized using quantitative real-time PCR. These results provide insights into the metabolic mechanisms and molecular basis of floral scents in LJF, enabling future screening of genes related to the floral scent regulation, such as alpha-terpineol synthase, geranylgeranyl diphosphate synthase, farnesyl pyrophosphate synthase, anthranilate synthase, as well as transcription factors such as MYB, WRKY, and LFY. The knowledge from this study will facilitate the breeding of quality-improved and more fragrant variety of L. japonica for ornamental purpose and functional beverages and cosmetics.

金银花（Lonicera japonica Thunb.）隶属于忍冬科（Caprifoliaceae），是重要的传统药用植物。其花（以下简称LJF）兼具药用价值与芳香气味，被广泛应用于医药、化妆品、饮品及食品领域。目前已有大量研究聚焦于LJF的药理活性，但关于其花香的调控机制仍有待阐明。本研究前期选育得到忍冬变种（Lonicera japonica var. chinensis Thunb.）的优良品种‘玉金2号’（‘Yujin2’），该品种香气浓郁，可用于功能性饮品及化妆品生产。为阐明LJF花香的调控机制，本研究对香气浓郁的‘玉金2号’与气味平淡的‘丰金1号’（‘Fengjin1’）的银花期LJF进行了挥发性代谢组与转录组联合分析。分析结果显示，‘玉金2号’与‘丰金1号’的LJF间共有153种代谢物与9523个基因存在差异表达调控。组学数据整合分析表明，与‘丰金1号’相比，‘玉金2号’香气更浓郁的主要成因在于其萜类化合物（terpenoids，包括香叶醇与α-松油醇的单萜类、金合欢醇、金合欢醛与α-法尼烯的倍半萜类以及三萜角鲨烯）、色氨酸（tryptophan）及其衍生物（邻氨基苯甲酸甲酯）以及脂肪酸衍生物的生物合成通路存在显著差异。此外，本研究通过实时荧光定量PCR（quantitative real-time PCR）对萜类生物合成通路中的多个关键基因进行了功能表征。上述研究结果阐明了LJF花香形成的代谢机制与分子基础，为后续筛选花香调控相关基因提供了理论依据，包括α-松油醇合酶（alpha-terpineol synthase）、牻牛儿基牻牛儿基二磷酸合酶（geranylgeranyl diphosphate synthase）、法尼基焦磷酸合酶（farnesyl pyrophosphate synthase）、邻氨基苯甲酸合酶（anthranilate synthase）以及MYB、WRKY与LFY等转录因子。本研究的成果将有助于培育品质更优、香气更浓郁的金银花品种，以满足观赏、功能性饮品及化妆品产业的需求。