Table3_Metabolomic and transcriptomic analyses jointly reveal the mechanism underlying the reddening of Chimonanthus praecox stamens.xlsx

IntroductionFlower characteristics are crucial ornamental and reproductive traits in Chimonanthus praecox. Over its long cultivation history, variations have been observed in the oral organs, primarily in the petals, with limited reports on stamen traits. Stamen variation, integral to the mating system, can enhance the plant’s ornamental value and directly impact its reproductive success.MethodsThis study is the first to report the phenomenon of red coloration in C. praecox stamens. Using UPLC-MS/MS, we analyzed the types and quantities of major metabolites in stamens of different colors.ResultsOur results indicated that the red coloration was primarily due to the accumulation 42 on of high levels of anthocyanins, specifically cyanidin 3-O-rutinoside and cyanidin 3-O-glucoside. Transcriptomic sequencing identified 63 differentially expressed genes (DEGs) related to the anthocyanin biosynthetic pathway, most showing peak expression during the bud stage. The results of the metabolite analysis and transcriptomic sequencing were similar to those of previous studies on petal reddening, suggesting a close relationship between the mechanisms of stamen and petal reddening.DiscussionThis study elucidated the mechanism of stamen reddening in C. praecox, expanding the species’ genetic resources and offering insights into color changes across oral tissue.

Chimonanthus praecox的花朵特征在观赏与繁殖方面至关重要。历经漫长的栽培历史，该物种在花被等口器器官上出现了多种变异，然而关于雄蕊性状的报道则相对匮乏。雄蕊的变异，作为交配系统的重要组成部分，不仅能够提升植物的观赏价值，而且对植物的繁殖成功率产生直接影响。

本研究首次报道了C. praecox雄蕊呈现红色现象。通过液相色谱-串联质谱法（UPLC-MS/MS），我们分析了不同颜色雄蕊中主要代谢物的类型与含量。

研究结果显示，红色主要由花青素（尤其是氰苷3-O-芸香糖苷和氰苷3-O-葡萄糖苷）的高浓度积累所致。转录组测序鉴定出与花青素生物合成途径相关的63个差异表达基因（DEGs），其中大多数基因在花蕾期达到峰值表达。代谢物分析与转录组测序的结果与先前关于花瓣变红的研究结果相似，这表明雄蕊与花瓣变红机制之间存在密切联系。

讨论部分中，本研究揭示了C. praecox雄蕊变红的机制，丰富了该物种的遗传资源，并为口组织颜色变化提供了新的见解。