College of Architecture and Urban Planning, Fujian University of Technology, Fuzhou, 350118, China.
College of Biology and Pharmacy, Yulin Normal University, Yulin, 537000, China.
BMC Plant Biol. 2024 Nov 1;24(1):1037. doi: 10.1186/s12870-024-05737-7.
Camellia nitidissima Chi is a popular ornamental plant because of its golden flowers, which contain flavonoids and carotenoids. To understand the regulatory mechanism of golden color formation, the metabolites of C. nitidissima petals at five different developmental stages were detected, a proteome map of petals was first constructed via tandem mass tag (TMT) analysis, and the accuracy of the sequencing data was validated via parallel reaction monitoring (PRM).
Nineteen color components were detected, and most of these components were carotenoids that gradually accumulated, while some metabolites were flavonoids that were gradually depleted. A total of 97,647 spectra were obtained, and 6,789 quantifiable proteins were identified. Then, 1,319 differentially expressed proteins (DEPs) were found, 55 of which belong to the flavonoid and carotenoid pathways, as revealed by pairwise comparisons of protein expression levels across the five developmental stages. Notably, most DEPs involved in the synthesis of flavonoids, such as phenylalanine ammonium lyase and 4-coumarate-CoA ligase, were downregulated during petal development, whereas DEPs involved in carotenoid synthesis, such as phytoene synthase, 1-deoxy-D-xylulose-5-phosphate synthase, and β-cyclase, tended to be upregulated. Furthermore, protein‒protein interaction (PPI) network analysis revealed that these 55 DEPs formed two distinct PPI networks closely tied to the flavonoid and carotenoid synthesis pathways. Phytoene synthase and chalcone synthase exhibited extensive interactions with numerous other proteins and displayed high connectivity within the PPI networks, suggesting their pivotal biological functions in flavonoid and carotenoid biosynthesis.
Proteomic data on the flavonoid and carotenoid biosynthesis pathways were obtained, and the regulatory roles of the DEPs were analyzed, which provided a theoretical basis for further understanding the golden color formation mechanism of C. nitidissima.
金花茶因其金黄色的花朵而成为一种受欢迎的观赏植物，花朵中含有类黄酮和类胡萝卜素。为了了解金黄色形成的调控机制，检测了金花茶花瓣在五个不同发育阶段的代谢产物，首先通过串联质量标签 (TMT) 分析构建了花瓣的蛋白质组图谱，并通过平行反应监测 (PRM) 验证了测序数据的准确性。
检测到 19 种颜色成分，这些成分大部分是逐渐积累的类胡萝卜素，而一些代谢产物是逐渐耗尽的类黄酮。共获得 97647 个光谱，鉴定出 6789 个可定量蛋白质。然后，通过五个发育阶段的蛋白质表达水平的两两比较，发现了 1319 个差异表达蛋白 (DEP)，其中 55 个属于类黄酮和类胡萝卜素途径，这些差异表达蛋白的功能主要与类黄酮和类胡萝卜素的生物合成有关。值得注意的是，大多数参与类黄酮合成的 DEP，如苯丙氨酸氨裂解酶和 4-香豆酸-CoA 连接酶，在花瓣发育过程中下调，而参与类胡萝卜素合成的 DEP，如八氢番茄红素合酶、1-脱氧-D-木酮糖-5-磷酸合酶和 β-环化酶，倾向于上调。此外，蛋白质相互作用 (PPI) 网络分析表明，这 55 个 DEP 形成了两个紧密联系的类黄酮和类胡萝卜素合成途径的独特 PPI 网络。八氢番茄红素合酶和查尔酮合酶与许多其他蛋白质有广泛的相互作用，并在 PPI 网络中表现出高连接性，这表明它们在类黄酮和类胡萝卜素生物合成中具有关键的生物学功能。
获得了类黄酮和类胡萝卜素生物合成途径的蛋白质组数据，并分析了 DEP 的调控作用，为进一步了解金花茶金黄色形成机制提供了理论依据。
