Chen Zhiping, Zhou Yongxin, Jiang Xia, Li He, Liu Xiaohui, Deng Lunxiu, Wang Gang
Guizhou Academy of Forestry, Guiyang, Guizhou, 550005, China.
Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern, Guiyang, Guizhou, 550005, China.
BMC Plant Biol. 2025 May 31;25(1):734. doi: 10.1186/s12870-025-06549-z.
Camellia huana, an endangered plant species with a high ornamental and medicinal value, is designated as a Class I protected plant in China. In the natural state, the flowers of C. huana have golden color and fragrance; however, our study group found that the outer layer of the petals of one C. huana plant was mutated and showed red color. Plant petals show a variety colors due to the synthesis and accumulation of pigments. However, thus far, few studies have investigated the formation and differences in flower color in C. huana. Carotenoids are the main color-forming components in C. huana flowers. C. huana petals also contain volatile compounds that impart a distinct fragrance to the flowers. In the present study, to better understand the regulatory mechanisms of carotenoids and volatile compounds in the petals of C. huana flowers of different colors, we used flowers obtained at different developmental periods of C. huana as the experimental materials and conducted metabolome and transcriptome analyses.
The results showed that C. huana is rich in volatile compounds. A total of 372 metabolites were detected in C. huana, which mainly included 72 terpenoids, 67 heterocyclic compounds, nitrogen-containing compounds, esters, aromatic hydrocarbons, 39 alcohols, and others; terpenoids, heterocyclic compounds, and esters were the predominant volatiles. Forty carotenoids were identified by carotenoid content analysis, and 10 genes were involved in carotenoid biosynthesis were screened for their significant differential expression, namely 15-cis-phytoene synthase (crtB), prolycopene isomerase (crtISO, crtH), beta-carotene 3-hydroxylase (crtZ), beta-carotene isomerase (DWARF27), 9-cis-beta-carotene 9',10'-cleaving dioxygenase (CCD7), zeaxanthin epoxidase (ZEP, ABA1), 9-cis-epoxycarotenoid dioxygenase (NCED), xanthoxin dehydrogenase (ABA2), abscisate beta-glucosyltransferase (AOG), and (+)-abscisic acid 8'-hydroxylase (CYP707A). A total of 12,089 differential genes were screened by transcriptome analysis.
The results of this study enriched the transcriptome data and provided new insights into the mechanisms of color and odor formation in the flowers of C. huana.
金花茶是一种具有较高观赏和药用价值的濒危植物，在中国被列为国家一级保护植物。在自然状态下，金花茶的花朵呈金黄色且具有香味；然而，我们的研究小组发现一株金花茶植物花瓣的外层发生了变异，呈现出红色。植物花瓣由于色素的合成和积累而呈现出多种颜色。然而，迄今为止，很少有研究调查金花茶花朵颜色的形成及其差异。类胡萝卜素是金花茶花朵中主要的呈色成分。金花茶花瓣还含有挥发性化合物，赋予花朵独特的香味。在本研究中，为了更好地了解不同颜色金花茶花瓣中类胡萝卜素和挥发性化合物的调控机制，我们以不同发育时期的金花茶花朵为实验材料，进行了代谢组和转录组分析。
结果表明，金花茶富含挥发性化合物。在金花茶中共检测到372种代谢物，主要包括72种类萜、67种杂环化合物、含氮化合物、酯类、芳香烃、39种醇类等；类萜、杂环化合物和酯类是主要的挥发性成分。通过类胡萝卜素含量分析鉴定出40种类胡萝卜素，并筛选出10个参与类胡萝卜素生物合成且表达有显著差异的基因，即15-顺式-八氢番茄红素合酶（crtB）、原番茄红素异构酶（crtISO、crtH）、β-胡萝卜素3-羟化酶（crtZ）、β-胡萝卜素异构酶（DWARF27）、9-顺式-β-胡萝卜素9',10'-裂解双加氧酶（CCD7）、玉米黄质环氧化酶（ZEP、ABA1）、9-顺式-环氧类胡萝卜素双加氧酶（NCED）、黄质醛脱氢酶（ABA2）、脱落酸β-葡萄糖基转移酶（AOG）和（+）-脱落酸8'-羟化酶（CYP707A）。通过转录组分析共筛选出12089个差异基因。
本研究结果丰富了转录组数据，为金花茶花朵颜色和气味形成机制提供了新的见解。
