Li Yueling, Sun Zhongshuai, Lu Jieyang, Jin Zexin, Li Junmin
Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou, China.
Institute of Ecology, Taizhou University, Taizhou, China.
Front Plant Sci. 2023 Feb 20;14:1044581. doi: 10.3389/fpls.2023.1044581. eCollection 2023.
Rehd., commonly known as "seven-son flower," is an ornamental species with a beautiful flower pattern and persistent sepals. Its sepals are of horticultural value, turning bright red and elongating in the autumn; however, the molecular mechanisms that cause sepal color change remain unclear. We analyzed the dynamic changes in anthocyanin composition in the sepal of at four developmental stages (S1-S4). A total of 41 anthocyanins were detected and classified into 7 major anthocyanin aglycones. High levels of the pigments cyanidin-3,5-O-diglucoside, cyanidin-3-O-galactoside, cyanidin-3-O-glucoside, and pelargonidin-3-O-glucoside were responsible for sepal reddening. Transcriptome analysis revealed 15 differentially expressed genes involved in anthocyanin biosynthesis that were detected between 2 developmental stages. Of these, the high expression of was considered critical structural gene related to anthocyanin biosynthesis pathway in the sepal through co-expression analysis with anthocyanin content. In addition, a transcription factor (TF)-metabolite correlation analysis revealed that three HmMYB, two HmbHLH, two HmWRKY, and two HmNAC TFs exhibited a strong positive role in the regulation of the anthocyanin structural genes (Pearson's correlation coefficient > 0.90). Luciferase activity assay showed that HmMYB114, HmbHLH130, HmWRKY6, and HmNAC1 could activate the promoters of and genes . These findings increase our understanding of anthocyanin metabolism in the sepal of and provide a guide for studies involving sepal color conversion and regulation.
七子花（Rehd.），通常被称为“七叶花”，是一种具有美丽花型和宿存萼片的观赏植物。其萼片具有园艺价值，在秋季会变成鲜红色并伸长；然而，导致萼片颜色变化的分子机制仍不清楚。我们分析了七子花萼片在四个发育阶段（S1 - S4）花青素组成的动态变化。共检测到41种花青素，并将其分为7种主要花青素苷元。高水平的色素矢车菊素 - 3,5 - O - 二葡萄糖苷、矢车菊素 - 3 - O - 半乳糖苷（原文此处有误，应为矢车菊素 - 3 - O - 葡萄糖苷）、矢车菊素 - 3 - O - 葡萄糖苷和天竺葵素 - 3 - O - 葡萄糖苷导致萼片变红。转录组分析揭示了在两个发育阶段之间检测到的15个参与花青素生物合成的差异表达基因。其中，通过与花青素含量的共表达分析，认为某基因（原文此处未明确基因名称）的高表达是萼片中与花青素生物合成途径相关的关键结构基因。此外，转录因子（TF） - 代谢物相关性分析表明，三个HmMYB、两个HmbHLH（原文此处有误，应为两个HmMYB）、两个HmWRKY和两个HmNAC转录因子在花青素结构基因的调控中发挥了强烈的正向作用（皮尔逊相关系数> 0.90）。荧光素酶活性测定表明，HmMYB114、HmbHLH130、HmWRKY6和HmNAC1可以激活某基因（原文此处未明确基因名称）和某基因（原文此处未明确基因名称）的启动子。这些发现增进了我们对七子花萼片中花青素代谢的理解，并为涉及萼片颜色转化和调控的研究提供了指导。 （原文中存在一些表述不严谨或错误的地方，已在翻译中尽量按照合理推测进行修正）
