State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
China National Botanical Garden, Beijing, 100093, China.
BMC Plant Biol. 2024 May 7;24(1):370. doi: 10.1186/s12870-024-05078-5.
Nymphaea (waterlily) is known for its rich colors and role as an important aquatic ornamental plant globally. Nymphaea atrans and some hybrids, including N. 'Feitian 2,' are more appealing due to the gradual color change of their petals at different flower developmental stages. The petals of N. 'Feitian 2' gradually change color from light blue-purple to deep rose-red throughout flowering. The mechanism of the phenomenon remains unclear.
In this work, flavonoids in the petals of N. 'Feitian 2' at six flowering stages were examined to identify the influence of flavonoid components on flower color changes. Additionally, six cDNA libraries of N. 'Feitian 2' over two blooming stages were developed, and the transcriptome was sequenced to identify the molecular mechanism governing petal color changes. As a result, 18 flavonoid metabolites were identified, including five anthocyanins and 13 flavonols. Anthocyanin accumulation during flower development is the primary driver of petal color change. A total of 12 differentially expressed genes (DEGs) in the flavonoid biosynthesis pathway were uncovered, and these DEGs were significantly positively correlated with anthocyanin accumulation. Six structural genes were ultimately focused on, as their expression levels varied significantly across different flowering stages. Moreover, 104 differentially expressed transcription factors (TFs) were uncovered, and three MYBs associated with flavonoid biosynthesis were screened. The RT-qPCR results were generally aligned with high-throughput sequencing results.
This research offers a foundation to clarify the mechanisms underlying changes in the petal color of waterlilies.
睡莲以其丰富的色彩和作为全球重要水生观赏植物的作用而闻名。由于其花瓣在不同的花发育阶段逐渐变色，因此 Atras 睡莲和一些杂交种，包括 N. 'Feitian 2'，更具吸引力。N. 'Feitian 2'的花瓣在整个开花过程中逐渐从浅蓝色变为深玫瑰红色。该现象的机制尚不清楚。
本工作研究了 N. 'Feitian 2' 在六个开花阶段花瓣中的类黄酮，以确定类黄酮成分对花色变化的影响。此外，还构建了 N. 'Feitian 2' 在两个开花阶段的六个 cDNA 文库，并对其转录组进行测序，以鉴定控制花瓣颜色变化的分子机制。结果鉴定出 18 种类黄酮代谢物，包括 5 种花青素和 13 种类黄酮醇。花发育过程中花青素的积累是花瓣颜色变化的主要驱动因素。总共发现了 12 个在类黄酮生物合成途径中差异表达的基因（DEGs），这些 DEGs 与花青素积累呈显著正相关。最终重点关注了 6 个结构基因，因为它们在不同的开花阶段的表达水平差异很大。此外，还发现了 104 个差异表达的转录因子（TFs），并筛选出与类黄酮生物合成相关的三个 MYB。RT-qPCR 结果与高通量测序结果基本一致。
本研究为阐明睡莲花瓣颜色变化的机制提供了基础。
