Li Cuiping, Huang Kaiyong, Li Kuipeng
Key Laboratory of National Forestry and Grassland Administration on Cultivation of Fast-Growing Timber in Central South China, Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, China.
Guangxi Key Laboratory of Superior Timber Trees Resource Cultivation, Guangxi Forestry Research Institute, Nanning, China.
Sci Rep. 2025 Jul 24;15(1):26896. doi: 10.1038/s41598-025-10524-x.
Cunninghamia lanceolata, a coniferous timber species solely endemic to China, possesses a natural variant known as Red-heart Chinese fir. This variant is renowned for the distinctive color of its heartwood, where the chestnut-brown xylem significantly enhances the economic value of Cunninghamia lanceolata. To uncover the mechanism of heartwood formation for Red-heart Chinese fir, we conducted a combined analysis of the metabolome and transcriptome during the radial alteration of mature Red-heart Chinese fir xylem. It was determined that the transition zone serves as a critical site for the transformation of primary metabolites to secondary metabolites without the xylem of mature red cedar. Additionally, we demonstrated that increasing tree age enriches the metabolites of the heartwood of red cedar to the downstream products of the biosynthetic pathway of flavonoids. Pelargonidin and Tricetin are the key substances for the colour development of the heartwood of mature Red-heart Chinese, and WRKY, MYB, LOB, GRAS, and AP2 are transcription factors that potentially play pivotal roles in regulating flavonoid biosynthesis. This study provides novel insights into the molecular regulatory mechanisms underlying heartwood formation in forest trees.
杉木是中国特有的针叶用材树种，有一个天然变种叫红心杉木。该变种以其心材独特的颜色而闻名，其中栗褐色的木质部显著提高了杉木的经济价值。为了揭示红心杉木心材形成的机制，我们对成熟红心杉木木质部径向变化过程中的代谢组和转录组进行了联合分析。结果表明，过渡区是初级代谢产物向次生代谢产物转化的关键部位，而成熟红杉的木质部中没有这种转化。此外，我们还证明，树龄的增加使红杉心材的代谢产物丰富到类黄酮生物合成途径的下游产物。天竺葵素和三丁基锡是成熟红心杉木心材颜色形成的关键物质，WRKY、MYB、LOB、GRAS和AP2是可能在调节类黄酮生物合成中起关键作用的转录因子。本研究为林木心材形成的分子调控机制提供了新的见解。
