Abstract 4-Coumaric acid: coenzyme A ligase (4CL) is a key enzyme in the phenylpropanoid metabolic pathway that regulates the biosynthesis of lignin and flavonoids. Therefore, the study of 4CL is important to explore the accumulation and regulation of metabolites. This study investigated the role that the 4CL2 gene from Dryopteris fragrans (Df4CL2) plays in the metabolite synthesis. Changes in gene expression, enzyme activity, and the content of lignin and flavonoids were measured in different tissues of tobacco as model plant that was successfully transferred with Df4CL2. Tobacco plants with Df4CL2 (transgenic tobacco, TT) were successfully obtained via the Agrobacterium-transformation method. This TT tended to be thicker and had an earlier flowering period than wild type tobacco (WT). The expression levels of Df4CL2 were higher in the stem, leaf, and root in TT compared to WT. In addition, compared to WT, TT had higher 4CL enzyme activity and higher lignin and flavonoids contents. This suggests that Df4CL2 is involved in the synthesis of lignin and flavonoids in D. fragrans. This research provides important evidence toward understanding the phenylpropanoid metabolic pathway in ferns.

中文翻译：

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4-香豆酸的功能分析：转基因烟草中香毛蕨的 CoA 连接酶增强木质素和类黄酮

摘要 4-香豆酸：辅酶 A 连接酶 (4CL) 是苯丙素代谢途径中的关键酶，调节木质素和类黄酮的生物合成。因此，4CL的研究对于探索代谢物的积累和调控具有重要意义。本研究调查了鳞毛蕨 (Dryopteris fragrans) 的 4CL2 基因 (Df4CL2) 在代谢物合成中的作用。作为成功转移 Df4CL2 的模型植物，测量了烟草不同组织中基因表达、酶活性以及木质素和黄酮类化合物含量的变化。通过农杆菌转化方法成功获得了带有Df4CL2的烟草植物（转基因烟草，TT）。与野生型烟草 (WT) 相比，这种 TT 往往更厚且花期更早。与 WT 相比，TT 中的茎、叶和根中 Df4CL2 的表达水平较高。此外，与WT相比，TT具有更高的4CL酶活性以及更高的木质素和黄酮类化合物含量。这表明 Df4CL2 参与 D. fragrans 中木质素和类黄酮的合成。这项研究为了解蕨类植物中苯丙素代谢途径提供了重要证据。