Wang Fang, Li Daihao, Zeng Sixian, Gao Xueqian, Wu Guilan, Huang Di, Cao Zihan, Wang Qin, Yu Rangcai, Fan Yanping
The Research Center for Ornamental Plants, College of Horticulture, South China Agricultural University, Guangzhou, China.
College of Life Sciences, South China Agricultural University, Guangzhou, China.
Physiol Plant. 2025 Jul-Aug;177(4):e70333. doi: 10.1111/ppl.70333.
Pyrethrum parthenium, a perennial herb from the genus Pyrethrum within the Asteraceae family, is known for its potent fragrance and significant economic value. Nevertheless, the mechanisms involved in the synthesis and regulation of its floral fragrance compounds remain unclear. This study used gas chromatography-mass spectrometry (GC-MS) to analyze the volatile compounds in five parts of P. parthenium: tubular flowers, ligulate flowers, sepals, receptacles, and leaves. The results showed that the volatile aromatic components include terpenes such as camphor, α-pinene, camphene, d-limonene, β-caryophyllene, and β-farnesene, with camphor being the main volatile compound. Based on the transcriptome data of tubular flowers of P. parthenium, a terpene synthase gene, PpTPS5, was identified. The results of both in vitro and in vivo enzymatic assays demonstrated that PpTPS5 functions as a bifunctional terpene synthase gene. The qRT-PCR results showed that the gene expression pattern of PpTPS5 is correlated with the release pattern of the corresponding terpene aromatic compounds in P. parthenium. Subcellular localization and inhibitor experiments indicated that PpTPS5 functions in the cytosol. Additionally, dual-luciferase and electrophoretic mobility shift assay (EMSA) assays revealed that PpMYB9 can bind to the promoter of PpTPS5 to regulate the biosynthesis of terpenoids. In conclusion, the results of this study provide a theoretical basis for further exploration of the transcriptional regulation of terpene floral fragrance compounds in P. parthenium.
小白菊是菊科匹菊属的一种多年生草本植物，以其浓郁的香气和重要的经济价值而闻名。然而，其花香化合物的合成和调控机制仍不清楚。本研究采用气相色谱-质谱联用（GC-MS）技术分析了小白菊五个部位（管状花、舌状花、萼片、花托和叶片）中的挥发性化合物。结果表明，挥发性芳香成分包括萜类化合物，如樟脑、α-蒎烯、莰烯、d-柠檬烯、β-石竹烯和β-法呢烯，其中樟脑是主要的挥发性化合物。基于小白菊管状花的转录组数据，鉴定出一个萜类合酶基因PpTPS5。体外和体内酶活性测定结果表明，PpTPS5作为一个双功能萜类合酶基因发挥作用。qRT-PCR结果表明，PpTPS5的基因表达模式与小白菊中相应萜类芳香化合物的释放模式相关。亚细胞定位和抑制剂实验表明，PpTPS5在细胞质中发挥作用。此外，双荧光素酶和电泳迁移率变动分析（EMSA）实验表明，PpMYB9可以与PpTPS5的启动子结合，调控萜类化合物的生物合成。总之，本研究结果为进一步探索小白菊中萜类花香化合物的转录调控提供了理论依据。
