Li Yongpeng, Zhou Qin, Fan Xiaoxuan, Wang Yao, Wang Can, Ruan Qingyan, Wu Zhihan, Shao Lili, Li Liqin, Sheng Miaomiao, Tang Xuchong, Chen Hongkun, Hao Xiaolong, Kai Guoyin
Zhejiang Provincial TCM Key Laboratory of Chinese Medicine Resource Innovation and Transformation, Zhejiang International Science and Technology Cooperation Base for Active Ingredients of Medicinal and Edible Plants and Health, Jinhua Academy, School of Pharmaceutical Sciences, Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China.
Key Laboratory of Traditional Chinese Medicine for the Development and Clinical Transformation of Immunomodulatory Traditional Chinese Medicine in Zhejiang Province, Huzhou Central Hospital, the Fifth School of Clinical Medicine of Zhejiang Chinese Medical University, Hangzhou 310053, China.
Int J Biol Macromol. 2025 Jul;318(Pt 3):145253. doi: 10.1016/j.ijbiomac.2025.145253. Epub 2025 Jun 13.
As a leading cause of death worldwide, cancer severely threatens human health and life. Camptothecin, a plant-derived monoterpene indole alkaloid (MIA) has been extensively used to treat various cancers. However, the camptothecin production in its plants sources is low and cannot meet the global need. Identifying enzyme-encoding genes related to camptothecin biosynthesis could provide parts for the reconstruction of camptothecin biosynthetic pathway in heterologous systems using synthetic biology tools, thus guaranteeing the camptothecin supply. In this study, 15 10-hydroxygeraniol oxidoreductases (10HGOs) were genome-wide identified in O. pumila, and three Op10HGOs namely Op10HGO1, Op10HGO2, and Op10HGO3 were subjected to the enzymatic activity assays. Op10HGO2 and Op10HGO3 exhibited the ability to convert 10-hydroxygeraniol into 10-oxogeraniol, 10-oxogeranial, and 10-hydroxygeranial in the presence of NADP, whereas Op10HGO1 catalyzed the production of 10-oxogeraniol and 10-hydroxygeranial. Overexpression of Op10HGO2 led to increased camptothecin content in Ophiorrhiza pumila hairy roots, whereas knock-out of Op10HGO2 markedly decreased the camptothecin content, indicating its important roles in the biosynthesis of camptothecin. This work provided a candidate gene for enhancing the camptothecin production in O. pumila using transgenic approaches, as well as offered available DNA parts for reconstructing the MIAs biosynthetic pathway.
作为全球主要死因之一，癌症严重威胁着人类健康和生命。喜树碱是一种植物源单萜吲哚生物碱（MIA），已被广泛用于治疗各种癌症。然而，其植物来源中喜树碱的产量较低，无法满足全球需求。鉴定与喜树碱生物合成相关的酶编码基因可为利用合成生物学工具在异源系统中重建喜树碱生物合成途径提供元件，从而保证喜树碱的供应。在本研究中，在海南蛇根草中全基因组鉴定了15个10-羟基香叶醇氧化还原酶（10HGO），并对其中三个Op10HGO，即Op10HGO1、Op10HGO2和Op10HGO3进行了酶活性测定。在NADP存在的情况下，Op10HGO2和Op10HGO3表现出将10-羟基香叶醇转化为10-氧代香叶醇、10-氧代香叶醛和10-羟基香叶醛的能力，而Op10HGO1催化生成10-氧代香叶醇和10-羟基香叶醛。Op10HGO2的过表达导致海南蛇根草毛状根中喜树碱含量增加，而敲除Op10HGO2则显著降低喜树碱含量，表明其在喜树碱生物合成中起重要作用。这项工作为利用转基因方法提高海南蛇根草中喜树碱产量提供了一个候选基因，也为重建MIA生物合成途径提供了可用的DNA元件。
