Yu Xiaochen, Yu Jinghui, Liu Sizhang, Liu Mingming, Wang Kangyu, Zhao Mingzhu, Wang Yanfang, Chen Ping, Lei Jun, Wang Yi, Zhang Meiping
College of Life Science, Jilin Agricultural University, Changchun 130118, China.
Jilin Engineering Research Center Ginseng Genetic Resources Development and Utilization, Changchun 130118, China.
Plants (Basel). 2024 Feb 23;13(5):604. doi: 10.3390/plants13050604.
as a traditional medicinal plant with a long history of medicinal use. Ginsenoside Ro is the only oleanane-type ginsenoside in ginseng, and has various pharmacological activities, including anti-inflammatory, detoxification, and antithrombotic activities. UDP-dependent glycosyltransferase (UGT) plays a key role in the synthesis of ginsenoside, and the excavation of UGT genes involved in the biosynthesis of ginsenoside Ro has great significance in enriching ginsenoside genetic resources and further revealing the synthesis mechanism of ginsenoside. In this work, ginsenoside-Ro-synthesis-related genes were mined using the reference-free transcriptome database. Fourteen hub transcripts were identified by differential expression analysis and weighted gene co-expression network analysis. Phylogenetic and synteny block analyses of , a transcript among the hub transcripts, showed that belonged to the subfamily and was relatively conserved in ginseng plants. Functional analysis showed that encodes a glucuronosyltransferase that catalyzes the glucuronide modification of the C3 position of oleanolic acid using uridine diphosphate glucuronide as the substrate. Furthermore, the mutation at 622 bp of its open reading frame resulted in amino acid substitutions that may significantly affect the catalytic activity of the enzyme, and, as a consequence, affect the biosynthesis of ginsenoside Ro. Results of the in vitro enzyme activity assay of the heterologous expression product in of verified the above analyses. The function of was further verified by the result that its overexpression in ginseng adventitious roots significantly increased the content of ginsenoside Ro. The present work identified a new gene involved in the biosynthesis of ginsenoside Ro, which not only enriches the functional genes in the ginsenoside synthesis pathway, but also provides the technical basis and theoretical basis for the in-depth excavation of ginsenoside-synthesis-related genes.
作为一种有着悠久药用历史的传统药用植物。人参皂苷Ro是人参中唯一的齐墩果烷型人参皂苷，具有多种药理活性，包括抗炎、解毒和抗血栓活性。UDP依赖性糖基转移酶（UGT）在人参皂苷的合成中起关键作用，挖掘参与人参皂苷Ro生物合成的UGT基因对于丰富人参皂苷遗传资源和进一步揭示人参皂苷的合成机制具有重要意义。在这项工作中，利用无参考转录组数据库挖掘与人参皂苷-Ro-合成相关的基因。通过差异表达分析和加权基因共表达网络分析鉴定出14个核心转录本。对核心转录本中的一个转录本进行系统发育和共线性分析，结果表明该转录本属于亚家族，在人参植株中相对保守。功能分析表明，该转录本编码一种葡糖醛酸基转移酶，该酶以尿苷二磷酸葡糖醛酸为底物催化齐墩果酸C3位的葡糖醛酸化修饰。此外，其开放阅读框622 bp处的突变导致氨基酸替换，这可能会显著影响该酶的催化活性，进而影响人参皂苷Ro的生物合成。对该转录本在大肠杆菌中的异源表达产物进行体外酶活性测定的结果验证了上述分析。通过在人参不定根中过表达该转录本显著提高人参皂苷Ro含量的结果进一步验证了其功能。本研究鉴定出一个参与人参皂苷Ro生物合成的新基因，这不仅丰富了人参皂苷合成途径中的功能基因，也为人参皂苷合成相关基因的深入挖掘提供了技术基础和理论依据。
