目的 通过权重基因共表达网络分析(weighted gene co-expression network analysis,WGCNA)挖掘人参皂苷Rh₁生物合成相关基因。方法 以种植于吉林省人参主产区304个农家品种的转录组测序数据为基础,以人参皂苷Rh₁含量为表型进行差异表达基因的挖掘。结果 通过WGCNA获得6个与人参皂苷Rh₁含量密切相关的基因共表达模块,根据关联分析结果确定Green模块为与人参皂苷Rh₁含量显著相关的关键模块。功能注释结果显示Green模块内的基因富集到mRNA结合、蛋白修饰等多个相关途径。通过构建基因互作网络筛选获得7个核心基因,功能预测表明这些基因可能在人参皂苷Rh₁的生物合成途径中起着重要作用。对7个候选基因进行茉莉酸甲酯(methyl jasmonate,MeJA)体外调控分析。对人参不定根进行MeJA诱导处理,随MeJA的诱导,comp9517_c0_seq1、comp10896_c0_seq1、comp43180_c0_seq2、comp64014_c0_seq8的表达量与人参皂苷Rh₁的含量同时呈现显著变化,但只有comp64014_c0_seq8的表达趋势与人参皂苷Rh₁在MeJA诱导下的表达趋势相同,表明这条候选基因可能与人参皂苷Rh₁的合成密切相关。结论 为人参皂苷Rh₁生物合成途径的解析提供了理论基础。

Objective The aim of this study is to unearth genes associated with the biosynthesis of ginsenoside Rh₁ employ through weighted gene co-expression network analysis (WGCNA). Methods Utilizing transcriptome sequencing data from 304 distinct domesticated varieties of ginseng cultivated in the primary ginseng-producing region of Jilin Province, China, we conducted a differentially expressed gene mining with ginsenoside Rh₁ content as the phenotypic parameter. Results A total ofsix co-expression modules of genes intimately correlated with ginsenoside Rh₁ content was gained by employing WGCNA. Subsequent correlation analyses highlighted the Green module as a pivotal module significantly associated with ginsenoside Rh₁ content. Functional annotation results revealed that genes within the Green module were enriched in several pathways, including mRNA binding and protein modification. A total of seven core genes were selected by constructing gene interaction network, and functional prediction indicated that these genes may play crucial roles in the biosynthesis pathway of ginsenoside Rh₁. In vitro modulation analysis of methyl jasmonate (MeJA) was performed on these seven candidate genes. Upon MeJA induction in ginseng adventitious roots, the expression levels of comp9517_c0_seq1, comp10896_c0_seq1, comp43180_c0_seq2, and comp64014_c0_seq8 and ginsenoside Rh₁ content exhibited significant simultaneous changes. However, only the expression trend of comp64014_c0_seq8 was the same as that of ginsenoside Rh₁ induced by MeJA, indicating that this candidate gene may be closely related to ginsenoside Rh₁ synthesis. Conclusion This study lays the theoretical foundation for unraveling the biosynthesis pathway of ginsenoside Rh₁.

吉林省科技厅项目（20180101027JC，20200403011SF）；国家自然科学基金青年基金项目（31401445）