基于代谢组学和转录组学解析不同品系黄果枸杞黄酮类化合物积累机理

Mechanism Analysis of Flavonoid Accumulation in Different Strains of Yellow Goji Based on Metabolomics and Transcriptomics

摘要:

为探讨黄果枸杞(Lycium barbarum var. auranticarpum)黄酮类化合物生物合成的调控网络，利用广泛靶向代谢组学技术和转录组学分析黄果枸杞和杂交黄果枸杞的差异代谢物和差异表达基因。结果表明，55种黄酮类化合物在杂交黄果枸杞果实中含量较高，其中黄酮醇(63种)和二氢黄酮(13种)类化合物占主导(60.09%)。通过筛选黄酮类化合物生物合成相关途径差异代谢物表明，肉桂酸、圣草素和二氢槲皮素等化合物在杂交黄果枸杞中含量较高，而槲皮素和表儿茶素仅在杂交黄果枸杞中存在。黄果枸杞和杂交黄果枸杞中共检测到23 244个基因差异表达，14 129个基因在杂交黄果枸杞中表达上调，9 115个基因下调。筛选出黄酮类化合物生物合成相关途径差异表达结构基因11条，杂交黄果枸杞中共有7个参与黄酮类化合物生物合成的关键结构基因(LbANS、LbF3′H、LbF3′5′H、Lb4CL、LbDFR、LbPAL和LbFLS)的表达量均高于黄果枸杞。同时，4条MYB转录因子在杂交黄果枸杞中表达上调。因此，这些关键结构基因和转录因子可能是调控黄果枸杞和杂交黄果枸杞黄酮代谢物差异积累的关键基因。

Abstract:

To explore the regulatory network of flavonoid biosynthesis in Lycium barbarum var. auranticarpum, we utilized broad-target metabolomics and transcriptomics to analyze the differential metabolites and differentially expressed genes between L. barbarum var. auranticarpum (yellow goji) and its hybrid (hybrid yellow goji). The results showed that 55 kinds of flavonoids were present in higher amounts in the fruits of hybrid yellow goji, among which flavonols (63) and dihydroflavones (13) were dominant (60.09%). By screening the differential metabolites in the flavonoid biosynthesis-related pathways, it was found that cinnamic acid, swertiamarin and dihydroquercetin were present in higher amounts in hybrid yellow goji, while quercetin and epicatechin were only present in hybrid yellow goji. A total of 23 244 differentially expressed genes were detected in yellow goji and hybrid yellow goji, with 14 129 genes upregulated and 9 115 genes downregulated in hybrid yellow goji. Eleven differentially expressed structural genes related to the flavonoid biosynthesis pathway were screened out. The expression of seven key structural genes (LbANS, LbF3′H, LbF3′5′H, Lb4CL, LbDFR, LbPAL and LbFLS) involved in flavonoid biosynthesis were all higher in hybrid yellow goji than in yellow goji. Meanwhile, four MYB transcription factors were upregulated in hybrid yellow goji. Therefore, these key structural genes and transcription factors may be the key genes regulating the differential accumulation of flavonoids in yellow goji and hybrid yellow goji.