金线莲体外抗氧化活性及黄酮醇的合成途径初步研究

In vitro Antioxidant Activity of Anoectochilus roxburghii and Preliminary Investigation of the Synthesis Pathway of Flavonols

为探究金线莲不同组织黄酮醇含量积累途径及与抗氧化性的关系,本研究以浙江金线莲(Ar)和台湾金线莲(Af)的根、茎、叶为材料,进行酚类物质含量、抗氧化活性、转录组学和靶向代谢组的综合分析。结果表明,金线莲不同组织酚类物质含量存在显著差异(叶>茎>根),总抗氧化性分析结果类似。靶向代谢组分析结果表明,在金线莲中黄酮醇苷在类黄酮化合物中占多数,尤其是叶片。根、茎、叶转录组测序共获得166028个非冗余基因,通过比对KEGG等八大数据库,筛选出黄酮醇合成途径的30个差异表达基因,并应用加权基因共表达网络鉴定出3个核心基因、6个MYB转录因子基因、2个O-甲基转移酶(OMT)基因和3个尿苷二磷酸葡萄糖醛酸转移酶(UGT)基因,最后利用实时荧光定量PCR(qRT-PCR)进一步分析了部分基因在不同组织中的表达模式,发现大部分基因在Ar中表达更高。本研究结果为探明金线莲黄酮醇的分子合成途径提供了基础。

To investigate the accumulation pathway of flavonol content in different tissues of Anoectochilus and its relationship with antioxidant properties,the roots,stems,and leaves of Anoectochilus roxburghii(Ar)and Anoectochilus formosanus(Af)were analyzed comprehensively for phenolic content,antioxidant activity,transcriptomics and targeted metabolome.The results showed significant differences among the phenolic content of different tissues of Anoectochilus(leaves>stems>roots),and the total antioxidant analysis showed similar trends.The results of targeted metabolome analysis revealed that flavonol glycosides accounted for the majority of flavonoid compounds in Anoectochilus,especially in the leaves.A total of 166028 non-redundant genes were obtained from roots,stems and leaves transcriptome sequencing,and 30 differentially expressed genes of the flavonol synthesis pathway were screened by comparing eight databases,including KEGG.A weighted gene co-expression network was applied to identify three hub genes,six MYB transcription factors,two O-methyltransferase(OMT)genes,and three uroglucuronide diphosphate glucuronosyltransferase(UGT)genes.The expression patterns of some genes in different tissues were further analysed using quantitative real�time PCR(qRT-PCR),which found that most of the genes are more highly expressed in the Ar.The results of this study provide a basis for the investigation of the molecular synthesis pathway of flavonols in Anoectochilus.