多花黄精根茎的转录组分析与甾体皂苷生物合成相关基因发掘

Transcriptome analysis of rhizome of Polygonatum cyrtonema and identification of candidate genes involved in biosynthetic pathway of steroidal saponin

为了丰富多花黄精Polygonatum cyrtonema幼苗期根茎发育的转录组数据,发掘参与甾体皂苷生物合成的功能基因,为多花黄精活性成分的合成代谢途径与调控机制研究提供遗传资源,该研究基于Illumina深度测序平台,对多花黄精幼苗期根茎进行转录组测序及生物信息学分析,包括序列数据的组装拼接、unigene序列的功能注释、分类和代谢途径分析,并对次生代谢途径中甾体皂苷的生物合成通路进行深入解析。结果显示,多花黄精根茎的转录组数据经拼接共产生了126 546条unigene序列,其中47 226条被注释。共有16 499条unigene被定位到了KEGG数据库中的132个代谢通路,其中2 768条被鉴定出参与了22个次生代谢物生物合成通路。鉴定出的113条unigene序列,分别编码27个与甾体皂苷生物合成相关的代谢酶,与45个拟南芥酶基因同源。该研究从多花黄精转录组数据库中发掘到一系列与活性成分甾体皂苷生物合成相关的酶基因,对这些基因的深入研究,有助于从分子水平上解析多花黄精中甾体皂苷的生物合成途径。该研究也为多花黄精的转录组学研究提供了丰富的参考数据,对于多花黄精的功能基因组学研究具有重要意义。

To enrich the transcriptome data in rhizome of Polygonatum cyrtonema seedlings, identify candidate functional genes involved in steroidal saponin biosynthesis and provide genetic resources for the research on anabolism pathway and regulatory mechanism of active components in P. cyrtonema, Illumina platform was applied to perform transcriptomic sequencing of rhizome of P. cyrtonema, followed by a series of bioinformatics analysis on RNA-seq data, including de novo assembly, annotation, classification and metabolic pathway analysis of the assembled unigene. Meanwhile, a deep analysis on the steroidal saponin biosynthesis in secondary metabolism pathway was performed. The results showed a total of 126 546 unigene were obtained by de novo transcriptome assembly, of which 47 226 were annotated. Of these, 16 499 unigene were mapped to 132 specific pathways, of which 2 768 were identified to be involved in 22 secondary metabolic pathways. One hundred and thirteen unigene were identified from the transcriptome database, which encoded 27 metabolic enzymes associated with steroidal saponin biosynthesis and shared similarity with 45 functional genes in Arabidopsis thaliana. In conclusion, a series of candidate functional genes, which might be involved in steroidal saponin biosynthesis, were selected from the transcriptome database of P. cyrtonema rhizome. Further investigation of these candidate genes will provide insight into their actual functions in the steroidal saponin biosynthetic pathway in P. cyrtonema. In addition, this study also provide abunant reference data for transcriptome characterization of P. cyrtonema and has important significance for functional genomics of P. cyrtonema.