不同生长年限巴戟天蒽醌类含量差异比较及转录组学挖掘蒽醌类生物合成相关基因

Comparison of anthraquinone content in Morinda officinalis at different growth years and transcriptomics mining of anthraquinone biosynthesis related genes

目的研究不同生长年限巴戟天Morinda officinalis根部蒽醌类化合物的含量差异及生物合成相关基因。方法采用HPLC测定1年生和6年生巴戟天根中蒽醌类化合物成分,并进行比较转录组分析,采用qRT-PCR验证基因表达结果。结果HPLC检测结果显示在6年生根中蒽醌类物质显著增加,通过比较转录组分析,从1年生和6年生巴戟天的根中筛选到8619条差异表达基因,KEGG分析表明差异基因主要富集在各种次生代谢物的生物合成、苯丙素生物合成、泛醌和其他萜类醌生物合成等通路中。此外,共鉴定到13条蒽醌生物合成途径相关的差异表达Unigenes,其中ICS、SK、CS、DHNA-CoA synthase均在6年生根中上调表达,而DXS、DXR、DAHPS、IDH均下调表达,DHQD/SDH既有上调表达的又有下调表达的Unigenes。进一步选择6个候选基因进行qRT-PCR验证,验证结果与转录组数据一致。结论为鉴别参与巴戟天蒽醌生物合成的相关基因提供参考,为后期进一步深入研究蒽醌类生物合成的累积规律分子机制提供基础数据。

Objective To explore differences of anthraquinones content,the genes related to biosynthesis of anthraquinones in the roots of Bajitian(Morinda officinalis How)in different growth years.Methods The components of anthraquinones by HPLC in the roots of 1-year-old and 6-year-old M.officinalis roots were determined,the transcriptomes were sequenced and compared,genes expression were verified by RT-qPCR.Results The results of HPLC showed that anthraquinones increased significantly after six years of rooting.By comparative transcriptome analysis,8619 differentially expressed genes were screened from 1-year-old and 6-year-old M.officinalis,KEGG analysis showed that the differential genes were mainly concentrated in biosynthesis of various secondary metabolites-part 2,phenylpropanoid biosynthesis,ubiquinone and other terpenoid-quinone biosynthesis and etc.A total of 13 differentially expressed Unigenes were identified from the anthraquinone biosynthesis pathway,the expression of ICS,SK,CS,DHNA-CoA synthase were significantly up-regulated in 6-year-old M.officinalis,DXS,DXR,DAHPS,IDH were significantly down-regulated.DHQD/SDH were up-regulated and down-regulated Unigenes.RT-qPCR was performed on six candidate genes,and the gene expression results were consistent with transcriptome sequencing.Conclusions This experiment provided reference for identifying the relevant genes involved in anthraquinone biosynthesis,and laid the foundation for further in-depth research on the molecular mechanism of accumulation of anthraquinone biosynthesis in M.officinalis.