威氏绿绒蒿花色形成过程的转录组分析

Transcriptome Analysis of Petal Color Formation of Meconopsis wilsonii

为明确威氏绿绒蒿花色变化的机制,本研究以威氏绿绒蒿(Meconopsis wilsonii)为实验对象,选择花蕾期、开裂期及全展期3个阶段的花瓣进行转录组测序,根据各发育期基因差异表达的特点,筛选出与花色变化相关基因。采用荧光定量RT-qPCR对差异表达基因进行验证,结果显示,花瓣转录组测序共生成153 596个unigene,平均长度为1 372 bp。通过KEGG、GO数据库的注释,有134条基因注释到与花色相关的合成通路—类黄酮代谢通路中。针对unigene完成相关序列预测工作,产生的CDS总量为80 240个。花蕾期、开裂期及全展期间两两比较显示,开裂期相对于花蕾期有15 064个基因上调,49 153个基因下调、全展期相对花蕾期有19 732个基因上调,42 890个基因下调、全展期相对开裂期有19 215个基因上调,9 510个基因下调。通过对差异表达基因的代谢通路进行分析,发现在威氏绿绒蒿蓝紫色花色形成过程中不存在飞燕草素合成途径。除此之外还筛选了花青苷合成途径中与花色相关的7个基因,经RT-qPCR实验也表明这些基因在整个过程中的表达模式与RNA-Seq数据呈现出一致性。本研究以期深化对威氏绿绒蒿花色形成的认知,为今后绿绒蒿花色的研究提供理论依据。

In order to understand the mechanism of flower color change in Meconopsis wilsonii,transcriptome sequencing was performed on petals at bud stage,dehiscence stage and full expansion stage.Genes related to flower color change were screened out according to the characteristics of gene differential expression in each developmental stage.The differentially expressed genes were verified by fluorescence quantitative RT-qPCR.The results showed that 153 596 unigenes were generated by petal transcriptome sequencing,with an average length of 1 372 bp.Through the annotation of KEGG and GO database,134 genes were annotated into the synthetic pathway related to flower and color--the flavonoid metabolism pathway.A total of 80 240 CDS were generated by the related sequence prediction for unigene.Compared with bud stage,dehiscence stage and full spreading stage,15 064 genes were upregulated and 49 153 genes were down-regulated in dehiscence stage,19 732 genes were up-regulated and 42 890genes were down-regulated in full spreading stage,19 215 genes were up-regulated and 9 510 genes were downregulated in full spreading stage compared with full spreading stage.By analyzing the metabolic pathways of the differentially expressed genes,it was found that delphinin synthesis pathway did not exist in the formation of the blue purple color of Meconopsis wilsonii.In addition,seven genes related to flower color in the anthocyanin synthesis pathway were screened,and RT-qPCR confirmed that the expression pattern of these genes during the whole process was consistent with the RNA-seq data.The purpose of this study is to deepen the cognition of the pattern formation of Meconopsis wilsonii and to provide theoretical basis for the future research on the pattern and color of Meconopsis vermosi.