青花菜花蕾转录组测序分析及蜡粉合成相关基因挖掘

【目的】对青花菜花蕾进行转录组测序分析,并挖掘与蜡粉合成相关基因,为探明青花菜花球表面蜡粉形成的分子机制提供理论参考。【方法】分别提取野生型和蜡粉缺失型青花菜花球总RNA,采用Illumina HiSeqTM 2500平台进行转录组测序,获得高质量Clean reads,采用Trinity进行序列组装后获得青花菜Unigene库,将获得的Unigene序列与Nr、Nt、KEGG、Pfam、KOG/COG、Swiss-Prot和GO数据库比对,获得基因功能注释信息;使用DESeq2进行差异表达分析。【结果】共获得44.68 Gb Clean data,De novo组装得到41244条Unigenes,N50长度为1847 bp。从所获得的Unigenes中筛选出8685个差异表达基因（DEGs）（上调基因5747个,下调基因2938个）,共有8038个基因被注释到不同数据库,其中,5220个基因注释到Pfam数据库; 2066个基因注释到COG数据库,3866个基因注释到KOG数据库; 2580个差异表达基因被注释到75个转录因子家族中,注释最多的是MYB家族（235个）;GO数据库中6095个差异表达基因注释到细胞组分、分子功能和生物学过程三大类的52个功能分类; KEGG数据库中,1671个差异表达基因富集到138条代谢通路,其中13个差异表达基因与脂肪酸合成有关,7个差异表达基因与蜡粉生物合成途径有关。【结论】转录因子MYB家族在调控青花菜蜡粉合成中发挥重要作用。蜡粉合成过程中相关酶基因的差异表达是调控青花菜蜡粉合成的关键,尤其是野生型和蜡粉缺失突变体中特异性表达的差异表达基因,可作为后续研究青花菜花球表面蜡粉形成分子机制的对象。

Transcriptome analysis and mining of genes related to wax powder synthesis of broccoli flower buds

【Objective】To perform transcriptome sequencing on broccoli buds,and mine their genes related to wax powder synthesis,so as to lay a foundation for the discovery of the molecular mechanism of wax powder formation on the surface of broccoli spherules.【Method】Total RNA from wild-type and wax-powder-deficient broccoli flower bulbs was extracted,and Illumina HiSeqTM 2500 platform was used for transcriptomes sequencing to obtain high-quality Clean reads,and Trinity software was used for sequence assembly to obtain the broccoli Unigene library. The obtained Unigenes sequence was compared with that in Nr,Nt,KEGG,Pfam,KOG/COG,Swiss-Prot,GO databases to obtain gene function annotation information;DESeq2 software was used for differential expression analysis.【Result】 A total of 44.68 Gb Clean data was generated. And 41244 unigenes with N50 length of 1847 bp,were obtained by De novo assembly method. 8685 differentially expressed genes(DEGs) (5747 up-regulated genes and 2938 down-regulated genes)were obtained in the unigenes,of which 8038 had annotated information. Of these,5220 genes were annotated to the Pfam database;2066 genes annotated to COG database and 3866 genes annotated to KOG database annotation analysis showed that 36230 unigenes had homologens in different public protein databases. A total of 2580 DEGs were annotated to 75 transcription factor families,and the most annotated was MYB family(235). In GO database,6095 DEGs were annotated to 52 functional groups in three categories:cell components,molecular functions and biological processes. In KEGG database, 1671 DEGs were classified into 138 metabolic pathway branches,and 13 DEGs were annotated to fatty acid synthesis related pathway,and 7 DEGs were annotated to wax powder biosynthesis related pathway.【Conclusion】 The MYB family of transcription factors plays an important role in the regulation of wax powder synthesis in broccoli. The differential expression of related enzyme genes during wax powder synthesis is the key to regulating wax powder synthesis in broccoli. In particular,the DEGs in wild-type and wax powder-deficient mutants can be used for further study on the molecular mechanism of wax powder formation on the surface of broccoli.