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 HiSeq^TM 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.