白腐真菌降解麦麸纤维关键基因挖掘

Key genes of wheat bran degradation by White rot fungi

白腐真菌是已知能高效降解木质纤维素的微生物之一,为预测和筛选白腐真菌与麦麸纤维降解有关的基因,对白腐菌A.polytricha 5.584分别以麦麸纤维和葡萄糖为单一碳源的液态培养环境下的转录组进行高通量测序,并利用GO等数据库对转录本进行比较分析。转录组测序共得到38.18 Gb数据,各样品的Clean Reads与参考基因组的比对效率在86.29%~88.85%之间,FPKM密度分布表明分组合理且组间存在差异;使用DEGseq筛选差异表达基因,并与七大功能数据库系统开展比对注释,共得到上调基因8214条,下调基因3882条,其中有8638个被注释到GO数据库,4310个被注释到KEGG数据库;使用DIAMOND软件对差异表达基因进行蛋白互作分析,筛选出互作关系评分≥300的网络关系作图,得到5个与白腐菌降解麦麸纤维相关的重要关键基因:CL16.Contig1_All、CL1024.Contig1_All、CL2915.Contig1_All、CL710.Contig10_All、CL3860.Contig3_All,为深入研究白腐菌对麦麸膳食纤维的降解机制提供参考。

White rot fungi is one of the known microorganisms that can efficiently degrade lignocellulose.In order to predict and screen the genes related to the degradation of wheat bran fiber by White rot fungi,A.polytricha 5.584 was cultured in liquid culture environment with wheat bran fiber and glucose as single carbon source,the transcriptome was sequenced by high-throughput sequencing technology,and the transcripts were compared and analyzed by GO and other databases.A total of 38.18 Gb clean data were obtained from the sequencing results of BGI-500 high-throughput sequencing platform.After recombination and de-redundancy,a total of 31531 unigenes were obtained.The total length,average total length,N50,and its GC concentration were 57226025 bp,1814 bp,2537 bp,and 52.42%,respectively.24404 CDS were detected by transcoder,and 1989 SSRs were also detected to be scattered in 1536 unigenes.The comparison efficiency between clean reads of each sample and the reference genome was 86.29%-89.49%.The FPKM density distribution results showed that the grouping was reasonable and there were differences between groups.By using DEGseq to screen differentially expressed genes and comparing them with the seven functional database systems,8214 up-regulated genes and 3882 down regulated genes were obtained,of which 8638 were annotated into the GO database,and they were marked in 42 secondary en-tries of the three main functional classifications.The number of different gene expression groups annotated to the secondary function of“biological process”function“cell metabolism step(GO:0008152)”was 1088.There were 1111 differential genes annotated to the secondary function groups“membrane(GO:0016020)”of“cell component”function.There were 1818 differential genes annotated to the secondary function“catalytic activity(GO:0003824)”of“gene molecular structure and function”,and 4310 differ-entially expressed genes were annotated into KEGG database.Finally,the protein interaction of differenti-ally expressed genes was analyzed by using diamond software,and the network relationship with interaction relationship score greater than or equal to 300 was selected for mapping.Five key genes related to the deg-radation of wheat bran fiber were obtained include CL16.Contig1_All、CL1024.Contig1_All、CL2915.Contig1_All、CL710.Contig10_All and CL3860.Contig3_All.This study provides a reference for the in-depth study of the degradation mechanism of White rot fungi on wheat bran dietary fiber.