偏肿革裥菌GMC基因家族在木质条件下转录表达分析

Transcriptional Expression Analysis of GMC Gene Family from Lenzites gibbosa under Woody Condition

为揭示偏肿革裥菌(Lenzites gibbosa)在分解木材过程中葡萄糖-甲醇-胆碱氧化还原酶(Glucosemethanol-choline oxidoreductases,GMCs)基因的功能,采用高通量测序技术对L.gibbosa分解木屑过程中0,3,5,7,11 d的菌丝体进行转录组测序,以Count值与校正后的FPKM值为表达量进行基因筛选。分析基因表达量变化情况及在eggNOG,COG,GO,KEGG,NR,SwissProt和Pfam等数据库中的功能注释结果,通过qPCR验证基因表达量。根据基因注释结果共筛选到23个GMCs基因,表达量变化表明其中有9个是差异基因。功能注释及富集结果表明,L.gibbosa的GMCs至少有6种,分别为纤维二糖脱氢酶、葡萄糖氧化酶、吡喃糖脱氢酶、L-山梨糖1-脱氢酶、醇氧化酶、吡喃糖氧化酶,属于CAZy-AA3家族下的4个亚家族,在木材木质素与综纤维素的降解过程中,它们主要参与能量转运和代谢有关的碳代谢、甲烷代谢、氨基酸代谢和脂质代谢;GMCs与木质素降解过程中H_(2)O_(2)的形成有特定关系,可与FAD结合,将初级醇基氧化形成醛并释放H_(2)O_(2),为过氧化物酶提供恒定反应底物。由于能在木质素和纤维素的降解过程中发挥重要的辅助作用,GMCs属于与木材降解相关的重要辅助酶系,为白腐菌中GMC家族在木材降解过程中的功能研究提供了依据。

In order to reveal the function of glucose-methanol-choline oxidoreductases(GMCs)genes of Lenzites gibbosa(Trametes gibbosa)during wood decomposition,transcriptome sequencing was performed on L.gibbosa mycelia at 0,3,5,7 and 11 days during the decomposition of wood chips by high-throughput sequencing technology.Count value and corrected FPKM value of each gene were used as expression levels to screen genes and differentially expressed genes(DEGs)between the samples of non-woody control group and the wood-treated samples at 3,5,7 and 11 d.The changes of gene expression levels and the annotated results in function of genes in eggNOG,COG,GO,KEGG,NR,SwissProt and Pfam databases were analyzed.The expression of five important DEGs was verified by fluorescence quantitative PCR(qPCR).A total of 23 GMC genes were screened based on the gene annotation results,and the change of expression showed that 9 of them were DEGs.Functional annotation and enrichment results showed that at least 6 kinds of GMCs in L.gibbosa,namely cellobiose dehydrogenase,glucose oxidase,pyranose dehydrogenase,L-sorbose 1-dehydrogenase,alcohol oxidase and pyranose oxidase,belonged to four subfamilies of CAZy-AA3 family.In the process of wood lignin and holocellulose degradation,they were mainly involved in carbon metabolism,methane metabolism,amino acid metabolism and lipid metabolism related to energy transport and metabolism.Various GMCs had a specific relationship with the formation of H_(2)O_(2) during lignin and cellulose degradation.They could bind with flavin adenosine dinucleotide(FAD)to oxidize the primary alcohol group to form aldehyde and release H_(2)O_(2),providing a constant reaction substrate for peroxidases.Due to their important auxiliary role in the degradation of lignin and cellulose,GMCs are important auxiliary enzymes related to wood degradation.This study provides a basis for the functional study of GMC family in wood degradation of white rot fungi.