利用转录组分析光照对香菇菌丝生长的影响

Transcriptome Analysis of Mycelial Growth of Lentinula edodes Under

分别在光照(每天照射200~300 lx白光12 h)与黑暗(对照)环境中培养香菇(Lentinula edodes)菌丝,菌袋培养14 d后观测菌丝表型,并利用转录组分析光照对香菇菌丝生长的影响。结果表明:与黑暗组相比,光照组的菌丝更加浓密洁白;共有112个差异基因上调表达,99个差异基因下调表达。GO功能富集分析表明:差异基因在生物过程中显著富集于多糖分解过程、霉菌毒素代谢过程、真菌毒素生物合成过程等条目,在细胞组成中显著富集于细胞外区域、外部封装结构、细胞壁等条目,在分子功能中显著富集于细胞壁的结构成分、纤维素结合域和过氧化物酶活性等条目。KEGG代谢途径富集分析表明,差异基因富集的通路包括MAPK信号通路、甘油磷脂代谢、组氨酸代谢等。筛选出与菌丝生长相关的14个重要差异表达基因,并对随机选取的7个差异表达基因进行qRT-PCR验证,结果表明差异表达基因的表达模式与转录组分析结果一致。与黑暗组相比,光照组的菌丝漆酶活性更高。光照影响香菇菌丝生长机制模型可能是:香菇菌丝感应到光信号并通过MAPK通路的信号转导途径调控下游转运蛋白表达,进而调控木质素降解酶基因的表达及活性,从而加快菌丝营养物质积累,促进香菇菌丝营养生长。

Mycelia of Lentinula edodes were cultured under light illumination(200–300 Lx white light 12 h·d-1)and in the dark(control)for 14 d,respectively.Then mycelial phenotype was observed,and transcriptome data were analyzed.The results showed that mycelia cultivated under light appeared denser and whiter than those in the dark group.There were 112 up-regulated and 99 down-regulated differentially expressed genes between the two groups of different light conditions.GO functional enrichment analysis indicated that the differentially expressed genes were enriched in biological processes of polysaccharide decomposition,mycotoxin metabolism,and mycotoxin biosynthesis,in cell components of extracellular region,external encapsulation structure and cell wall,and in molecular functions of cell wall structural constituent,cellulose binding and peroxidase activity.KEGG pathway enrichment analysis showed that the differentially expressed genes were mainly involved in MAPK signaling pathways,glycerophospholipid metabolism,histidine metabolism.Fourteen important differentially expressed genes related to mycelial growth were identified,and five of them were then verified by qRT-PCR.Compared with the dark group,the light group showed a higher laccase activity in mycelia.It appeared that light signal may regulate the expression of downstream transporters of a MAPK signaling cascade,and then regulate the expression and activity of lignin-degrading enzymes,thereby improving the accumulation of nutrients in mycelia and vegetative growth of L.edodes.