蜜环菌糖苷水解酶家族基因在菌索与菌丝间的差异表达分析

Analyses of the glycoside hydrolase family genes and their differential expressions between rhizomorphs and hypha in Armillaria mellea

蜜环菌是一种兼性腐生和寄生的真菌,通过降解伴栽基质并为药用植物(天麻)或菌物(猪苓)提供营养物质,而糖苷水解酶是这一过程的主要酶类。本研究从蜜环菌Armillaria mellea 541菌株转录数据库中共获得糖苷水解酶家族基因170个,分布于39个亚家族。进一步分析发现,这些家族基因编码的糖苷水解酶家族蛋白(glycoside hydrolase family,GHF)结构域多达48种181个,以Aamy、Glycohydro、MelibiaseC、Nod B homology和PA14等结构域为主。对糖苷水解酶家族蛋白进行了系统的Gene Ontology(GO)功能注释和Kyoto Encyclopedia of Genes and Genomes(KEGG)代谢通路分析,其功能以结合、水解和催化细胞壁成分为主。编码GHF3(A0A2H3D3T6)、GHF78(A0A2H3D8T6)、GHF51(A0A2H3E4X4)、GHF47(A0A2H3EK71)和GHF5(A0A2H3EBW7)等5个糖苷水解酶家族蛋白的基因在A. mellea541菌索与菌丝间差异表达,其结构域依次为PA14、Bacrhamnosid6H/C、Alpha-L-AFC、Glycohydro47和Glycohydro5,可能发挥结合碳水化合物和催化鼠李糖苷、阿拉伯呋喃糖苷、甘露糖残基和纤维素等水解的功能,这为研究蜜环菌与天麻或猪苓的相互作用提供了理论依据。

Armillaria sp. is a type of facultative saprophytic and parasitic fungus. It provides nutrients for medicinal plants(Gastrodia elata) or fungus(Polyporus umbellatus) by degrading the co-culture media and the glycoside hydrolase families(GHF) are the main enzymes in this process. In this study, 170 genes in 39 categories encoding GHF proteins were obtained from the transcription database of Armillaria mellea 541. Further analyses revealed that totally 181 domains of 48 classes were encoded by these GHF genes including Aamy, Glycohydro, MelibiaseC, NodB homology and PA14 domains, etc. GO function annotation and KEGG metabolic pathway analysis and enrichment were performed on GHFs systematically and their molecular functions included binding, hydrolyzing and catalyzing cell wall components. Five genes encoding GHF3(A0A2H3D3T6), GHF78(A0A2H3D8T6), GHF51(A0A2H3E4X4), GHF47(A0A2H3EK71) and GHF5(A0A2H3EBW7) expressed differently between rhizomorphs and hypha of A. mellea 541, containing PA14, Bacrhamnosid 6 H/C, Alpha-L-AFC, Glycohydro47 and Glycohydro5 domains successively, which may play roles in binding carbohydrates and catalyzing the hydrolysis of rhamnoside, arabinofuranoside, mannose residues and cellulose. This study provided a useful reference for uncovering the interactions between Armillaria sp. and Gastrodia elata or Polyporus umbellatus.