灵芝转录因子AreA的生物学功能  

Biological function of the transcription factor AreA in Ganoderma lingzhi

作　　者：朱静 宋书琪 岳思宁 连玲丹 赵明文[1] ZHU Jing;SONG Shu-Qi;YUE Si-Ning;LIAN Ling-Dan;ZHAO Ming-Wen(College of Life Sciences,Nanjing Agricultural University,Key Laboratory of Edible Mushroom Processing,Ministry of Agriculture and Rural Affairs,Nanjing,Jiangsu 210095,China)

机构地区：[1]南京农业大学生命科学学院农业农村部食用菌加工重点实验室

出　　处：《菌物学报》2020年第1期57-65,共9页Mycosystema

基　　金：中国博士后基金（2017M611835）;江苏省自然科学基金(BK20180535)~~

摘　　要：AreA作为丝状真菌氮代谢中的关键转录因子,在真菌响应外界氮源、生长发育、次级代谢及抗逆过程中发挥了重要作用。本研究通过生物信息学比对分析,获得了灵芝AreA的全长序列,研究了AreA对菌丝生长、抵御细胞壁胁迫以及次级代谢的影响,AreA编码蛋白的C末端含有保守的GATA型锌指结构域,与其他担子菌中AreA的亲缘关系较近。通过qRT-PCR分析发现,外界氮源浓度的变化能够影响AreA的转录水平。在低氮源浓度条件下,AreA的转录水平显著高于氮源丰富的条件。利用前期构建的AreA沉默转化子研究发现,沉默AreA后菌株生长速率显著低于野生菌株,约下降70%;且AreA沉默菌株菌丝比野生菌株蓬松。细胞壁的组成成分检测发现,AreA沉默菌株的葡聚糖和几丁质含量比野生菌株(WT)和转入空载沉默质粒的菌株(CK)分别下降约65%和40%–60%。随后检测了对细胞壁胁迫的耐受性,结果发现AreA沉默转化子对刚果红和SDS极为敏感,几乎不能生长。在AreA沉默菌株中,灵芝三萜的含量相比于对照菌株下降了约23%。研究结果表明灵芝AreA能够响应环境中的氮源浓度,并且在灵芝的生长发育、次级代谢以及抵御细胞壁胁迫中发挥了重要作用。As a key transcription factor in fungal nitrogen metabolism, Are A functions in growth, secondary metabolism and stress resistance. In this study, the full-length sequence of Are A was obtained by bioinformatics comparison analysis, and the influence of AreA on growth, resistance to cell wall stress and secondary metabolism were studied. The C terminal domain of AreA contained a conserved zinc finger domain. qRT-PCR analysis indicated that Are A could response to different nitrogen sources. Are A transcription level increased under low nitrogen concentration condition as compared with that under high nitrogen concentration condition. The growth rate of Are A silenced strains was significantly lower(decreased by 70%) than that of the control strains. It was found that the hyphae of Are A silenced strains were fluffier than those of the control strains. Detection of the composition of cell wall indicated that the content of β-glucan and chitin decreased by 65% and 40%–60%, respectively as compared with wild type(WT) and CK strains. The tolerance to cell wall stress was examined and the results showed that Are A silenced strains were sensitive to Congo red and SDS, and the growth stagnated on the plates. The content of ganoderic acid in Are A silenced strains decreased by 23% as compared with that in the control strains. Our study indicated that Are A as a transcription factor could response to the nitrogen source and play important role in growth, secondary metabolism and resistance to the cell wall stress in G. lingzhi.

关 键 词：转录因子AreA 氮源 生长 细胞壁胁迫 次级代谢 

分 类 号：S567.31[农业科学—中草药栽培]