钾和锰对香菇菌丝体多糖含量及多糖合成关键酶的影响  

Study on the Effect of Potassium and Manganese on the Content of Mycelium Polysaccharide and Activities of Key Enzymes Related to Polysaccharide Biosynthesis of Lentinula edodes

作　　者：侯诗瑶 何茂兰 辜运富 陈强 向泉桔 HOU Shiyao;HE Maolan;GU Yunfu;CHEN Qiang;XIANG Quanju(College of Resources,Sichuan Agricultural University,Chengdu 611130,China)

机构地区：[1]四川农业大学资源学院,成都611130

出　　处：《四川农业大学学报》2024年第3期580-588,共9页Journal of Sichuan Agricultural University

基　　金：四川省应用基础研究项目(2022NSFSC0108);四川省科技计划项目(2021YFYZ0026);四川省食用菌创新团队项目(sccxtd-2024-07)。

摘　　要：【目的】探究K^(+)和Mn^(2+)对香菇菌丝体多糖含量、多糖合成关键酶酶活和多糖关键酶基因转录表达水平的影响。【方法】以主栽香菇品种新808为材料,设置5个不同金属浓度及4个不同的金属添加时间,分析K+和Mn^(2+)对香菇菌丝体生物量、胞内多糖(IPS)、胞外多糖(EPS)和总多糖(TPS)含量的影响,对3个多糖合成关键酶:葡糖磷酸异构酶(PGI)、葡萄糖磷酸变位酶(PGM)和尿苷二磷酸葡萄糖焦磷酸化酶(UGP)酶活及其编码基因转录表达水平的影响。【结果】以总多糖含量为指标,K+和Mn^(2+)的最佳诱导浓度分别为1000 mg/L和600 mg/L,最佳金属诱导时间均在接种后震荡培养7 d。动态分析结果显示,K+处理下,菌丝体多糖含量在整个培养期内较对照组低,培养前期PGI活性受到抑制,PGM和UGP活性升高,随着培养时间的延长PGM和UGP活性也受到抑制;Mn^(2+)处理下,培养60 d总多糖含量最高(55.42 mg/L),比对照高23.97%,在整个培养期PGM和UGP活性均较对照高。两种金属离子处理下,3个酶编码基因转录表达在培养前期均较高。相关性分析显示Mn^(2+)处理下EPS与TPS含量与PGM和UPG酶活显著相关(P<0.05)。【结论】发酵培养基中添加600 mg/L的Mn^(2+)能提高香菇菌丝体多糖产量,而1000 mg/L K+对香菇多糖合成具有抑制作用。【Objective】This study was conducted to explore the effects of potassium(K^(+))and manganese(Mn^(2+))on the mycelium polysaccharide productions,relative expression of key enzyme genes and en⁃zyme activities in polysaccharide synthesis.【Method】The effects of K^(+)and Mn^(2+)on mycelium growth,intracellular polysaccharide(IPS),extracellular polysaccharide(EPS),and total polysaccharide(TPS)productions were studied using the main cultivar Lentinula edodes′Xin808′.Five different metal concen⁃trations and four different metal adding times were employed in this study.The activities of three key en⁃zymes involved in polysaccharide biosynthesis,glucose phosphate isomerase(PGI),glucose phosphate mutase(PGM),and uridine diphosphate glucose focal phosphorylase(UGP),as well as the transcrip⁃tional expression levels of their coding genes,were also determined.【Result】When using the TPS con⁃tent as an indicator,the optimal induction concentrations of K^(+)and Mn^(2+)were 1000 mg/L and 600 mg/L,respectively,with the optimal induction time occurring after 7 days of shaking upon metal ions addition.Analysis on the dynamic changes showed that the polysaccharide contents were consistently lower under K^(+)treatments compared to the control throughout the incubation period.In the initial culture stage,the activity of PGI was inhibited while the activities of PGM and UGP were enhanced.However,in the later culture stage,the activities of PGM and UGP were also inhibited.The TPS content reached its maximum value when cultured for 60 d under Mn^(2+)treatment,coinciding with improved activities of PGM and UGP.Under K^(+)and Mn^(2+)treatments,all three genes showed relatively higher expression levels at early culture stage.Correlation coefficient analysis showed that the EPS and TPS contents significantly(P<0.05)corre⁃lated with enzyme activities of PGM and UPG under Mn^(2+)treatment.【Conclusion】Adding 600 mg/L of Mn^(2+)in the fermentation medium improves the yield of polysaccharide,while the addition of 1000

关 键 词：香菇 多糖 钾 锰 酶活 基因表达量 

分 类 号：S646[农业科学—蔬菜学]