Preliminary Study On The Mechanism Of Mycelial Maturation Of Pleurotus Ostreatus Induced By Low Temperature

Pleurotus ostreatus,also known as Pleurotus ostreatus,is the main edible fungus variety in my country.Pleurotus ostreatus is a typical temperature-changing edible fungus.The mycelium must undergo low temperature induction treatment to mature,and then differentiate into primordium to form fruit bodies.Therefore,temperature is one of the important factors affecting the maturation of Pleurotus ostreatus.At present,there are few researches on the maturation mechanism of Pleurotus ostreatus hyphae induced by low temperature.In this study,the Pleurotus ostreatus strain "Shuangkangheiping" was used as the material,and three different temperature treatment hyphae were set up,25 ℃(control group),17 ℃(low temperature treatment group),33 ℃(high temperature treatment group),explore the changes of physiological indicators of mycelium and the growth and development of fruit bodies under different temperature induction treatments,And collect the hyphae of different temperature treatment groups,conduct transcriptome analysis,reveal the mechanism of low temperature-induced Pleurotus ostreatus hyphae maturation.The research results are as follows:1.After different temperature treatments,neither the control group nor the 33 ℃high-temperature treatment group had primordium formation,so fruit bodies could not be formed;the 17 ℃ low-temperature treatment group had primordium formation and could produce normal mushrooms.2.Temperature has an important effect on the physiological indicators of Pleurotus ostreatus mycelium.After 17 ℃ low temperature treatment and 33 ℃ high temperature induction treatment,DAB staining showed that the hyphae in the treatment group were stained deeper;the soluble sugar,soluble protein,and soluble protein in the treatment group The content of free proline was significantly higher than that of the control group(P<0.05),and the content of each substance in the 33 ℃high temperature treatment group was the highest;the trend of changes in malondialdehyde and relative conductivity was basically the same,and both were significantly higher than in the treatment group Control group(P<0.05);the order of CAT activity in mycelium is 33 ℃ treatment group>17 ℃ treatment group>25 ℃treatment group;the high temperature treatment group has the highest POD activity of hyphae,reaching 115.63 U·g-1·min-1,but there was no significant difference between the 17 ℃ treatment group and the control group(P>0.05);after 7 days of induction treatment at different temperatures,the SOD activity in the control group was the highest,but after 12 h and 24 h treatment,the treatment group was significantly higher than the control Group.3.Analysis of mycelial transcriptome data found that compared with the control group,711 differentially expressed genes were identified in the 17 ℃ treatment group,of which 298 were up-regulated and 413 were down-regulated.Go functional enrichment analysis showed that 141 genes were up-regulated and 81 genes were down regulated,which were mainly involved in heme binding,Tetrapyrrole binding,Oxidoreductase activity,Iron ion binding,Oxidoreductase activity,acting on paired donors,incorporation or reduction of molecular oxygen,etc.focus on molecular function.Enrichment of KEGG pathway shows that up-regulated genes at 17 ℃ are mainly involved in nitrogen metabolism,unsaturated fatty acid biosynthesis,and steroid biosynthesis(P-Value<0.05),and down-regulated genes are mainly involved in cysteine and methionine metabolism,and tyrosine metabolism,Glycosphingolipid biosynthesis-globulin series,oxidative phosphorylation,aflatoxin biosynthesis,propionic acid metabolism,glycosaminoglycan degradation,fatty acid biosynthesis(P-Value<0.05).4.The hyphal transcriptome data were analyzed.Compared with the control group,1715 differentially expressed genes were identified in the 33 ℃ treatment group,including 1012 up-regulated genes and 703 down regulated genes,with a total of 386 differentially expressed genes.Go functional enrichment analysis showed that among the differential genes,312 genes were up-regulated and 357 genes were down regulated,which were mainly involved in heme binding,tetrapyrrole binding,cell wall structural components,redox enzyme activity,fungal cell wall,cell wall and redox enzyme activity,acting on paired donors,incorporation or reduction of molecular oxygen,iron ion binding,redox process Outer packaging structure,etc.Enrichment of KEGG pathway shows that up-regulated genes are mainly involved in tryptophan metabolism,arginine and proline metabolism,phenylalanine metabolism,biotin metabolism,methane metabolism,β-alanine metabolism,etc.down-regulated genes are mainly involved Oxidative phosphorylation,citric acid cycle,tyrosine metabolism,glycolysis/gluconeogenesis,cysteine and methionine metabolism,etc.In this study,the Pleurotus ostreatus strain "Shuang kang hei ping" was used as the test material to determine the fruiting condition,active oxygen,osmotic adjustment substances,superoxide dismutase,peroxidase,Changes in physiological indicators such as catalase and malondialdehyde.The hyphae transcriptome analysis was carried out,and the physiological and molecular mechanisms of hyphae maturation were initially explored,which provided theoretical basis and technical support for further understanding of the growth process and actual cultivation and production of Pleurotus ostreatus hyphae.