Studies Of Liquid Strain And Nutrient Utilization In Different Growth Stages And Transcriptome Analysis On Hericium Coralloides

Hericium coralloides,a kind of rare and precious medicinal fungi in China with beautiful appearance and high nutritional and medical value.In recent years,the production range of H.coralloides has gradually spread from the northeast to the south in China.With the development strategy of‘Going Global’,it has been successfully introduced to Zambia and integrated the tropical plateau industrialization technology.However,the basic research of H.coralloides was backward,solid mother spawn production methods was not efficient as we thought,rules of nutrient utilization were not clear,and the problems of group research were all affecting the sustainable development of H.coralloides industry.Therefore,based on the research defined the sexual reproductive system and morphological development rules and established the method for the solid mother spawn production.Liquid culture,nutrient utilization,polysaccharide research and transcriptome sequencing analysis were carry out in different growth stages using the provincial variety‘Jade coral’as the test culture and solid culture as control,in order to find nutrient utilization regulation of different carbon-nitrogen-to-liquid cultures and analysis the differential expression of genes related to nutrient utilization and polysaccharide synthesis during the growth and development process aiming at laying a foundation for the efficient development and mechanism of nutrient utilization regulation of H.coralloides,and promoting the scientific development of H.coralloides industry.Main findings are as follows:1.Carbon and nitrogen sources of liquid culture medium of H.coralloides were treated by single factor.The optimum carbon source and nitrogen source of liquid culture was corn and yeast extract powder.By adjusting the carbon source content to prepare six medium formulations with different C/N ratios,and investigating the quality of culture（mycelial diameter,density,biomass）.and the optimum formula was K2 and C/N ratio was11:1,corn 15g/L,and glucose 5g/L.Yeast extract 5g/L,potato 200g/L,wheat bran 2g/L,magnesium sulfate 1.5g/L,potassium hydrogen phosphate 3g/L,VB1 0.01g/L.The optimum culture conditions were A₅B₄C₃D₅E₃,which was 3.5%of inoculation volume,150 mL（250 mL triangular bottle）,inoculation age 7d,rotation speed180r/min,pH 5.0,mycelial biomass 1.1467 g/250 mL,ball.The average diameter was 2.019 mm and the density was 140/25mL.The liquid culture was prepared with the best liquid formula and the culture conditions.The industrial cultivation experiment was carried out with the solid strain as the control.The agronomic traits were investigated.The growth period was shorter by 3 days than control group.The fresh weight yield of dry material per 500 g was increased by 26.22%and the fresh weight was 35.35%.3.At the same time,the polysaccharide content of liquid cultured mycelia and fruiting bodies was extracted by hot water extraction method.The content of polysaccharide was determined by phenol sulfuric acid method.The difference of polysaccharide content between mycelia and fruiting bodies was compared.The results showed that the extraction rate of mycelial polysaccharides and fruiting body polysaccharides was 2.27%and 6.15%when the liquid fermentation medium was K5（carbon-nitrogen ratio was 14:1,corn 45g,glucose 10g,yeast extract 5g,potato 200g,wheat bran 2g,magnesium sulfate 1.5g,potassium dihydrogen phosphate3G and VB10.01g）.The optimum cultivated conditions were:2.5%or 3.5%inoculation,120 mL（250 mL triangular bottle）,7 days inoculation age,160 r/min rotation speed,4.5 pH value.Polysaccharide extraction rate was 3.74%.4.The results showed that there were significant differences in nutrient utilization rate and polysaccharide content of H.coralloide.Total RNA was extracted from the mycelium,primordium and fruiting body,then sequenced by high-throughput sequencing The differentially expressed genes were analyzed.GO,KEGG function annotation and fluorescence quantitative PCR were used to verify the results.The results showed that:（1）clean reads were 368,677,078,94,486 Trinity transcripts and 44,156 genes were obtained.（2）15192,9939 and 15460 genes were differentially expressed in mycelia,primordia and fruiting bodies.（3）Differentially expressed genes were annotated by GO function to 48 functional groups;differentially expressed genes were annotated by KEGG to 13 metabolic pathways.（4）It was proved that GH family genes related to nutrition utilization were positively correlated with lignocellulase activity,and genes related to polysaccharide synthesis were positively correlated with polysaccharide changes at different growth stages.The situation was positively correlated with the yield of polysaccharides.