Omics Analysis Of Fruiting Body Development And Changes Of Antioxidant Activity In Flammulina Filiformis

As the main part of the development and utilization of edible and medicinal fungi,the development process of fruiting bodies has always been a hot spot of scientific research.The process of fruiting body growth and development of edible fungi is complex,involving the regulation of multiple genes and metabolic pathways.At present,there are few data on the mechanism of fruiting body growth and development at the overall level.China is the birthplace of artificial cultivation of Flammulina filiformis,and the germplasm resources are abundant.F.filiformis is delicious,rich in a variety of active substances,and antioxidant.The cultivation parameters of F.filiformis are stable and the genetic operation technology is mature,which can be used as a good material to study the growth and development regulation and antioxidant activity of edible fungi.In this study,based on the sequenced genome of F.filiformis,the transcriptome and proteome of different parts from fruiting body of F.filiformis at different stages of growth and development were analyzed,and the expression changes of genes and proteins during the development of fruiting bodies were analyzed as a whole.The transcription factors in the development of F.filiformis fruiting body were identified,and the expression pattern of transcription factor coding genes was clarified.At the same time,this study measured the content of active substances and antioxidant activity in different parts of F.filiformis fruiting bodies at different stages of growth and development,and revealed the changes of antioxidant activity during fruiting body development.Furthermore,combined with transcriptome and proteome data,the key genes in the regulation of active substance synthesis and antioxidant activity of F.filiformis were located.The main results of this study are as follows:1.Through the combined analysis of transcriptome and proteome,the gene and protein expression patterns during fruiting body development were revealed.Gene ontology(GO)functional clustering analysis showed that differentially expressed genes(DEGs)and differentially expressed proteins(DEPs)were mainly enriched in catalytic activity,binding,metabolic process,cellular component,cellular process and organelle entries.Kyoto encyclopedia of genes and genomes(KEGG)pathway enrichment analysis showed that most DEGs and DEPs were enriched in carbohydrate metabolism pathway,amino acid metabolism and amino acid biosynthesis pathway.In the mature pileus and stipe,many DEGs were enriched in nucleotide excision repair,base excision repair,mismatch repair,DNA replication and meiosis pathways.The genes of signal transduction pathways such as MAPK signaling pathway,two-component signaling system and Hippo signaling pathway were more active in the elongation pileus and primordium,maturation stipe and elongation stipe,maturation pileus and elongation pileus.More DEGs and DEPs were enriched in the drug metabolism-cytochrome P450 pathway and the metabolic pathway of cytochrome P450 to foreign organisms in the elongation pileus and primordium,maturation pileus and elongation pileus.Real-time quantitative PCR(RT-q PCR)analysis showed that the cytochrome P450 genes(gene227,gene1083)were related to the differentiation of fruiting bodies,and the cerato-platanin gene(gene2280)was highly expressed in the elongation stage of the pileus than the primordial stage,which was related to the pileus differentiation.2.The expression of transcription factor family genes in F.filiformis was different at different developmental stages and parts.Gene expression patterns showed a variety of clustering characteristics,and the expression patterns of most transcription factors in the same family were similar.The expression patterns of C2H2,Zn2Cys6,C3 H,b ZIP and MYB family transcription factors in primordium and stipe were similar.Most of the transcription factors of C2H2,Zn2Cys6,b ZIP,HB-other and MYB families were highly expressed in the pileus and lowly expressed in the stipe.Most transcription factors of C3 H family expressed higher in primordium and elongation stipe than in maturation stipe.The expression of most transcription factors of b HLH family in maturation pileus was lower than that in other periods.The expression of transcription factors in the same part of different periods was also different.The expression of Zn2Cys6 family transcription factors in the elongation stipe was lower than that in the maturation stipe,and the expression of C3 H and b ZIP family transcription factors in the elongation pileus was higher than that in the maturation pileus.3.The antioxidant activity of F.filiformis fruiting bodies at different developmental stages and different parts changed significantly.The polyphenol content in the elongation pileus was the highest,the ability to scavenge ABTS,DPPH and hydroxyl radicals was the strongest,and the reducing ability was strong.The polyphenol content in the primordium was the lowest,the ability to scavenge ABTS,DPPH and hydroxyl radicals was the weakest,and the reducing ability was the weakest.The polyphenol content was positively correlated with ABTS free radical scavenging rate,DPPH free radical scavenging rate and reducing power,and the correlation coefficients were 0.77,0.88 and 0.85,respectively.There was a significant negative correlation between polyphenol content and polysaccharide content,and the correlation coefficient was-0.73.The flavonoid content was significantly negatively correlated with ABTS free radical scavenging rate,DPPH free radical scavenging rate and reducing power,and the correlation coefficients were-0.71,-0.88 and-0.71,respectively.There was a significant positive correlation between flavonoid content and polysaccharide content,and the correlation coefficient was 0.80.There was a significant negative correlation between polysaccharides and DPPH free radical scavenging rate and reducing power,and the correlation coefficients were-0.82 and-0.72,respectively.Among the four antioxidant indexes,except for the negative correlation between hydroxyl radical scavenging rate and reducing ability,the other two were positively correlated.Among them,ABTS free radical scavenging rate was significantly positively correlated with DPPH free radical scavenging rate,and the correlation coefficient was 0.90.The DPPH radical scavenging rate was significantly positively correlated with the reducing ability,and the correlation coefficient was 0.82.Compared with other periods,the antioxidant capacity of the cap in the elongation period was stronger.Compared with polysaccharides and flavonoids,polyphenols play a major role in the antioxidation of F.filiformis.4.There was a significant correlation between the changes of antioxidant activity and the expression of key genes during the development of F.filiformis.In this study,some candidate genes and pathways related to active substances and antioxidant activity of F.filiformis were identified: polyphenol oxidase gene(gene8366),phenylalanine ammonia lyase gene(gene660,gene8260),superoxide dismutase gene(gene2800,gene10358),peroxidase gene(gene10260,gene11034)and catalase gene(gene9347,gene3932),ascorbic acid and alderate metabolic pathways.The activity of these pathways and key genes is closely related to antioxidant activity and the content of active substances.This study provides a theoretical reference for further revealing the global regulatory network of fruiting body development process of edible fungi,and the relationship between fruiting body development and antioxidant activity changes,and provides data support for fruiting body development mechanism and quality formation of edible fungi.