Analysis Of Differences Of Gene Expression Profiles For Stipes Of Postharvest Volvariella Volvacea

Fruiting bodies of postharvest Volvariella volvacea are hard to storage.However, the study of its gene expression is little.In this study, gene expressing changes of stipe in postharvest fruiting bodies of V. volvacea were researched. The fruiting bodies of V. volvacea at egg-shaped period were harvested. Their stipes of postharvest 0 h,1.5h,stretch period,maturity period were obtained and storaged in the liquid nitrogen. The total RNA form these stipes of four different periods were extracted, their mRNA were purified and counter-duplication synthesised double strand cDNA.The cDNA was sequenced using digital gene expression system. Digital gene expression profiles of stipes of V. volvacea in the different storage period were appraised. The saturation of sequencing, distribution of clean tag copy number, alignment statistics of the clean tags were analyzed. Differentially expressed genes were screened and classificated. Gene ontology functional enrichment results, pathway enrichment results and clustering results of differentially expressed genes were analyzed. The significant differences genes, genes of coding enzymes and genes of controling amino acids synthesis were analyzed emphatically. These results were the theory basis for the research of oxidation resistance, anti-senile and suppress fruiting body opening for V.volvacea.3783 genes expressed differently between postharvest 1.5 hours and the postharvest 0h stipes of V. volvacea, which included 729 up-regulated genes and 3054 down-regulated genes. 4959 genes expressed differently between postharvest stretch period and the postharvest 0h stipe of V. volvacea, which included 1257 up-regulated genes and 3684 down-regulated genes. 4650 genes expressed differently between postharvest maturity period and the postharvest 0h stipe of V. volvacea, which included 1448 up-regulated genes and 3202 down-regulated genes.Gene ontology functional enrichment analysis for differentially expressed genes beween postharvest 1.5 hours and the postharvest 0h stipe of V.volvacea showed that significant enrichment GO terms were ribonucleoprotein complex,macromolecular complex,structural molecule activity,gene expression. Pathway enrichment analysis for the differentially expressed genes showed that significant enrichment pathway were ribosome,DNA replication,cell cycle,sphingolipid metabolism,pathways in cancer,mismatch repair,glyoxylate and dicarboxylate metabolism,alanine,aspartate and glutamate metabolism,colorectal cancer,antigen processing and presentation,fatty acid biosynthesis.Gene ontology functional enrichment analysis for differentially expressed genes between pstharvest stretch period and the postharvest 0h stipe of V. volvacea showed that significant enrichment GO terms were macromolecular complex,ribonucleoprotein complex,structural molecule activity. Pathway enrichment analysis for the differentially expressed genes showed that significant enrichment pathway was ribosome.Gene ontology functional enrichment analysis for differentially expressed genes between postharvest maturity period and the postharvest 0h stipe of V. volvacea showed that they were not significant enrichment GO term. Pathway enrichment analysis for the differentially expressed genes showed that significant enrichment pathway was fatty acid metabolism.Some characteristic genes of postharvest 1.5 h and maturity period were found by clustering analysis of DGEs. From significant differences genes analysis, we found the following:1. Compared with Postharvest 0h, postharvest 1.5h synthetic amino acid quantity and type may reduce, especially affect some essential amino acids.2. The stipe growth of V. volvacea was related to endoglucanase-4.3. In the gene expression profile of stipe of postharvest 1.5h, high expression amount of deuterolysin M35 metalloprotease showed that it is the important factors of protein degradation in the storage.4. High expression amount of cellulose-growth-specific protein of postharvest stretch period promote the stipe elongation and membrane rupture of V. volvacea.5. High expression amount of chitin deacetylase showed that stipes of postharvest stretch period have autolysised.6. High expression amount of glutathione S-transferase and lectin PVL against adversity in the postharvest maturity period.7. High expression amount of aldehyde dehydrogenase showed that ethanol metabolic and the toxic substances increase in the postharvest maturity period. From enzymes living changes, the following was found:1.The largest expression amount gene of coding superoxide dismutase coded manganese superoxide dismutase. And in the storage, its expression amount sharply increase. We can speculate that manganese superoxide dismutase (sod) resistance to oxidation of stipe in the storage.2. In the storage, putative versatile peroxidase precursor and thioredoxin-dependent peroxidase were up-regulated ,we can speculate that they have anti-ageing effect.3.In the postharvest process, catalase first increase but then reduce,which explained that catalase up-regulated to resist oxidation in the postharvest stretch period and maturity period.4.In the storage period, the expression amount of metalloprotease and ATP-dependent protease La are high, which showed that the two kinds of protease influence stipe quality of V. volvacea greatly. we can reduce the two protease gene expression to prolong storage period of V.volvacea.From the analysis of amino acid metabolism, we can speculate that synthesis volume of L– valine,L– isoleucine,L-methionine,L– lysine,L– threonine and L– leucine have reduced greatly in the stipe of postharvest 1.5h.