Differential expression analysis of the transcriptome at different cycles of harvesting periods of Agaricus bisporus

【Objective】The transcriptome differential expression of Agaricum bisporus at different cycles of harvesting periods was analyzed to provide theoretical reference for screening key genes affecting yield and quality of A. bisporus and efficient cultivation of A. bisporus. 【Method】Using A. bisporus A15 as experimental material, transcriptome sequencing（RNA-Seq）technology was used to analyze the samples of A. bisporus A15 at the first cycle of harvesting period（CZ1）, the second cycle of harvesting period（CZ2）and the third cycle of harvesting period（CZ3）. RNA-Seq data sequences were compared with reference genomes to screen for differentially expressed genes. GO functional annotation and KEGG signaling pathway enrichment analysis were performed for differentially expressed genes. The accuracy of RNASeq results was verified by real-time fluorescence quantitative PCR. 【Result】A total of 58.54 Gb Clean data was obtained from samples of different cycles,with Q20 ranging from 98.41% to 98.49%,Q30 ranging from 95.01% to 95.24%,and effective base proportion ranging from 49.00% to 49.70%. Taking CZ1 sample as the control group, 849 and 1297 differentially expressed genes were screened in CZ2 and CZ3 samples respectively. A total of 545 differentially expressed genes were detected in CZ1 vs CZ2 group and CZ1 vs CZ3 group. There were 90 differentially expressed genes in CZ1 vs CZ2 group, CZ1 vs CZ3 group and CZ2 vs CZ3 group. The GO function annotation analysis of differentially expressed genes showed that the GO function of differentially expressed genes in CZ1 vs CZ2 group and CZ1 vs CZ3 group could be divided into 3 categories:biological process, molecular function and cell component. KEGG signaling pathway analysis showed that metabolic pathways, antibiotic biosynthesis and secondary metabolites synthesis were significantly enriched in CZ1 vs CZ2 group and CZ1 vs CZ3 group. Ten differentially expressed genes with high expression were selected from the differentially expressed genes for analysis. The expression level of tyrosinase gene（TYR） in CZ3 sample was as 7.04 times as that of CZ1 sample, and the expression level of catalase gene（CAT3）in CZ1 reached the peak, and was as 3.20 times as that in CZ3. The expression trend of 4 differentially expressed genes was basically consistent with the results of RNA-Seq analysis. 【Conclusion】Ten genes with high expression were selected from the samples of A. bisporus A15 in 3 different cycles of harvesting periods, including TYR, a key rate-limiting enzyme gene that catalyzed melanin production, and CAT3, a catalase encoding gene. The antioxidant capacity of A. bisporus is different at different cycles of harvesting periods. The antioxidant capacity of A. bisporus at the first cycle of harvesting period is the strongest, while the antioxidant capacity at the third cycle of harvesting period is the weakest.