Transcriptome Analysis of Ophiocordyceps Sinensis Under Low-Temperature Treatment

Abstract This study aims to investigate the effect of low temperature on the gene expression in Ophiocordyceps Sinensis. To set up the experiments, two groups of Ophiocordyceps Sinensis were grown at 4°C and 18°C, respectively, for 60 days. Differential gene expression was analyzed by transcriptome sequencing and the morphology of mycelium was studied under scanning electron microscope for the two groups. The results showed that there were significant differences in hypha morphology between the two groups. Transcriptome analysis indicated that 2799 genes were differentially expressed in the low-temperature treatment group compared to the normal temperature group. Among these genes, 1489 were up-regulated, whereas 1310 were down-regulated. Further analysis revealed that 33 genes were only expressed at low temperature compared to 26 genes which were only expressed at normal temperature. GO enrichment analysis showed that the 33 genes were related to redox enzymes, which have functions in clearing reactive oxygen species and free radicals caused by low-temperature environment. KEGG enrichment analysis showed that the 33 genes were mainly involved in the cyanoamino acid metabolism, biosynthesis of amino acids, carbon metabolism, pantothenate and CoA biosynthesis, biotin metabolism, phenylpropanoid biosynthesis, apoptosis and other metabolic pathways. Our observations provide fundamental clues on the relationship between the low-temperature stimulation and the fruiting body development and further promote the research progress on Ophiocordyceps Sinensis.