Differential gene expression and associated metabolite accumulation in fungus Ophiocordyceps xuefengensis cultivated under breathable and airtight conditions.

Ophiocordyceps xuefengensis is a kind of caterpillar fungus and used as ethnopharmacological invigorant in China. A transcriptomic approach was applied to reveal the differential gene expression of O. xuefengensis under breathable and airtight conditions, and the targeted metabolites were determined by HPLC-QTOF-MS/MS technology. Growth was inhibited during 28 d cultivation and a total of 170 differentially expressed genes were obtained under airtight condition. The differentially expressed genes were mainly significantly enriched into amino acid metabolic pathways, namely tryptophan metabolism, phenylalanine metabolism, arginine and proline metabolism. These significantly enriched metabolic pathways were all involved in the enzyme amidase. Meanwhile, the content of tryptophan, phenylalanine, arginine and proline were increased under airtight condition. Consequently, the metabolism of these amino acids was supposed to be suppressed in O. xuefengensis under airtight condition. The detailed knowledge of this transcriptional program and biochemical analysis will allow for a systematic understanding of cordyceps fungus cultivation. • Growth of O. xuefengensis was inhibited in airtight condition. • Genes relating to amidase were down-regulated in airtight stress. • DEG-associated amino acids were accumulated in airtight stress. [ABSTRACT FROM AUTHOR]