Deep sequencing analysis of transcriptomes in Aspergillus oryzae in response to salinity stress

Characterization of the changes after various stimuli is crucial to comprehend the adaptation of cells to the changing condition. Aspergillus oryzae is widely used for the industrial production of soy sauce, which always encounter changes within a complex environment, such as salinity stress. However, the protective biochemical mechanisms of A. oryzae against salinity stress are poorly understood. In this study, we successfully characterized the fermentative behavior, transcriptomic profiles, and metabolite changes of A. oryzae in response to salinity stress. The results showed that salt treatment of A. oryzae inhibited the fungal development and conidia formation. Transcriptomic analysis showed an upregulated expression of the genes related to arginine accumulation and oleic acid synthesis. The results of qRT-PCR were further confirmed by the reliability and availability of the differentially expressed genes obtained from the transcriptome analysis. Metabolomic analysis revealed that the corresponding intracellular accumulation of arginine and oleic acid were also increased in response to the salinity stress. All of the results provide a global transcriptome characterization of the salt adaptation process in A. oryzae, and offer multiple target genes for salt tolerance improvement via genetic engineering.