GSE129372
Physiological and transcriptional response of Candida parapsilosis to exogenous tyrosol
Tyrosol plays a key role in fungal morphogenesis and biofilm development. Also, it has a remarkable antifungal effect at supraphysiological concentrations. However, the background of the antifungal effect remains unknown, especially in the case of non-albicans Candida species such as Candida parapsilosis We examined the effect of tyrosol on the growth, adhesion, redox homeostasis, virulence, as well as on fluconazole susceptibility. To gain further insights into the physiological consequences of tyrosol treatment we also determined the caused genome-wide gene expression changes using RNA-Seq. Fifteen mM tyrosol caused significant growth inhibition within two hours of the addition of tyrosol, while the adhesion of yeast cells was not affected. Tyrosol increased the production of reactive oxygen species remarkably as revealed by the dichlorofluorescein-test, and it was associated with elevated superoxide dismutase, glutathione peroxidase, and catalase activities. The interaction between fluconazole and tyrosol was antagonistic. Tyrosol exposure resulted in 261 and 181 differentially expressed genes with at least a 1.5-fold increase or decrease in expression, respectively, were selected for further study. Genes involved in ribosome biogenesis showed down-regulation, while genes related to oxidative stress response, and ethanol fermentation were up-regulated. In addition, tyrosol treatment up-regulated the expression of efflux pump genes including MDR1 and CDR1 and down-regulated the FAD2 and FAD3 virulence genes involved in desaturated fatty acid formation. Our data demonstrate that exogenous tyrosol significantly affects the physiology and gene expression of C. parapsilosis, which could contribute to the development of treatments targeting quorum-sensing in the future. Overall design: Examination of untreated control and 15 mM tyrosol-treated Candida parapsilosis cultures in three replicates.