The global gene expression profile of the model fungus Saccharomyces cerevisiae induced by thymol.

Aim: To determine the transcriptional responses of model fungus Saccharomyces cerevisiae (S. cerevisiae) cells upon exposure to thymol (THY). Methods and Results: Commercial oligonucleotide microarrays and quantitative real-time RT-PCR were used to study the transcriptional responses of S. cerevisiae to THY. Compared with the transcriptional profiles of untreated cultures, 305 genes were significantly upregulated, and 212 genes were significantly downregulated in THY-treated cells. We interpreted the microarray data using a hierarchical clustering tool, T-profiler. Glucose-dependent efflux of rhodamine 6G (R6G) from S. cerevisiae was performed to assay a phenotypic correlation between ATP-binding cassette transporter overexpression induced by THY and efflux of R6G. The addition of THY resulted in an increase in the concentration of released fluorescence, following the addition of glucose. Additional phenotype analysis showed that the intracellular concentration of thiamine was decreased by THY, and THY led to lesions in the membranes; these were consistent with the results of microarray. Conclusion: The transcriptional response of S. cerevisiae to THY was determined, and several changes in genetic regulation were verified in physiological effects on the cell. Significance and Impact of the Study: Taken a whole-genome view to elucidate the mechanism of THY as a potential antifungal agent.