Total transcriptome response for tyrosol exposure in Aspergillus nidulans

Area of Science:

• Mycology
• Molecular Biology
• Biochemistry

Background:

• Tyrosol is recognized as a quorum-sensing molecule in Candida species.
• It exhibits antifungal properties at high concentrations.
• Understanding its effects on other fungi like Aspergillus nidulans is crucial.

Purpose of the Study:

• To investigate the physiological and transcriptional effects of tyrosol on Aspergillus nidulans.
• To elucidate the mechanisms behind tyrosol's antifungal activity.
• To identify affected metabolic pathways and cellular responses.

Main Methods:

• Treatment of Aspergillus nidulans with tyrosol at 35 mM.
• Analysis of conidial germination and growth on different carbon sources.
• Genome-wide transcriptional profiling using RNA sequencing.
• Measurement of glutathione-S-transferase (GST) activity and glutathione (GSH) content.

Main Results:

• Tyrosol significantly reduced conidial germination and growth, acting fungistatically.
• Downregulation of genes involved in cell cycle, glycolysis, and nutrient assimilation.
• Upregulation of genes related to lipid catabolism, amino acid degradation, and autophagy.
• Increased GST activity and GSH content, indicating a weak, GSH-dependent detoxification mechanism.
• No induction of oxidative stress, but upregulation of nutrient response and metabolic regulation genes.

Conclusions:

• Tyrosol impairs Aspergillus nidulans growth by disrupting metabolic regulation and nutrient utilization.
• The fungus attempts a weak GSH-dependent detoxification of tyrosol.
• Tyrosol's effects suggest a broad impact on cellular homeostasis and metabolic orchestration.