Transcriptomic Analysis of Copper Resistance in Saccharomyces cerevisiae: Insights into Adaptive Evolution and Potential Implications for Wood Preservative Treatments

<b>Background/Objectives</b>: Copper-based wood preservatives are widely used to protect timber from fungal decay; however, the emergence of copper-tolerant fungi reduces their long-term effectiveness. This study aimed to elucidate the molecular mechanisms underlying copper resistance in <i>Saccharomyces cerevisiae</i> through adaptive evolution and transcriptomic profiling. <b>Methods</b>: A copper-resistant mutant was developed via stepwise exposure to CuSO₄·5H₂O, and its gene expression profile was compared to the wild-type strain under copper stress and non-stress conditions using Affymetrix GeneChip Yeast Genome 2.0 arrays. <b>Results</b>: Differential expression analysis revealed upregulation of key genes involved in copper transport (<i>ATX1</i> and <i>CTR1</i>), the oxidative stress response (<i>RCK1</i> and <i>SOD1</i>), and metal ion detoxification (<i>FRE3</i> and <i>SLF1</i>). Functional enrichment analysis highlighted the significant activation of pathways related to protein folding, mitochondrial function, and transcriptional regulation. <b>Conclusions</b>: These findings provide insights into the adaptive strategies employed by <i>S. cerevisiae</i> to tolerate copper stress and suggest potential gene targets for the development of more effective wood preservatives capable of mitigating fungal resistance.