Transcriptional Analysis Reveals the Iron Regulation Network of the Pathogenic Yeast Metschnikowia bicuspidata in Response to Iron Stress

Metschnikowia bicuspidata, a globally distributed opportunistic pathogenic fungus, poses a significant threat to crustaceans in diverse aquatic ecosystems, causing severe diseases. Iron, recognized as a virulence factor, plays a crucial role in successful infection with M. bicuspidata. Therefore, this study aims to investigate the transcriptome response of M. bicuspidata to low- and high-iron conditions. Overall, 1082 differentially expressed genes (DEGs) (FDR < 0.05, |log2FC ≥ 1.5|) were identified, comprising 977 and 105 DEGs, in response to low- and high-iron conditions, respectively. These genes predominantly participate in altering metabolism, cell membranes, or cellular structure, allowing the organism to adapt to varying iron levels. Iron limitation-induced genes play crucial roles in energy metabolism, transport, and catabolism pathways. Moreover, 27 ortholog genes were associated with iron transport and homeostasis, with 7 of them participating in iron uptake and regulation under low-iron conditions. This study contributes to the comprehension of iron homeostasis in aquatic fungi. It may offer potential therapeutic strategies for managing M. bicuspidata diseases.