Effect of rapamycin on gene expression in Penicillium italicum

Citrus fruits are highly valued for their nutritional benefits and global economic significance. They are susceptible to many fungal pathogens during postharvest storage. Citrus blue mold caused by the fungus Penicillium italicum (P. italicum) is a major citrus disease, resulting in significant economic losses. However, the molecular mechanisms regulating the growth and development of P. italicum remain largely unexplored. The Target of rapamycin (TOR) is a central regulator of cell growth, metabolism, and stress responses in eukaryotes. In this study, we investigated the role of TOR in P. italicum using rapamycin, a specific TOR inhibitor. Transcriptomic analysis revealed that many genes related to membrane components, cell wall components and amino acids were deregulated after rapamycin treatment, indicating a potential role of P. italicum TOR (PiTOR) in regulating growth and metabolism. These results suggest that PiTOR functions in a conserved manner to control cell growth and metabolic processes. This study enhances our understanding of TOR signaling in phytopathogenic fungi and provides insights into potential strategies for controlling blue mold in citrus crops.