Beauveria bassiana through miRNA-mediated mitophagy affects Lymantria dispar cellular immunity

The entomopathogenic fungus Beauveria bassiana is widely used for biocontrol of destructive forest pests. However, the molecular mechanisms by which fungal infection disrupts host cellular homeostasis remain poorly understood. Here, we demonstrate that B. bassiana infection triggers mitophagy in Lymantria dispar hemocytes through reactive oxygen species (ROS) accumulation and miRNA-mediated regulation. Using transmission electron microscopy and gene expression profiling, we observed extensive mitochondrial damage and elevated expression of mitophagy-related genes (e.g., ATG13, BECN1) and lysosomal pathway components post-infection. Small RNA sequencing identified 93 differentially expressed miRNAs, with downregulated miRNAs (e.g., bmo-miR-2795, PC-3p-46410_42) targeting the PINK1-Parkin ubiquitination pathway. Functional enrichment analysis further linked these miRNAs to mitophagy activation. Our findings reveal a previously unrecognized strategy by which B. bassiana subverts host immunity via miRNA-regulated mitophagy, offering insights for optimizing fungal biocontrol agents.