An Integrated Analysis of the Transcriptome and Proteome Reveals Host-Specific Cues in Cordyceps fumosorosea

Cordyceps fumosorosea (Wise) is a prominent entomopathogenic fungus with a broad host spectrum. The specificity of its infection mechanisms across different hosts, especially among lepidopteran species, remains largely enigmatic. This study employed RNA sequencing (RNA-Seq) and Tandem Mass Tag (TMT) proteomics to elucidate the differential pathogenic behavior exhibited by a particular C. fumosorosea isolate when confronting Plutella xylostella and Spodoptera litura. Our analyses revealed 3342 and 2416 differentially expressed genes (DEGs) and 332 and 296 differentially expressed proteins (DEPs) in C. fumosorosea cultured on the cuticles of P. xylostella (PI) and S. litura (SI), respectively. Notably, gene clusters and proteins associated with metabolism, cellular processes, and organismal systems were predominantly upregulated in the strain cultivated on PI compared to that cultivated on SI. In the PI group, significantly enriched metabolic pathways included fatty acid metabolism, nitrogen metabolism, and the metabolism of glycine, serine, threonine, and phenylalanine. Conversely, in the SI group, the upregulated proteins were significantly enriched in pathways related to phenylalanine metabolism, alanine, aspartate and glutamate metabolism, glycerophospholipid metabolism, and peroxisomal activities. These insights shed light on the reasons behind the distinct pathogenicity exhibited by a single C. fumosorosea against diverse hosts, offering prospects for the engineering of fungal strains with enhanced virulence.