A calcofluor white hypersensitive protein Macwh1 contributes to cell wall integrity and pathogenicity in Metarhizium acridum

The fungal cell wall plays a vital role in fungal pathogenesis because it acts both as an environmental barrier and the major interface with the host immune system. Calcofluor white (CFW), a cell wall destroyer, binds to the neonatal chitin chain by hydrogen bonding and dipole interaction to prevent co-crystallization and microfiber formation. In this study, we invested a calcofluor white hypersensitive protein Macwh in entomopathogenic fungus, Metarhizium acridum. The results showed that the Macwh1 gene play important roles in the initial infection stage and cell wall integrity, while did not affect conidial germination and conidial yield. RNA-Seq analysis of the WT and Macwh mutant strains showed that many genes involved in cell wall construction and modification, secreted proteins and cell wall degradation enzymes, stress response and defense, and the pathogenicity related genes were downregulated in the Macwh mutant strains.