Regulatory Role of PhiA in Penicillium expansum Sporogenesis and Stress Response

WANG Yanling; CHEN Xin

doi:10.13982/j.mfst.1673-9078.2026.1.1434

Abstract：The cell wall protein PhiA is implicated in conidiogenesis in filamentous fungi and is closely associated with the development and formation of conidiophores.To preliminarily analyze the role of PePhiA in Penicillium expansum,PephiA was cloned and its cellular location was identified.Homologous recombination was then used to create ΔphiA,a PephiA gene deletion mutant,to explore the function of PePhiA in P.expansum.The results demonstrated that PePhiA encodes a protein of 182 amino acids with a signal peptide located in the cell wall,which is predominantly distributed in the mycelial membrane,conidiophore,and spores.The colony morphology of the mutant ΔphiA was green and circular with smooth edges,almost identical to that of the wild-type.Although the colony diameter and spore production were unaffected,the spore germination rate and bud tube length decreased by 22.73%and 13.26%,respectively,at 12 h.The pathogenicity and patulin yield of the mutant ΔphiA were not significantly different from those of the wild-type.Additionally,PephiA responded to both cell wall stress and osmotic stress,and its sensitivity to KCl,NaCl,CR,and SDS increased in sequence,resulting in increased inhibition of 14.47%,11.89%,11.36%,and 6.70%,respectively.These results suggest that PhiA is involved in the regulation of spore and mycelium formation in P.expansum and that PephiA is essential for maintaining cell wall integrity and responding to osmotic stress.This study provides a theoretical foundation for understanding the genetic network of asexual development associated with the biocontrol potential of P.expansum.