Deciphering Neutral Ceramidase-Dependent Mechanism of Response to Aromatic Fungicides Stress in Neurospora crassa

Ceramidases hydrolyze ceramides to fatty acids and sphingolipids, but their role in fungal response to stress remains unclear. We investigated the function of neutral ceramidase (nCDase) response to aromatic fungicide (carvacrol, cuminaldehyde, and isoniazid) stress in Neurospora crassa. Comparative analysis of the wild-type strain, Δnc and OEnc showed that nCDase enhanced fungicide resistance through multiple mechanisms. nCDase improved β-1,3-glucan synthesis (30% increase), decreased membrane permeability, elevated superoxide dismutase and catalase activities, and promoted carotenoid accumulation (50%), which collectively improved stress tolerance. Δnc exhibited disruption of cellular integrity, altered fatty acid profiles (elevated oleic acid, reduced total fatty acids), and increased fungicide sensitivity. Collectively, these findings established that nCDase as a key regulator of cell wall dynamics, lipid homeostasis, and antioxidant defense, thereby facilitating fungal adaptation to abiotic stress. This study identified the role of nCDase in the response to aromatic fungicide stress and laid foundation for inhibiting pathogenic fungi in agricultural production and food preservation.