Fungal Spoilage in Postharvest Horticultural Products: Molecular Perspectives and Sustainable Control Strategies

Postharvest fungal pathogens are the primary cause of spoilage in fruits and vegetables, leading to substantial economic losses and posing persistent threats to global food security. Necrotrophic fungi such as Botrytis and Penicillium , together with hemibiotrophic pathogens like Colletotrichum , deploy sophisticated infection strategies that exploit the postharvest environment. This review synthesizes current understanding of the molecular mechanisms underlying these infections, from initial adhesion and penetration through wounds or natural openings, to the secretion of cell wall-degrading enzymes and phytotoxic secondary metabolites that disable host defenses and drive tissue necrosis. We examine how pathogens manipulate host-derived reactive oxygen species, converting a defensive oxidative burst into a trigger for programmed cell death that facilitates their necrotrophic lifestyle. The phenomenon of quiescent infections, in which fungi remain dormant until host ripening or senescence signals reactivate necrotrophic colonization, is also explored. Finally, we discuss how these mechanistic insights guide the development of molecular-based control strategies that target specific virulence pathways, offering sustainable alternatives to conventional fungicides for reducing postharvest losses and securing a safe food supply.