Cell wall reorganization during infection in fungal plant pathogens

• Fungal plant pathogens dynamically reorganize cell wall components during infection likely in response to plant factors.
• The cell wall surface of infectious hyphae was masked with α-1,3-glucan, a nondegradable polysaccharide for plants.
• The surface α-1,3-glucan allowed the fungi to evade host immunity via protection of the cell wall during infection.

The fungal cell wall, which is mainly composed of polysaccharides, is a major source of pathogen-associated molecular patterns (PAMPs). Because PAMPs recognition activates immunity in plants, successful pathogens have developed immune-evasion strategies. Studies of various fungal rice pathogens indicated that masking the cell wall surface with α-1,3-glucan, a polysaccharides that is not degradable by plants, is a fungal PTI evasion strategy. Interestingly, accumulation of α-1,3-glucan at the surface was specifically observed in presence of plants or plant factor(s). Since the surface α-1,3-glucan protected the fungal cell wall from digestive enzymes and interfered with PAMPs generation by host enzymes, fungal α-1,3-glucan is a potential target for plant protection strategies.