Lytic Polysaccharide Monooxygenases as Chitin-Specific Virulence Factors in Crayfish Plague

The oomycete pathogen Aphanomyces astaci, also known as “crayfish plague”, is an obligate fungal-like parasite of freshwater crustaceans and considered responsible for the ongoing decline native European crayfish populations. A. astaci thought to secrete a wide array effectors enzymes that facilitate infection, however their molecular mechanisms have been poorly characterized. Here, we report identification AA15 lytic polysaccharide monooxygenases (LPMOs) new group secreted virulence factors in astaci. We show this enzyme family has greatly expanded compared all other oomycetes, it may infection through oxidative degradation crystalline chitin, most abundant found crustacean exoskeleton. These findings reveal roles LPMOs animal–pathogen interactions, could help inform future strategies protection farmed endangered species.