Fungal effectors

[1][2][3] In the first stages of infection, conserved molecules from the fungal pathogen's cell wall, such as polysaccharides and chitin, are recognised by membrane-localised pattern recognition receptors (PRRs) on the plant host's side.

Such conserved molecules are generally described as pathogen-associated molecular patterns (PAMPs) or microbe-associated molecular patterns (MAMPs) and the initial innate immune response that their recognition triggers is known as PAMP-triggered immunity (PTI).

[4] In order to counteract PTI, fungal pathogens secrete effector proteins into the host, some of which may directly inhibit components of the innate immune response cascade.

[8] Avr4 - binds to chitin oligomers in the fungal cell wall, protecting it from degradation by chitinases.

[10] Avr-Pizt - interacts with the E3 ubiquitin ligase APIP6, which indirectly leads to reduced Reactive Oxygen Species (ROS) production and suppresses the expression of defence-related genes.