The plant innate immune system employs plasma membrane-localized receptors that specifically perceive pathogen/microbe-associated molecular patterns (PAMPs/MAMPs). This induces a defence response called pattern-triggered immunity (PTI) to fend off pathogen attack. Commensal bacteria are also exposed to potential immune recognition and must employ strategies to evade and/or suppress PTI to successfully colonize the plant. During plant infection the flagellum has an ambiguous role, acting as both a virulence factor and also as a potent immunogen due to the recognition of its main building block, flagellin, by the plant pattern-recognition receptors (PRRs), including FLAGELLIN SENSING2 (FLS2). Therefore, strict control of flagella synthesis is especially important for plant-associated bacteria. Here we show that cyclic-di-GMP, a central regulator of bacterial lifestyle, is involved in the evasion of PTI.

 

(후략)