A glutathione peroxidase (GpoA) plays a role in the pathogenicity of Nautella italica strain R11 towards the red alga Delisea pulchra

Abstract

Oxidative bursts are a common mechanism used by higher organisms to defend themselves against bacterial attacks, but some pathogenic bacteria have evolved resistance mechanisms to counteract this. The role of oxidative stress resistance as a virulence trait in macroalgal disease is however unknown. Here, we demonstrate that the gene gpoA, encoding for a glutathione peroxidase, is important for the oxidative stress response of the macroalgal pathogen Nautella italica R11. We also show that a lack of gpoA prevents N. italica R11 from inducing a bleaching disease in the red alga Delisea pulchra. These results show that a defense against oxidative stress is likely to be an important feature enabling pathogenic bacteria to infect macroalgae.