The role of cell wall-based defences in the early restriction of non-pathogenic hrp mutant bacteria in Arabidopsis

Accumulation of reactive oxygen species was identified as the first plant response differentiating between wild-type and hrp mutant bacteria in Arabidopsis. The image shows detection of ROS in chloroplasts causing pale green fluorescence after staining with H2DCFDA 4 h after inoculation with the hrpA mutant.