Salmonella exploits the reactive oxygen species generated by the plant immune system to enhance colonization

Understanding bacterial interaction with the plant immune system is essential for building a sustainable food system. Discouraging pathogens enhancing beneficial bacteria and preventing food spoilage and contamination by human enteric pathogens. Immune system activation triggers a burst of toxic reactive oxygen species (ROS). We discovered that the food-poisoning bacterium Salmonella exploits the plant ROS to enhance biofilm formation and colonization. Scavenging the ROS with antioxidants or inhibiting their production reduces colonization. Further, combining the antioxidant vitamin C and immune system activation with salicylic acid synergistically inhibited Salmonella colonization of the plant model Arabidopsis and edible plants. This safe-to-use combination is an eco-friendly method to prevent plant contamination by Salmonella, Listeria and enteropathogenic E. coli. Finally, we have found that exploiting the plant immunity for enhancing colonization is not exclusive to Salmonella and diverse beneficial pseudomonas species isolated from plants can also exploit the plant immune system, suggesting that it is a general plant colonization strategy.