Phages of phytopathogenic bacteria: High potential, but challenging application

Phytopathogenic bacteria are one of the most significant causes of crop yield losses. Until now, the direct treatment of bacterioses was limited to the application of antibacterial compounds or resistance inducers. This is about to change due to the revolutionary discovery of phages. Indeed, bacteriophages look very promising as therapy agents: cheap, self-amplifying, self-eliminating, and safe for the host organism. However, phage therapy of plant diseases remains a "direction with high potential", which, so far, has very few successful implication cases. Here, we discuss recent advances in phage research, focusing on the challenges associated with the evaluation of phage biological activity, under both laboratory and environmental conditions.