The emergence of disease-preventing bacteria within the plant microbiota.

Microbiome studies have facilitated the discovery of harmful as well as beneficial microorganisms over the last years. Recently, distinct bacteria were found within the microbiota of crop plants that confer disease resistance to their hosts. Although it is well known that the interplay between microbes and plants can result in improved plant health, the phenomenon of holistically disease-preventing bacteria is new. Here, we put the recent discoveries of disease-preventing bacteria in context with decade-long plant microbiome research that has preceded them. In addition, we provide explanations as to why disease resistance in certain plants, mediated by specific bacteria, has only recently been discovered. We argue that such findings were primarily limited by technological constraints and that analogous findings are very likely to be made with other plant species. The general concept may even be extendable to additional groups of organisms. We, therefore, suggest the introduction of the specific term soterobiont in order to facilitate an unambiguous definition of disease-preventing microorganisms within the microbiota of higher organisms.