show Abstracthide AbstractA population study of Rathayibacter toxicus from Australia, as well as a paired population of a related novel Rathayibacter species primarily found in Oregon. Several other Rathayibacter species were examined as well. The work reveals the ecological role of CRISPR in Rathayibacter toxicus and uses the novel Rathayibacter species as a comparison where a CRISPR-phage interaction is not involved in the evolution of the bacteria.