Commensal Pseudomonas fluorescens Strains Protect <i>Arabidopsis</i> from Closely Related Pseudomonas Pathogens in a Colonization-Dependent Manner
Nicole R. Wang, Christina L. Wiesmann, Ryan A. Melnyk, Sarzana S. Hossain, Myoung‐Hwan Chi, Kitoosepe Martens, Kelly D. Craven, Cara H. Haney
Abstract
Microbiota can protect diverse hosts from pathogens, and microbiome dysbiosis can result in increased vulnerability to opportunistic pathogens. Here, we developed a rhizosphere commensal-pathogen model to identify bacterial strains and mechanisms that can protect plants from an opportunistic Pseudomonas pathogen. Our finding that protective strains are closely related to the pathogen suggests that the presence of specific microbial taxa may help protect plants from disease. We found that commensal colonization level was highly correlated with protection, suggesting that competition with pathogens may play a role in protection. As we found that commensal Pseudomonas were also able to protect against an agricultural pathogen, this system may be broadly relevant for identifying strains and mechanisms to control agriculturally important pathogens. This work also suggests that beneficial plant-associated microbes may be useful for engineering soils where microbial complexity is low, such as hydroponic, or disturbed agricultural soils.