biostudies-literatureOgran AIsrael Science Foundatione00512-19https://www.ebi.ac.uk/biostudies/studies/S-EPMC6581183biostudies-literatureUnknown85(13)Microbial ecosystems tightly associated with a eukaryotic host are widespread in nature. The genetic and metabolic networks of the eukaryotic hosts and the associated microbes have coevolved to form a symbiotic relationship. Both the Gram-positive Bacillus subtilis and the Gram-negative Serratia plymuthica can form biofilms on plant roots and thus can serve as a model system for the study of interspecies interactions in a host-associated ecosystem. We found that B. subtilis biofilms expand collectively and asymmetrically toward S. plymuthica, while expressing a nonribosomal antibiotic bacillaene and an extracellular protease. As a result, B. subtilis biofilms outcompeted S. plymuthica for successful colonization of the host. Strikingly, the plant host was able to enhance the efficiency of Applied and environmental microbiologyThe Plant Host Induces Antibiotic Production To Select the Most-Beneficial Colonizers.PMC6581183119/2016152/1 IcoreJain RBucher TKeren-Paz AKolodkin-Gal IGilhar OOgran AYardeni EHfalseThe Plant Host Induces Antibiotic Production To Select the Most-Beneficial Colonizers.Microbial ecosystems tightly associated with a eukaryotic host are widespread in nature. The genetic and metabolic networks of the eukaryotic hosts and the associated microbes have coevolved to form a symbiotic relationship. Both the Gram-positive Bacillus subtilis and the Gram-negative Serratia plymuthica can form biofilms on plant roots and thus can serve as a model system for the study of interspecies interactions in a host-associated ecosystem. We found that B. subtilis biofilms expand collectively and asymmetrically toward S. plymuthica, while expressing a nonribosomal antibiotic bacillaene and an extracellular protease. As a result, B. subtilis biofilms outcompeted S. plymuthica for successful colonization of the host. Strikingly, the plant host was able to enhance the efficiency of 2019-01-01T00:00:00Z2019 Jul2025-05-29T22:06:14.098Z2025-05-29T22:06:14.098ZS-EPMC65811833100398410.1128/AEM.00512-1910.1128/aem.00512-19