title: Simplified and representative bacterial community of maize roots.
abstract: Plant-associated microbes are important for the growth and health of their hosts. As a result of numerous prior studies, we know that host genotypes and abiotic factors influence the composition of plant microbiomes. However, the high complexity of these communities challenges detailed studies to define experimentally the mechanisms underlying the dynamics of community assembly and the beneficial effects of such microbiomes on plant hosts. In this work, from the distinctive microbiota assembled by maize roots, through host-mediated selection, we obtained a greatly simplified synthetic bacterial community consisting of seven strains (Enterobacter cloacae,Stenotrophomonas maltophilia, Ochrobactrum pituitosum, Herbaspirillum frisingense, Pseudomonas putida, Curtobacterium pusillum, andChryseobacterium indologenes) representing three of the four most dominant phyla found in maize roots. By using a selective culture-dependent method to track the abundance of each strain, we investigated the role that each plays in community assembly on roots of axenic maize seedlings. Only the removal ofE. cloacaeled to the complete loss of the community, andC. pusillumtook over. This result suggests thatE. cloacaeplays the role of keystone species in this model ecosystem.In plantaand in vitro, this model community inhibited the phytopathogenic fungusFusarium verticillioides, indicating a clear benefit to the host. Thus, combined with the selective culture-dependent quantification method, our synthetic seven-species community representing the root microbiome has the potential to serve as a useful system to explore how bacterial interspecies interactions affect root microbiome assembly and to dissect the beneficial effects of the root microbiota on hosts under laboratory conditions in the future.
authors.affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115.
authors.forename: Ben
authors.initials: B
authors.lastname: Niu
authors.affiliation: Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA 02115.|Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, MA 02115.
authors.forename: Joseph Nathaniel
authors.initials: JN
authors.lastname: Paulson
authors.affiliation: Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA 02115.|Department of Mathematics, Shanghai Normal University, Shanghai 200234, China.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115; roberto_kolter@hms.harvard.edu.
authors.forename: Roberto
authors.initials: R
authors.lastname: Kolter
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D064307:Microbiota; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D012988:Soil Microbiology; D003313:Zea mays / Q000382:microbiology*
keywords: biological control; community assembly; maize; synthetic community