Mycelia as a focal point for horizontal gene transfer among soil bacteria.
Horizontal gene transfer (HGT) is a main mechanism of bacterial evolution endowing bacteria with new genetic traits. The transfer of mobile genetic elements such as plasmids (conjugation) requires the close proximity of cells. HGT between genetically distinct bacteria largely depends on cell movement in water films, which are typically discontinuous in natural systems like soil. Using laboratory microcosms, a bacterial reporter system and flow cytometry, we here investigated if and to which degree mycelial networks facilitate contact of and HGT between spatially separated bacteria. Our study shows that the network structures of mycelia promote bacterial HGT by providing continuous liquid films in which bacterial migration and contacts are favoured. This finding was confirmed by individual-based simulations, revealing that the tendency of migrating bacteria to concentrate in the liquid film around hyphae is a key factor for improved HGT along mycelial networks. Given their ubiquity, we propose that hyphae can act as focal point for HGT and genetic adaptation in soil.
Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany.
Tom
T
Berthold
Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany.
Florian
F
Centler
Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany.
Thomas
T
Hübschmann
Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany.
Rita
R
Remer
Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany.
Martin
M
Thullner
Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany.|German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5E, 04103 Leipzig, Germany.
Hauke
H
Harms
Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany.
Lukas Y
LY
Wick
D001419:Bacteria / Q000235:genetics*; D018407:Bacterial Physiological Phenomena; D022761:Gene Transfer, Horizontal; D014644:Genetic Variation; D025282:Mycelium / Q000502:physiology*; D012988:Soil Microbiology