RT Journal Article
SR Electronic
T1 Microbial community assembly differs by mineral type in the rhizosphere
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 128850
DO 10.1101/128850
A1 Thea Whitman
A1 Rachel Neurath
A1 Adele Perera
A1 Daliang Ning
A1 Jizhong Zhou
A1 Peter Nico
A1 Jennifer Pett-Ridge
A1 Mary Firestone
YR 2017
UL http://biorxiv.org/content/early/2017/04/20/128850.abstract
AB Inputs of root carbon (C) fuel growth of nearby soil microorganisms. If these microbes associate with soil minerals, then mineral-microbiome complexes near roots could be a gateway towards stabilization of soil carbon and may influence the quantity and quality of persistent SOM. To investigate the interactions between roots, soil minerals, and microbes, we incubated three types of minerals (ferrihydrite, kaolinite, quartz) and a native soil mineral fraction near roots of a common Californian annual grass, Avena barbata, growing in its resident soil. We followed microbial colonization of these minerals for 2.5 months – the plant’s lifespan. Bacteria and fungi that colonized mineral surfaces during this experiment differed across mineral types and differed from those in the background soil, implying microbial colonization was the result of processes in addition to passive movement with water to mineral surfaces. Null model analysis revealed that dispersal limitation was a dominant factor structuring mineral-associated microbial communities for all mineral types. Once bacteria arrived at a mineral surface, capacity for rapid growth appeared important, as ribosomal copy number was significantly correlated with relative enrichment on minerals. Glomeromycota (a phylum associated with arbuscular mycorrhizal fungi) appeared to preferentially associate with ferrihydrite surfaces. The mechanisms enabling colonization of soil minerals may be foundational to the overall soil microbiome composition and partially responsible for the persistence of C entering soil via plant roots.