VanInsberghe_2015_ISME.J_9_2435

Reference

Title : Non-symbiotic Bradyrhizobium ecotypes dominate North American forest soils - VanInsberghe_2015_ISME.J_9_2435
Author(s) : VanInsberghe D , Maas KR , Cardenas E , Strachan CR , Hallam SJ , Mohn WW
Ref : Isme J , 9 :2435 , 2015
Abstract :

The genus Bradyrhizobium has served as a model system for studying host-microbe symbiotic interactions and nitrogen fixation due to its importance in agricultural productivity and global nitrogen cycling. In this study, we identify a bacterial group affiliated with this genus that dominates the microbial communities of coniferous forest soils from six distinct ecozones across North America. Representative isolates from this group were obtained and characterized. Using quantitative population genomics, we show that forest soil populations of Bradyrhizobium represent ecotypes incapable of nodulating legume root hairs or fixing atmospheric nitrogen. Instead, these populations appear to be free living and have a greater potential for metabolizing aromatic carbon sources than their close symbiotic relatives. In addition, we identify fine-scaled differentiation between populations inhabiting neighboring soil layers that illustrate how diversity within Bradyrhizobium is structured by habitat similarity. These findings reconcile incongruent observations about this widely studied and important group of bacteria and highlight the value of ecological context to interpretations of microbial diversity and taxonomy. These results further suggest that the influence of this genus likely extends well beyond facilitating agriculture, especially as forest ecosystems are large and integral components of the biosphere. In addition, this study demonstrates how focusing research on economically important microorganisms can bias our understanding of the natural world.

PubMedSearch : VanInsberghe_2015_ISME.J_9_2435
PubMedID: 25909973
Gene_locus related to this paper: 9brad-a0a0d7njr6 , 9brad-a0a0d7nke7 , 9brad-a0a0d7p9x5 , 9brad-a0a0d7pif1 , 9brad-a0a0d7p1j9 , 9brad-a0a0d7qiy7 , 9brad-a0a0d7pry5

Citations formats

VanInsberghe D, Maas KR, Cardenas E, Strachan CR, Hallam SJ, Mohn WW (2015)
Non-symbiotic Bradyrhizobium ecotypes dominate North American forest soils
Isme J 9 :2435

VanInsberghe D, Maas KR, Cardenas E, Strachan CR, Hallam SJ, Mohn WW (2015)
Isme J 9 :2435