The quest for a unified view of bacterial land colonization

ISME J. 2014 Jul;8(7):1358-69. doi: 10.1038/ismej.2013.247. Epub 2014 Jan 23.


Exploring molecular mechanisms underlying bacterial water-to-land transition represents a critical start toward a better understanding of the functioning and stability of the terrestrial ecosystems. Here, we perform comprehensive analyses based on a large variety of bacteria by integrating taxonomic, phylogenetic and metagenomic data, in the quest for a unified view that elucidates genomic, evolutionary and ecological dynamics of the marine progenitors in adapting to nonaquatic environments. We hypothesize that bacterial land colonization is dominated by a single-gene sweep, that is, the emergence of dnaE2 derived from an early duplication event of the primordial dnaE, followed by a series of niche-specific genomic adaptations, including GC content increase, intensive horizontal gene transfer and constant genome expansion. In addition, early bacterial radiation may be stimulated by an explosion of land-borne hosts (for example, plants and animals) after initial land colonization events.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Animals
  • Aquatic Organisms / genetics
  • Aquatic Organisms / pathogenicity
  • Bacteria / classification
  • Bacteria / genetics*
  • Base Composition
  • Biological Evolution
  • DNA Polymerase III / genetics*
  • Ecosystem*
  • Gene Transfer, Horizontal
  • Genome, Bacterial*
  • Metagenome*
  • Phylogeny*
  • Plants / microbiology


  • DNA Polymerase III
  • DNA polymerase III, alpha subunit