Tropical soils are a reservoir for fluorescent Pseudomonas spp. biodiversity

Environ Microbiol. 2018 Jan;20(1):62-74. doi: 10.1111/1462-2920.13957. Epub 2017 Nov 10.

Abstract

Fluorescent Pseudomonas spp. are widely studied for their beneficial activities to plants. To explore the genetic diversity of Pseudomonas spp. in tropical regions, we collected 76 isolates from a Brazilian soil. Genomes were sequenced and compared to known strains, mostly collected from temperate regions. Phylogenetic analyses classified the isolates in the P. fluorescens (57) and P. putida (19) groups. Among the isolates in the P. fluorescens group, most (37) were classified in the P. koreensis subgroup and two in the P. jessenii subgroup. The remaining 18 isolates fell into two phylogenetic subclades distinct from currently recognized P. fluorescens subgroups, and probably represent new subgroups. Consistent with their phylogenetic distance from described subgroups, the genome sequences of strains in these subclades are asyntenous to the genome sequences of members of their neighbour subgroups. The tropical isolates have several functional genes also present in known fluorescent Pseudomonas spp. strains. However, members of the new subclades share exclusive genes not detected in other subgroups, pointing to the potential for novel functions. Additionally, we identified 12 potential new species among the 76 isolates from the tropical soil. The unexplored diversity found in the tropical soil is possibly related to biogeographical patterns.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Base Sequence
  • Biodiversity*
  • Brazil
  • DNA, Bacterial / genetics
  • Genome, Bacterial / genetics*
  • Phylogeny
  • Plants / microbiology
  • Pseudomonas fluorescens* / classification
  • Pseudomonas fluorescens* / genetics
  • Pseudomonas fluorescens* / isolation & purification
  • Pseudomonas putida* / classification
  • Pseudomonas putida* / genetics
  • Pseudomonas putida* / isolation & purification
  • Sequence Analysis, DNA
  • Soil
  • Soil Microbiology

Substances

  • DNA, Bacterial
  • Soil