Biology and Fertility of Soils

, Volume 45, Issue 6, pp 669–674

A diazotrophic, indole-3-acetic acid-producing endophyte from wild cottonwood

  • Gang Xin
  • Gengyun Zhang
  • Jun Won Kang
  • James T. Staley
  • Sharon L. Doty
Short Communication

DOI: 10.1007/s00374-009-0377-8

Cite this article as:
Xin, G., Zhang, G., Kang, J.W. et al. Biol Fertil Soils (2009) 45: 669. doi:10.1007/s00374-009-0377-8

Abstract

An endophytic bacterium, wild poplar strain B (WPB), isolated from stems of wild cottonwood (Populus trichocarpa) was identified to Burkholderia vietnamiensis by analyzing the recA and rDNA genes. Phylogenetic analysis of the nifHDK cluster indicates that the WPB isolate shares high sequence similarity with known B. vietnamiensis strains. The nitrogenase activity of WPB was determined by a 15N2 incorporation assay and an acetylene reduction assay. WPB was also monitored for production of indole-3-acetic acid (IAA), a phytohormone which can promote plant growth, when incubated with l-tryptophan. In addition, its plant growth promotion capacity was assessed by inoculating the WPB strain onto Kentucky bluegrass in nitrogen-free medium. Compared to uninoculated control plants, the plants inoculated with WPB gained more dry weight (42%, p = 0.01) and more nitrogen content (37%, p = 0.04) in 50 days.

Keywords

Diazotrophic endophytePoplar treesPlant growth promotionBurkholderia vietnamiensisIAAPhylogenetic analysisTurf grassNitrogen fixationPopulusAuxinEndophytes

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Gang Xin
    • 1
    • 4
  • Gengyun Zhang
    • 2
  • Jun Won Kang
    • 2
  • James T. Staley
    • 3
  • Sharon L. Doty
    • 2
  1. 1.Department of Civil and Environmental EngineeringUniversity of WashingtonSeattleUSA
  2. 2.College of Forest ResourcesUniversity of WashingtonSeattleUSA
  3. 3.Department of MicrobiologyUniversity of WashingtonSeattleUSA
  4. 4.HydranauticsOceansideUSA