title: Arabidopsis thaliana and Pisum sativum models demonstrate that root colonization is an intrinsic trait of Burkholderia cepacia complex bacteria.
abstract: Burkholderia cepacia complex (Bcc) bacteria possess biotechnologically useful properties that contrast with their opportunistic pathogenicity. The rhizosphere fitness of Bcc bacteria is central to their biocontrol and bioremediation activities. However, it is not known whether this differs between species or between environmental and clinical strains. We investigated the ability of 26 Bcc strains representing nine different species to colonize the roots of Arabidopsis thaliana and Pisum sativum (pea). Viable counts, scanning electron microscopy and bioluminescence imaging were used to assess root colonization, with Bcc bacteria achieving mean (±sem) levels of 2.49±0.23×10(6) and 5.16±1.87×10(6) c.f.u. per centimetre of root on the A. thaliana and P. sativum models, respectively. The A. thaliana rhizocompetence model was able to reveal loss of colonization phenotypes in Burkholderia vietnamiensis G4 transposon mutants that had only previously been observed in competition experiments on the P. sativum model. Different Bcc species colonized each plant model at different rates, and no statistical difference in root colonization was observed between isolates of clinical or environmental origin. Loss of the virulence-associated third chromosomal replicon (>1 Mb DNA) did not alter Bcc root colonization on A. thaliana. In summary, Bcc bacteria possess intrinsic root colonization abilities irrespective of their species or source. As Bcc rhizocompetence does not require their third chromosomal replicon, the possibility of using synthetic biology approaches to engineer virulence-attenuated biotechnological strains is tractable.
authors: Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
authors: J Cristian
authors: JC
authors: Vidal-Quist
authors: Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
authors: Louise A
authors: LA
authors: O'Sullivan
authors: Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
authors: Annaëlle
authors: A
authors: Desert
authors: MRC Centre for Molecular Bacteriology and Infection, G20 Flowers Building, Imperial College London, London, UK.
authors: Amanda S
authors: AS
authors: Fivian-Hughes
authors: Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
authors: Coralie
authors: C
authors: Millet
authors: Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
authors: T Hefin
authors: TH
authors: Jones
authors: Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
authors: Andrew J
authors: AJ
authors: Weightman
authors: Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
authors: Hilary J
authors: HJ
authors: Rogers
authors: Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
authors: Colin
authors: C
authors: Berry
authors: Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
authors: Eshwar
authors: E
authors: Mahenthiralingam
mesh_terms: D017360:Arabidopsis / Q000382:microbiology*; D019121:Burkholderia Infections / Q000382:microbiology; D042602:Burkholderia cepacia complex / Q000254:growth & development* / Q000302:isolation & purification; D015169:Colony Count, Microbial; D004251:DNA Transposable Elements; D004783:Environmental Microbiology; D008855:Microscopy, Electron, Scanning; D016254:Mutagenesis, Insertional; D061848:Optical Imaging; D018532:Pisum sativum / Q000382:microbiology*; D018517:Plant Roots / Q000382:microbiology*
chemical_list: D004251:DNA Transposable Elements