title: Plant growth-promoting Burkholderia species isolated from annual ryegrass in Portuguese soils.
abstract: OBJECTIVE
  To search for culturable Burkholderia species associated with annual ryegrass in soils from natural pastures in Portugal, with plant growth-promoting effects.
  
  
  RESULTS
  Annual ryegrass seedlings were used to trap Burkholderia from two different soils in laboratory conditions. A combined approach using genomic fingerprinting and sequencing of 16S rRNA and recA genes resulted in the identification of Burkholderia strains belonging to the species Burkholderia graminis, Burkholderia fungorum and the Burkholderia cepacia complex. Most strains were able to solubilize mineral phosphate and to synthesize indole acetic acid; some of them could produce siderophores and antagonize the phytopathogenic oomycete, Phytophthora cinnamomi. A strain (G2Bd5) of B. graminis was selected for gnotobiotic plant inoculation experiments. The main effects were the stimulation of root growth and enhancement of leaf lipid synthesis and turnover. Fluorescence in situ hybridization and confocal laser microscopy evidenced that strain G2Bd5 is a rhizospheric and endophytic colonizer of annual ryegrass.
  
  
  CONCLUSIONS
  This work revealed that annual ryegrass can naturally associate with members of the genus Burkholderia. A novel plant growth promoting strain of B. graminis was obtained.
  
  
  CONCLUSIONS
  The novel strain belongs to the plant-associated Burkholderia cluster and is a promising candidate for exploitation as plant inoculant in field conditions.
authors.affiliation: Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal.|Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: N
authors.initials: N
authors.lastname: Castanheira
authors.affiliation: iBET-Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal.
authors.forename: A C
authors.initials: AC
authors.lastname: Dourado
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.|iBET-Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal.
authors.forename: S
authors.initials: S
authors.lastname: Kruz
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.|iBET-Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal.
authors.forename: P I L
authors.initials: PI
authors.lastname: Alves
authors.affiliation: Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal.
authors.forename: A I
authors.initials: AI
authors.lastname: Delgado-Rodríguez
authors.affiliation: Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal.
authors.forename: I
authors.initials: I
authors.lastname: Pais
authors.affiliation: Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Semedo
authors.affiliation: Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Scotti-Campos
authors.affiliation: Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Sánchez
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: N
authors.initials: N
authors.lastname: Borges
authors.affiliation: UCBIO, REQUIMTE, Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal.
authors.forename: G
authors.initials: G
authors.lastname: Carvalho
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.|iBET-Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal.
authors.forename: M T
authors.initials: MT
authors.lastname: Barreto Crespo
authors.affiliation: Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Fareleira
mesh_terms: D019117:Burkholderia / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D008129:Lolium / Q000254:growth & development / Q000382:microbiology*; D008969:Molecular Sequence Data; D010710:Phosphates / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development / Q000382:microbiology; D011174:Portugal; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D007210:Indoleacetic Acids; D010710:Phosphates; D012336:RNA, Ribosomal, 16S; D012987:Soil; C030737:indoleacetic acid
keywords: Burkholderia graminis; fluorescence in situ hybridization; plant growth-promoting activities; plant inoculation assays; plant-associated bacteria