Mycorrhization helper bacteria: a case of specificity for altering ectomycorrhiza architecture but not ectomycorrhiza formation

Thomas J. Aspray, Pascale Frey-Klett, Julie E. Jones, John M. Whipps, Jean Garbaye, Gary D. Bending

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    34 Citations (Scopus)

    Abstract

    Mycorrhization helper bacteria (MHB), isolated from phylogenetically distinct ectomycorrhizal symbioses involving Lactarius rufus, Laccaria bicolor or Suillus luteus, were tested for fungus specificity to enhance L. rufus-Pinus sylvestris or L. bicolor-P. sylvestris mycorrhiza formation. As MHB isolated from the L. rufus and S. luteus mycorrhiza were originally characterised using a microcosm system, we assessed their ability to enhance mycorrhiza formation in a glasshouse system in order to determine the extent to which MHB are system-specific. Paenibacillus sp. EJP73, an MHB for L. rufus in the microcosm, significantly enhanced L. bicolor mycorrhiza formation in the glasshouse, demonstrating that the MHB effect of this bacterium is neither fungus-specific nor limited to the original experimental system. Although the five MHB strains studied were unable to significantly enhance L. rufus mycorrhiza formation, two of them did have a significant effect on dichotomous short root branching by L. rufus. The effect was specific to Paenibacillus sp. EJP73 and Burkholderia sp. EJP67, the two strains isolated from L. rufus mycorrhiza, and was not associated with auxin production. Altered mycorrhiza architecture rather than absolute number of mycorrhizal roots may be an important previously overlooked parameter for defining MHB effects.

    Original languageEnglish
    Pages (from-to)533-541
    Number of pages9
    JournalMycorrhiza
    Volume16
    Issue number8
    DOIs
    Publication statusPublished - Nov 2006

    Keywords

    • ectomycorrhizal fungi
    • Laccaria bicolor
    • Lactarius rufus
    • mycorrhization helper bacteria
    • Pinus sylvestris
    • LACCARIA-BICOLOR
    • DOUGLAS-FIR
    • FLUORESCENT PSEUDOMONADS
    • FOREST NURSERIES
    • DUAL INOCULATION
    • SYMBIOSIS
    • FUNGUS
    • SOIL
    • SURVIVAL
    • GROWTH

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