Protoplasma

, Volume 193, Issue 1, pp 123–131

Cellular interactions between arbuscular mycorrhizal fungi and rhizosphere bacteria

  • V. Bianciotto
  • D. Minerdi
  • S. Perotto
  • P. Bonfante
Article

DOI: 10.1007/BF01276640

Cite this article as:
Bianciotto, V., Minerdi, D., Perotto, S. et al. Protoplasma (1996) 193: 123. doi:10.1007/BF01276640

Summary

We have investigated whether direct physical interactions occur between arbuscular mycorrhizal (AM) fungi and plant growth promoting rhizobacteria (PGPRs), some of which are used as biocontrol agents. Attachment of rhizobia and pseudomonads to the spores and fungal mycelium ofGigaspora margarita has been assessed in vitro and visualized by a combination of electron and confocal microscopy. The results showed that both rhizobia and pseudomonads adhere to spores and hyphae of AM fungi germinated under sterile conditions, although the degree of attachment depended upon the strain.Pseudomonas fluorescens strain WCS 365 andRhizobium leguminosarum strains B556 and 3841 were the most effective colonizers. Extracellular material of bacterial origin containing cellulose produced around the attached bacteria may mediate fungal/bacterial interactions. These results suggest that antagonistic and synergistic interactions between AM fungi and rhizosphere bacteria may be mediated by soluble factors or physical contact. They also support the view that AM fungi are a vehicle for the colonization of plant roots by soil rhizobacteria.

Keywords

Pseudomonas fluorescensRhizobiutm leguminosarumGigaspora margaritaCell-to-cell adhesionCell surface

Abbreviations

AM

arbuscular mycorrhiza

PGPR

plant growth promoting rhizobacteria

CBH

cellobiohydrolase

DAPG

2,4-(diacetyl-phloroglucinol

TY

triptone-yeast

LB

Lauria-Bertani

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • V. Bianciotto
    • 1
  • D. Minerdi
    • 1
  • S. Perotto
    • 1
  • P. Bonfante
    • 1
  1. 1.Dipartimento Biologia VegetaleUniversità di TorinoTorinoItaly