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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research » Research » Publications at this Location » Publication #248314

Title: Three Strains of Pseudomonas fluorescens Exhibit Differential Toxicity Against Drosophila melanogaster

item Olcott, Marika
item Rosen, Kise
item Walker, Francesca
item Sneh, Baruch
item Loper, Joyce
item Taylor, Barbara

Submitted to: International Plant Growth Promoting Rhizobacteria Workshop
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2009
Publication Date: 5/17/2009
Citation: Olcott, M., Rosen, K., Walker, F., Sneh, B., Loper, J.E., Taylor, B. 2009. Three strains of Pseudomonas fluorescens exhibit differential toxicity against Drosophila melanogaster. International Plant Growth Promoting Rhizobacteria Workshop. p. 71.

Interpretive Summary:

Technical Abstract: Three strains of Pseudomonas fluorescens were tested for toxicity to Drosophila melanogaster in an insect feeding assay. Insect eggs were placed on the surface of a non-nutritive agar plate supplemented with a food source that was non-inoculated or inoculated with P. fluorescens Pf0-1, SBW25, or Pf-5, and insect development and survival were evaluated over time. Strain Pf0-1 had no significant effect on insect survival and development, whereas strain Pf-5 caused dose-dependent lethality and morphological defects in eyes and wings in the surviving adult flies. In addition, Pf-5 caused a dose dependent delay in the onset of metamorphosis relative to non-inoculated controls. A gacA mutant of Pf-5 caused no significant mortality, morphological defects, or developmental delay, indicating that factors responsible for these effects are controlled by the GacS/GacA global regulatory system. Strain SBW25 also caused insect mortality, but to a lower level than caused by Pf-5, and surviving larvae did not exhibit developmental delays. Strain SBW25 ingestion caused some insects to exhibit a profound, fatal systemic melanization reaction at larval, pupal or adult stages. These experiments demonstrate that P. fluorescens Pf-5 and SBW25, when introduced through natural routes of infection, can cause mortality of D. melanogaster. Furthermore, strain Pf-5 causes delays in the onset of metamorphosis and produces morphological defects in surviving adult flies that are independent of host survival.