The presence of mycorrhizal-root associations markedly alters the quality of carbon flow from roots. We investigated how antibiotic production of the model Pseudomonas fluorescens strains were modulated by qualitative changes to C-flow. Specifically, we quantified the production of the antibiotic 2,4-diacetylphloroglucinol (DAPG), a known suppressant of root fungal pathogens. In the first experiment, wheat plants were grown for five weeks in sand inside split pots so that half of their root systems were colonised by arbuscular mycorrhizal fungi and half remained uncolonised. In the second experiment, wheat plants were grown without mycorrhizal fungi, with mycorrhizal fungi and with the root pathogen Gaeumannomyces graminis var. tritici (Ggt) and with both mycorrhizal fungi and Ggt. Roots were harvested and homogenate was used to challenge cultures of P. fluorescens strains. Each homogenate was balanced for molar C. To increase sample throughput and analytical efficiency, we used a 96-well plate Porvair Sciences Ltd Microlute® system containing a C-18 Solid Phase Extraction matrix. The analyte of interest (DAPG) in each cell in the growth plate was retained on the C-18 matrix until elution by methanol for HPLC analysis. We discuss how the presence of the arbuscular mycorrhizal fungi and Ggt affects the antibiotic production by root associated bacteria.
|Publication status||Published - 2008|
|Event||Eurosoil - Vienna, Austria|
Duration: 25 Aug 2008 → 29 Aug 2008
|Period||25/08/08 → 29/08/08|