Submitted to: American Society of Pharmacognosy
Publication Type: Abstract Only
Publication Acceptance Date: July 30, 1997
Publication Date: N/A
Technical Abstract: Treatment of wheat seeds with cells of Pseudomonas fluorescens 2-79 suppresses take-all root disease caused by Gaeumannomyces graminis var. tritici. Inclusion of spent fermentation broth in seed coating formulations causes significant losses in seed germination. A metabolite other than phenazine-1-carboxylic acid (strain 2-79's major mechanism of antifungal action) was detected in inhibitory seed formulations and in fermentation broth. The unknown was purified by column and thin-layer chromatography (isolated yield ~8 mg/L culture supernatant). The purified compound was tentatively identified by EIMS, **1H- and **13C-NMR as 2-acetamidophenol. Identification was confirmed by comparisons of chromatographic and spectral data with those from a 2-acetamidophenol standard. Seed germination bioassays revealed that inhibitory activity of strain 2-79 may be caused by a combination of 2-acetamidophenol, phenazine-1-carboxylic acid and other formulation factors.