Application of Toxigenic Alternaria oxytropis to Soybeans and its Effect on Swainsonine Detection in Different Environments

Bull Environ Contam Toxicol. 2019 Feb;102(2):268-274. doi: 10.1007/s00128-018-2496-0. Epub 2018 Nov 23.

Abstract

Alternaria oxytropis is an endophytic fungus of locoweeds that synthesizes swainsonine toxin. In this work, we evaluated the effect of A. oxytropis on soybean seedlings and quantified swainsonine in different culture conditions. Soybean (Glycine max) seeds were co-cultured with A. oxytropis (at different concentrations of mycelial suspensions) in agar media and soil culture, and swainsonine was assayed using LC-MS/MS. The results showed evidence that A. oxytropis infected soybean seedlings produced detectable swainsonine in agar culture while the toxin was undetectable or below the detection limit (0.006% of swainsonine dry weight) in soil media even at higher concentrations of the fungus. These results suggest that swainsonine detection is highly dependent on culture conditions and that soybeans co-cultured with A. oxytropis in soil could potentially be used to limit toxin production.

Keywords: Alkaloid toxin; Alternaria oxytropis; Locoweeds; Soybean; Swainsonine; Toxin detection.

MeSH terms

  • Alternaria / pathogenicity*
  • Chromatography, Liquid
  • Coculture Techniques
  • Host-Pathogen Interactions
  • Limit of Detection
  • Oxytropis
  • Seedlings / growth & development
  • Seedlings / microbiology
  • Soybeans / microbiology*
  • Swainsonine / analysis*
  • Tandem Mass Spectrometry

Substances

  • Swainsonine