Interacting climate change environmental factors effects on Fusarium langsethiae growth, expression of Tri genes and T-2/HT-2 mycotoxin production on oat-based media and in stored oats

Fungal Biol. 2019 Aug;123(8):618-624. doi: 10.1016/j.funbio.2019.04.008. Epub 2019 May 11.

Abstract

This study examined the effect of climate change (CC) abiotic factors of temperature (20, 25, 30 °C), water activity (aw; 0.995, 0.98) and CO2 exposure (400, 1000 ppm) may have on (a) growth, (b) gene expression of biosynthetic toxin genes (Tri5, Tri6, Tri16), and (c) T-2/HT-2 toxins and associated metabolites by Fusarium langsethiae on oat-based media and in stored oats. Lag phases and growth were optimum at 25 °C with freely available water. This was significantly reduced at 30 °C, at 0.98 aw and 1000 ppm CO2 exposure. In oat-based media and stored oats, Tri5 gene expression was reduced in all conditions except 30 °C, 0.98 aw, elevated CO2 where there was a significant (5.3-fold) increase. The Tri6 and Tri16 genes were upregulated, especially in elevated CO2 conditions. Toxin production was higher at 25 °C than 30 °C. In stored oats, at 0.98 aw, elevated CO2 led to a significant increase (73-fold) increase in T2/HT-2 toxin, especially at 30 °C. Nine T-2 and HT-2 related metabolites were detected, including a new dehydro T-2 toxin (which correlated with T-2 production) and the conjugate, HT-2 toxin, glucuronide. This shows that CC factors may have a significant impact on growth and mycotoxin production by F. langsethiae.

Keywords: Biosynthetic genes; Carbon dioxide; Mycotoxins; Small grain cereals; Temperature; Type A trichothecenes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Avena / chemistry*
  • Avena / microbiology*
  • Climate Change
  • Food Contamination / analysis
  • Food Storage
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Fusarium / chemistry
  • Fusarium / genetics*
  • Fusarium / growth & development*
  • Fusarium / metabolism
  • Mycotoxins / analysis*
  • Mycotoxins / metabolism
  • Seeds / chemistry
  • Seeds / microbiology
  • T-2 Toxin / analogs & derivatives
  • T-2 Toxin / analysis
  • T-2 Toxin / biosynthesis
  • T-2 Toxin / metabolism

Substances

  • Fungal Proteins
  • Mycotoxins
  • T-2 Toxin
  • HT-2 toxin