alternariol and deoxynivalenol

Fluorescent pseudomonads colonizing wheat ears have a high antagonistic potential against phytopathogenic fungi. To check this hypothesis, the bacterial antagonist Pseudomonas simiae 9

Topics: Alternaria; Antibiosis; Biological Control Agents; Fusarium; Lactones; Mycotoxins; Pseudomonas; Tenuazonic Acid; Trichothecenes; Triticum; Zearalenone

To observe the variation in accumulation of Fusarium and Alternaria mycotoxins across a topographically heterogeneous field and tested biotic (fungal and bacterial abundance) and abiotic (microclimate) parameters as explanatory variables.. We selected a wheat field characterized by a diversified topography, to be responsible for variations in productivity and in canopy-driven microclimate. Fusarium and Alternaria mycotoxins where quantified in wheat ears at three sampling dates between flowering and harvest at 40 points. Tenuazonic acid (TeA), alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), deoxynivalenol (DON), zearalenone (ZEN) and deoxynivalenol-3-Glucoside (DON.3G) were quantified. In canopy temperature, air and soil humidity were recorded for each point with data-loggers. Fusarium spp. as trichothecene producers, Alternaria spp. and fungal abundances were assessed using qPCR. Pseudomonas fluorescens bacteria were quantified with a culture based method. We only found DON, DON.3G, TeA and TEN to be ubiquitous across the whole field, while AME, AOH and ZEN were only occasionally detected. Fusarium was more abundant in spots with high soil humidity, while Alternaria in warmer and drier spots. Mycotoxins correlated differently to the observed explanatory variables: positive correlations between DON accumulation, tri 5 gene and Fusarium abundance were clearly detected. The correlations among the others observed variables, such as microclimatic conditions, varied among the sampling dates. The results of statistical model identification do not exclude that species coexistence could influence mycotoxin production.. Fusarium and Alternaria mycotoxins accumulation varies heavily across the field and the sampling dates, providing the realism of landscape-scale studies. Mycotoxin concentrations appear to be partially explained by biotic and abiotic variables.. We provide a useful experimental design and useful data for understanding the dynamics of mycotoxin biosynthesis in wheat.

Topics: Alternaria; Food Contamination; Fusarium; Glucosides; Lactones; Microclimate; Mycotoxins; Pseudomonas fluorescens; Secondary Metabolism; Soil Microbiology; Tenuazonic Acid; Trichothecenes; Triticum; Zearalenone

Enniatin B (ENN B), deoxinivalenol (DON) and alternariol (AOH) are secondary metabolites of filamentous fungi. These mycotoxins are contaminants of vegetables and cereals. They are cytotoxic and their effects are enhanced by their mixtures. The objectives of this study were to compare the cytotoxicity of ENN B, DON and AOH alone or in combination in human adenocarcinoma (Caco-2) cells and to evaluate the type of interactions of mycotoxin mixtures by the isobologram analysis. Cells were treated with concentrations ranging from 1.85 to 90μM (AOH) and from 0.312 to 10μM (for ENN B and DON), individually and in combination of two and three mycotoxins (from 1.85 to 30μM for AOH and from 0.312 to 5μM for ENN B and DON). The relation ratios between the mixtures DON+ENN B was 1:1; AOH+DON and ENN B+AOH was 1:6, and for the tertiary combination DON, ENN B and AOH 1:1:6. The IC50 value of ENN B and DON were 3.87 and 5.54μM, respectively. No IC50 values were obtained for the AOH at any time tested in Caco-2 cells. With the isobologram the type of interaction between mycotoxin was evaluated. Synergistic, antagonistic and addictive effect was observed for the combination studied depending on the concentration affected. Mycotoxins combinations reduce cellular viability in the following increasing order: (DON+ENN B)>(ENN B+AOH)>(DON+AOH)>(DON+AOH+ENN B).

Topics: Caco-2 Cells; Cell Survival; Depsipeptides; Drug Interactions; Food Contamination; Humans; Lactones; Mycotoxins; Trichothecenes