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GC-MS based targeted metabolic profiling identifies changes in the wheat metabolome following deoxynivalenol treatment.

Warth B, Parich A, Bueschl C, Schoefbeck D, Neumann NK, Kluger B, Schuster K, Krska R, Adam G, Lemmens M, Schuhmacher R - Metabolomics (2014)

Bottom Line: The results suggest that the primary carbohydrate metabolism and transport, the citric acid cycle and the primary nitrogen metabolism of wheat are clearly affected by DON treatment.Most importantly significantly elevated levels of amino acids and derived amines were observed.The overall workflow proved to be feasible and facilitated to obtain a more comprehensive picture on the effect of DON on the central metabolism of wheat.

View Article: PubMed Central - PubMed

Affiliation: Department for Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry and Institute for Biotechnology in Plant Production, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad-Lorenz-Str. 20, 3430 Tulln, Austria.

ABSTRACT

Fusarium graminearum and related species commonly infest grains causing the devastating plant disease Fusarium head blight (FHB) and the formation of trichothecene mycotoxins. The most relevant toxin is deoxynivalenol (DON), which acts as a virulence factor of the pathogen. FHB is difficult to control and resistance to this disease is a polygenic trait, mainly mediated by the quantitative trait loci (QTL) Fhb1 and Qfhs.ifa-5A. In this study we established a targeted GC-MS based metabolomics workflow comprising a standardized experimental setup for growth, treatment and sampling of wheat ears and subsequent GC-MS analysis followed by data processing and evaluation of QC measures using tailored statistical and bioinformatics tools. This workflow was applied to wheat samples of six genotypes with varying levels of Fusarium resistance, treated with either DON or water, and harvested 0, 12, 24, 48 and 96 h after treatment. The results suggest that the primary carbohydrate metabolism and transport, the citric acid cycle and the primary nitrogen metabolism of wheat are clearly affected by DON treatment. Most importantly significantly elevated levels of amino acids and derived amines were observed. In particular, the concentrations of the three aromatic amino acids phenylalanine, tyrosine, and tryptophan increased. No clear QTL specific difference in the response could be observed except a generally faster increase in shikimate pathway intermediates in genotypes containing Fhb1. The overall workflow proved to be feasible and facilitated to obtain a more comprehensive picture on the effect of DON on the central metabolism of wheat.

No MeSH data available.


Related in: MedlinePlus

Time line of metabolite abundances of glycolysis intermediates (a), TCA cycle metabolites (b) and derived keto acids, amino acids and amines (c). Deoxynivalenol treatment is depicted in black, whereas mock treated samples are blue; whiskers describe the standard deviation. The y-axis gives the normalized relative metabolite abundance. Glycolysis products exhibited decreased levels after DON treatment (a) while molecules included in the TCA cycle (b) and derived keto acids, amino acids and amines (c) seemed to be stimulated by treatment (Color figure online)
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Fig4: Time line of metabolite abundances of glycolysis intermediates (a), TCA cycle metabolites (b) and derived keto acids, amino acids and amines (c). Deoxynivalenol treatment is depicted in black, whereas mock treated samples are blue; whiskers describe the standard deviation. The y-axis gives the normalized relative metabolite abundance. Glycolysis products exhibited decreased levels after DON treatment (a) while molecules included in the TCA cycle (b) and derived keto acids, amino acids and amines (c) seemed to be stimulated by treatment (Color figure online)

Mentions: The heatmap cluster (C) contains metabolites which exhibited moderate concentration increases following DON treatment. Interestingly, a number of metabolites in this cluster belong to the TCA cycle (citric/isocitric acid, succinic acid, fumaric acid, malic acid). In Fig. 4 the increase in TCA intermediates and the decrease of glycolysis related metabolites is illustrated in detail for all investigated genotypes. These observations could point at the need of the plant to generate energy and reduction equivalents to cope with the toxin. Also after the application of the SnToxA effector protein onto wheat (another fungal toxin produced by the pathogen Stagonospora nodorum) photosynthesis decreased and metabolites involved in the TCA cycle increased in general (Vincent et al. 2011). The activation of plant defence actions requires an enhanced energy supply that presumably is mainly derived from photosynthesis, but also seems to require greater respiratory rates (Bolton 2009). In line with the moderate increase in TCA cycle intermediates, also derived keto acids which are precursors of amino acids were elevated. For example 2-ketoglutaric acid is used to form glutamic acid through transamination and both metabolites are increased upon DON treatment under the tested conditions. In analogy, glutamine and pyroglutamic acid (a derivative where the free amino group of glutamine or glutamic acid is cyclized to a lactam) as well as aspartic acid and asparagine were more abundant.Fig. 4


GC-MS based targeted metabolic profiling identifies changes in the wheat metabolome following deoxynivalenol treatment.

Warth B, Parich A, Bueschl C, Schoefbeck D, Neumann NK, Kluger B, Schuster K, Krska R, Adam G, Lemmens M, Schuhmacher R - Metabolomics (2014)

Time line of metabolite abundances of glycolysis intermediates (a), TCA cycle metabolites (b) and derived keto acids, amino acids and amines (c). Deoxynivalenol treatment is depicted in black, whereas mock treated samples are blue; whiskers describe the standard deviation. The y-axis gives the normalized relative metabolite abundance. Glycolysis products exhibited decreased levels after DON treatment (a) while molecules included in the TCA cycle (b) and derived keto acids, amino acids and amines (c) seemed to be stimulated by treatment (Color figure online)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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Fig4: Time line of metabolite abundances of glycolysis intermediates (a), TCA cycle metabolites (b) and derived keto acids, amino acids and amines (c). Deoxynivalenol treatment is depicted in black, whereas mock treated samples are blue; whiskers describe the standard deviation. The y-axis gives the normalized relative metabolite abundance. Glycolysis products exhibited decreased levels after DON treatment (a) while molecules included in the TCA cycle (b) and derived keto acids, amino acids and amines (c) seemed to be stimulated by treatment (Color figure online)
Mentions: The heatmap cluster (C) contains metabolites which exhibited moderate concentration increases following DON treatment. Interestingly, a number of metabolites in this cluster belong to the TCA cycle (citric/isocitric acid, succinic acid, fumaric acid, malic acid). In Fig. 4 the increase in TCA intermediates and the decrease of glycolysis related metabolites is illustrated in detail for all investigated genotypes. These observations could point at the need of the plant to generate energy and reduction equivalents to cope with the toxin. Also after the application of the SnToxA effector protein onto wheat (another fungal toxin produced by the pathogen Stagonospora nodorum) photosynthesis decreased and metabolites involved in the TCA cycle increased in general (Vincent et al. 2011). The activation of plant defence actions requires an enhanced energy supply that presumably is mainly derived from photosynthesis, but also seems to require greater respiratory rates (Bolton 2009). In line with the moderate increase in TCA cycle intermediates, also derived keto acids which are precursors of amino acids were elevated. For example 2-ketoglutaric acid is used to form glutamic acid through transamination and both metabolites are increased upon DON treatment under the tested conditions. In analogy, glutamine and pyroglutamic acid (a derivative where the free amino group of glutamine or glutamic acid is cyclized to a lactam) as well as aspartic acid and asparagine were more abundant.Fig. 4

Bottom Line: The results suggest that the primary carbohydrate metabolism and transport, the citric acid cycle and the primary nitrogen metabolism of wheat are clearly affected by DON treatment.Most importantly significantly elevated levels of amino acids and derived amines were observed.The overall workflow proved to be feasible and facilitated to obtain a more comprehensive picture on the effect of DON on the central metabolism of wheat.

View Article: PubMed Central - PubMed

Affiliation: Department for Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry and Institute for Biotechnology in Plant Production, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad-Lorenz-Str. 20, 3430 Tulln, Austria.

ABSTRACT

Fusarium graminearum and related species commonly infest grains causing the devastating plant disease Fusarium head blight (FHB) and the formation of trichothecene mycotoxins. The most relevant toxin is deoxynivalenol (DON), which acts as a virulence factor of the pathogen. FHB is difficult to control and resistance to this disease is a polygenic trait, mainly mediated by the quantitative trait loci (QTL) Fhb1 and Qfhs.ifa-5A. In this study we established a targeted GC-MS based metabolomics workflow comprising a standardized experimental setup for growth, treatment and sampling of wheat ears and subsequent GC-MS analysis followed by data processing and evaluation of QC measures using tailored statistical and bioinformatics tools. This workflow was applied to wheat samples of six genotypes with varying levels of Fusarium resistance, treated with either DON or water, and harvested 0, 12, 24, 48 and 96 h after treatment. The results suggest that the primary carbohydrate metabolism and transport, the citric acid cycle and the primary nitrogen metabolism of wheat are clearly affected by DON treatment. Most importantly significantly elevated levels of amino acids and derived amines were observed. In particular, the concentrations of the three aromatic amino acids phenylalanine, tyrosine, and tryptophan increased. No clear QTL specific difference in the response could be observed except a generally faster increase in shikimate pathway intermediates in genotypes containing Fhb1. The overall workflow proved to be feasible and facilitated to obtain a more comprehensive picture on the effect of DON on the central metabolism of wheat.

No MeSH data available.


Related in: MedlinePlus