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Tulln, Austria
Tulln, Austria
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Raza A.,University of Natural Resources and Life Sciences, Vienna | Friedel J.K.,University of Natural Resources and Life Sciences, Vienna | Moghaddam A.,Iranian Seed and Plant Improvement Institute | Ardakani M.R.,Islamic Azad University at Karaj | And 3 more authors.
Agricultural Water Management | Year: 2013

Lucerne (Medicago sativa L.) is a perennial legume with high importance as fodder crop under organic farming. Our study analyzes biomass growth and influence on soil water dynamics of three lucerne cultivars in a field experiment and using the simulation model CropSyst. The objective was to evaluate the model for a perennial legume crop, study the relation of cultivar traits with soil water relations and derive a lucerne ideotype for temperate, semi-arid conditions. Two cultivars of European origin (Sitel and Niva) were compared to an Iranian one (Mohajeran). Measurements were made under irrigated (non-water limited) and rain-fed (water limited) conditions. Sitel achieved a cumulative biomass (dry matter yield) of 36.8tha-1 (irrigated) and 25.3tha-1 (rain-fed) over six cuts during the two experimental years, being significantly higher compared to the other cultivars. It was depicted that for Sitel and Mohajeran biomass growth was determined by the ratio of rainfall-to-evapotranspiration. Niva on the contrary exhibited a distinct response of biomass growth to profile water content changes. Also the more even root distribution over the soil profile of Niva indicated an efficient water uptake for this cultivar. CropSyst simulated biomass growth (RMSE 0.58-3.52tha-1) and water content in the soil profile (RMSE 20.9-50.6mm) satisfactorily. Indices of agreement revealed a better model performance for irrigated conditions compared to water-limited growth. Model deviations from measured biomass and profile water content were highest for Mohajeran and it can be attributed to an inadequate distribution of root water extraction over the soil profile in relation to rooting density. Scenario analysis revealed that for the temperate, semi-arid conditions at the site, a maximum root depth between 1.3 and 1.8m is sufficient for optimum growth and water use. Optimization of growth is largely determined by leaf traits such as specific leaf area, but our analysis depicted that in a dry year the sustained water supply via the root system becomes decisive. © 2012 Elsevier B.V.


PubMed | BOKU, AO Research Institute Davos, University of Zürich, Alimentary Health and 2 more.
Type: Journal Article | Journal: Applied and environmental microbiology | Year: 2016

The immune-modulating properties of certain bifidobacterial strains, such as Bifidobacterium longum subsp. longum 35624 (B. longum 35624), have been well described, although the strain-specific molecular characteristics associated with such immune-regulatory activity are not well defined. It has previously been demonstrated that B. longum 35624 produces a cell surface exopolysaccharide (sEPS), and in this study, we investigated the role played by this exopolysaccharide in influencing the host immune response. B. longum 35624 induced relatively low levels of cytokine secretion from human dendritic cells, whereas an isogenic exopolysaccharide-negative mutant derivative (termed sEPSParticular gut commensals, such as B. longum 35624, are known to contribute positively to the development of mucosal immune cells, resulting in protection from inflammatory diseases. However, the molecular basis and mechanisms for these commensal-host interactions are poorly described. In this report, an exopolysaccharide was shown to be decisive in influencing the immune response to the bacterium. We generated an isogenic mutant unable to produce exopolysaccharide and observed that this mutation caused a dramatic change in the response of human immune cells in vitro In addition, the use of mouse models confirmed that lack of exopolysaccharide production induces inflammatory responses to the bacterium. These results implicate the surface-associated exopolysaccharide of the B. longum 35624 cell envelope in the prevention of aberrant inflammatory responses.


Malachova A.,University of Natural Resources and Life Sciences, Vienna | Malachova A.,Mendel University in Brno | Stockova L.,Czech Republic Crop Research Institute | Wakker A.,Ghent University | And 5 more authors.
Analytical and Bioanalytical Chemistry | Year: 2015

A critical assessment of three previously published indirect methods based on acidic hydrolysis using superacids for the determination of “free” and “total” deoxynivalenol (DON) was carried out. The modified mycotoxins DON-3-glucoside (D3G), 3-acetyl-DON (3ADON), and 15-acetyl-DON (15ADON) were chosen as model analytes. The initial experiments focused on the stability/degradation of DON under hydrolytic conditions and the ability to release DON from the modified forms. Acidic conditions that were capable of cleaving D3G, 3ADON, and 15ADON to DON were not found, raising doubts over the efficacy of previously published indirect methods for total DON determination. Validation of these indirect methods for wheat, maize, and barley using UHPLC-MS/MS was performed in order to test the accuracy of the generated results. Validation data for DON, D3G, 3ADON, and 15ADON in nonhydrolyzed and hydrolyzed matrices were obtained. Under the tested conditions, DON was not released from D3G, 3ADON, or 15ADON after hydrolysis and thus none of the published methods were able to cleave the modified forms of DON. In addition to acids, alkaline hydrolysis with KOH for an extended time and at elevated temperatures was also tested. 3ADON and 15ADON were cleaved under the alkaline pH caused by the addition of KOH or aqueous K2CO3 to “neutralize” the acidic sample extracts in the published studies. The published additional DON increase after hydrolysis may have been caused by huge differences in matrix effects and the recovery of DON in nonhydrolyzed and hydrolyzed matrices as well as by the alkaline cleavage of 3ADON or 15ADON after the neutralization of hydrolyzed extracts. © 2015 The Author(s)


Khayatzadeh N.,BOKU | Meszaros G.,BOKU | Gredler B.,Qualitas AG | Schnyder U.,Qualitas AG | And 2 more authors.
Poljoprivreda | Year: 2015

In this study we estimated levels of local ancestry for individuals of the Swiss Fleckvieh dairy cattle population. It is a composite breed descending from two pure breeds, Simmental (SIM) and Red Holstein Friesian (RHF). Illumina BovineSNP50 Beadchip genotyping data for a total of 500 pure and admixed animals were used for the analysis. The global ancestries estimated by Hidden Markov model were 0.68 and 0.32 for RHF and SIM respectively. Local ancestry levels investigated along chromosomes 2, 3 and 13 indicated that there were some regions across the chromosomes exhibiting substantial fluctuations in admixture. On chromosome 2, in the range of 28 to 31, 41 to 46 and 54 to 56 Mb RHF ancestry is substantially higher than average (0.77-0.78). These regions on chromosome 2 are wide, indicating recent admixture. Along the segments on chromosome 2, many QTLs related to dairy, conformation, reproduction, health and carcass traits were found. We observed sharper excess in favour of SIM on chromosome 3, whereas different regions with excess of RHF and SIM were found out on Chromosome 13. At the first part of chromosome 13, an excess of RHF was observed. Moreover, in regions between 40 and 57 Mb excess of SIM, referred to recent admixture was detected. In respect of RHF chromosome segments in admixed animals, dairy, reproduction and health QTLs were found. In positions where more Simmental segments were detected, QTLs related to meat and carcass traits as well as udder health traits were found. In conclusion, the authors believe that estimation of local admixture levels in crossbred populations can add information to the composite breeds history of selection. © 2015, Faculty of Agriculture in Osijek. All rights reserved.


Gindl-Altmutter W.,BOKU | Keckes J.,Austrian Academy of Sciences
BioResources | Year: 2012

The mechanical properties and structure of cactus Opuntia ficus-indica spines were characterised in bending and by means of x-ray diffraction. Using spruce wood cell walls for reference, the modulus of elasticity of Opuntia cactus spines was high in absolute terms, but comparable when specific values were considered, which can be explained by similarities in the cell wall structure of both materials. Differently from the modulus of elasticity, the bending strength of cactus spines was unexpectedly high both in absolute and in specific terms. The unique cellulose-arabinan composite structure of cactus spines, together with high cellulose crystallinity, may explain this finding.


Tan T.-C.,Albanova University Center | Tan T.-C.,Karolinska Institutet | Pitsawong W.,Mahidol University | Wongnate T.,Mahidol University | And 5 more authors.
Journal of Molecular Biology | Year: 2010

Flavoenzymes perform a wide range of redox reactions in nature, and a subclass of flavoenzymes carry covalently bound cofactor. The enzyme-flavin bond helps to increase the flavin's redox potential to facilitate substrate oxidation in several oxidases. The formation of the enzyme-flavin covalent bond-the flavinylation reaction-has been studied for the past 40 years. For the most advocated mechanism of autocatalytic flavinylation, the quinone methide mechanism, appropriate stabilization of developing negative charges at the flavin N(1) and N(5) loci is crucial. Whereas the structural basis for stabilization at N(1) is relatively well studied, the structural requisites for charge stabilization at N(5) remain less clear. Here, we show that flavinylation of histidine 167 of pyranose 2-oxidase from Trametes multicolor requires hydrogen bonding at the flavin N(5)/O(4) locus, which is offered by the side chain of Thr169 when the enzyme is in its closed, but not open, state. Moreover, our data show that additional stabilization at N(5) by histidine 548 is required to ensure high occupancy of the histidyl-flavin bond. The combination of structural and spectral data on pyranose 2-oxidase mutants supports the quinone methide mechanism. Our results demonstrate an elaborate structural fine-tuning of the active site to complete its own formation that couples efficient holoenzyme synthesis to conformational substates of the substrate-recognition loop and concerted movements of side chains near the flavinylation ligand. © 2010 Elsevier Ltd.


Haile A.,ICARDA | Mirkena T.,ILRI | Duguma G.,ILRI | Wurzinger M.,BOKU | And 4 more authors.
Livestock Research for Rural Development | Year: 2013

A study was undertaken to understand local knowledge and practices of communities in animal management as a step in designing and implementation of community-based breeding programs for four local breeds (Afar, Bonga, Horro and Menz) in four sites in Ethiopia. Workshops were held with the project communities to learn their animal management practices, among others the selection of rams and ewes, ram sharing and grazing management. Breeding management skills were studied by conducting heritability and genetic correlation exercises. The most important animal traits for the different production systems were identified from a systems study. Phenotypic, production, and reproduction traits were used either in the form of drawings or verbal explanations. Pair-wise combinations of the traits were presented to the communities to express their choices via voting. For evaluating heritability, the communities were asked which trait pair is relatively more heritable than the other. For the correlation exercise, the communities were asked to estimate the magnitude (high, low, and none) of relationship between the traits in each pair. The results indicate that farmers and pastoralists have good skills in sheep management. Although the mating system is generally uncontrolled, the farmers have a tradition of exchanging of rams. All farmers/pastoralists exercise ewe and ram selection based on phenotypic appearance and recalled pedigree. Their knowledge on heritability of traits and genetic correlations between traits more or less concurs with scientific evidence in literature. For example, qualitative traits (like colour) were judged highly heritable followed by production traits. Knowledge of correlations is used for indirect selection when the target traits are either impossible to assess on the live animal or are sex-limited. Indigenous knowledge and existing practices in the communities, developed through years of practical experience, provide an excellent basis for designing sheep breeding programs.


Nathanail A.V.,Finnish Food Safety Authority | Varga E.,University of Natural Resources and Life Sciences, Vienna | Meng-Reiterer J.,University of Natural Resources and Life Sciences, Vienna | Meng-Reiterer J.,Institute for Biotechnology in Plant Production | And 10 more authors.
Journal of Agricultural and Food Chemistry | Year: 2015

To investigate the metabolic fate of HT-2 toxin (HT2) and T-2 toxin (T2) in wheat (Triticum aestivum L.), an untargeted metabolomics study utilizing stable isotopic labeling and liquid chromatography-high resolution mass spectrometry was performed. In total, 11 HT2 and 12 T2 derived in planta biotransformation products were annotated putatively. In addition to previously reported mono- and diglucosylated forms of HT2, evidence for the formation of HT2-malonyl-glucoside and feruloyl-T2, as well as acetylation and deacetylation products in wheat was obtained for the first time. To monitor the kinetics of metabolite formation, a time course experiment was conducted involving the Fusarium head blight susceptible variety Remus and the resistant cultivar CM-82036. Biotransformation reactions were observed already at the earliest tested time point (6 h after treatment), and formed metabolites showed different kinetic profiles. After ripening, less than 15% of the toxins added to the plants were determined to be unmetabolized. © 2015 American Chemical Society.


PubMed | BOKU, University of Natural Resources and Life Sciences, Vienna, Finnish Food Safety Authority, Institute for Biotechnology in Plant Production and 2 more.
Type: Journal Article | Journal: Journal of agricultural and food chemistry | Year: 2015

To investigate the metabolic fate of HT-2 toxin (HT2) and T-2 toxin (T2) in wheat (Triticum aestivum L.), an untargeted metabolomics study utilizing stable isotopic labeling and liquid chromatography-high resolution mass spectrometry was performed. In total, 11 HT2 and 12 T2 derived in planta biotransformation products were annotated putatively. In addition to previously reported mono- and diglucosylated forms of HT2, evidence for the formation of HT2-malonyl-glucoside and feruloyl-T2, as well as acetylation and deacetylation products in wheat was obtained for the first time. To monitor the kinetics of metabolite formation, a time course experiment was conducted involving the Fusarium head blight susceptible variety Remus and the resistant cultivar CM-82036. Biotransformation reactions were observed already at the earliest tested time point (6 h after treatment), and formed metabolites showed different kinetic profiles. After ripening, less than 15% of the toxins added to the plants were determined to be unmetabolized.


PubMed | BOKU, University of Natural Resources and Life Sciences, Vienna, Finnish Food Safety Authority, Institute for Biotechnology in Plant Production and 2 more.
Type: Journal Article | Journal: Analytical and bioanalytical chemistry | Year: 2015

An extensive study of the metabolism of the type A trichothecene mycotoxins HT-2 toxin and T-2 toxin in barley using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) is reported. A recently developed untargeted approach based on stable isotopic labelling, LC-Orbitrap-MS analysis with fast polarity switching and data processing by MetExtract software was combined with targeted LC-Q-TOF-MS(/MS) analysis for metabolite structure elucidation and quantification. In total, 9 HT-2 toxin and 13 T-2 toxin metabolites plus tentative isomers were detected, which were successfully annotated by calculation of elemental formulas and further LC-HRMS/MS measurements as well as partly identified with authentic standards. As a result, glucosylated forms of the toxins, malonylglucosides, and acetyl and feruloyl conjugates were elucidated. Additionally, time courses of metabolite formation and mass balances were established. For absolute quantification of those compounds for which standards were available, the method was validated by determining apparent recovery, signal suppression, or enhancement and extraction recovery. Most importantly, T-2 toxin was rapidly metabolised to HT-2 toxin and for both parent toxins HT-2 toxin-3-O--glucoside was identified (confirmed by authentic standard) as the main metabolite, which reached its maximum already 1day after toxin treatment. Graphical Abstract Isotope-assisted untargeted screening of HT-2 toxin and T-2 toxin metabolites in barley.

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