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Marburg an der Lahn, Germany

Schweiger R.,Bielefeld University | Baier M.C.,Bielefeld University | Persicke M.,Universitatsstrasse 27 | Muller C.,Bielefeld University
Nature Communications | Year: 2014

The chemical composition of plants (phytometabolome) is dynamic and modified by environmental factors. Understanding its modulation allows to improve crop quality and decode mechanisms underlying plant-pest interactions. Many studies that investigate metabolic responses to the environment focus on single model species and/or few target metabolites. However, comparative studies using environmental metabolomics are needed to evaluate commonalities of chemical responses to certain challenges. We assessed the specificity of foliar metabolic responses of five plant species to the widespread, ancient symbiosis with a generalist arbuscular mycorrhizal fungus. Here we show that plant species share a large core metabolomea but nevertheless the phytometabolomes are modulated highly species/taxon-specifically. Such a low conservation of responses across species highlights the importance to consider plant metabolic prerequisites and the long time of specific plant-fungus coevolution. Thus, the transferability of findings regarding phytometabolome modulation by an identical AM symbiont is severely limited even between closely related species. © 2014 Macmillan Publishers Limited. All rights reserved. Source


Albohn-Kuhne C.,Universitatsstrasse 27 | Rief W.,University of Marburg
PPmP Psychotherapie Psychosomatik Medizinische Psychologie | Year: 2011

Binge-eating disorder (BED) is the most common eating disorder found in obese people. The present study compared 89 obese participants with and without BED in terms of eating-, weight- and body related shame and guilt and their associaton to self-eestem and social anxiety. The results illustrated that obese people with BED reported higher scores in disorder specific shame and guilt, except feeling shame about their weight and their body; they suffered from lower self-esteem than obese without BED. The results confirmed that self-esteem is a significant statistical predictor of feeling shame. Futhermore obese with BED suffered from social phobia more frequently. The results emphasized the need to consider feelings of shame and guilt and the importance of social anxiety in prevention and therapy of obesity. © Georg Thieme Verlag KG Stuttgart New York. Source


Pankoke H.,Bielefeld University | Pankoke H.,Universitatsstrasse 27 | Buschmann T.,Bielefeld University | Muller C.,Bielefeld University | Muller C.,Universitatsstrasse 27
Phytochemistry | Year: 2013

The typical defense compounds of Plantaginaceae are the iridoid glycosides, which retard growth and/or enhance mortality of non-adapted herbivores. In plants, glycosidic defense compounds and hydrolytic enzymes often form a dual defense system, in which the glycosides are activated by the enzymes to exert biological effects. Yet, little is known about the activating enzymes in iridoid glycoside-containing plants. To examine the role of plant-derived β-glucosidases in the dual defense system of two common plantain species, Plantago lanceolata and Plantago major, we determined the concentration of iridoid glycosides as well as the β-glucosidase activity in leaves of different age. To investigate the presence of other leaf metabolites potentially involved in plant defense, we used a metabolic fingerprinting approach with ultra-high performance liquid chromatography coupled with time-of-flight-mass spectrometry. According to the optimal defense hypothesis, more valuable parts such as young leaves should be better protected than less valuable parts. Therefore, we expected that both, the concentrations of defense compounds as well as the β-glucosidase activity, should be highest in younger leaves and decrease with increasing leaf age. Both species possessed β-glucosidase activity, which hydrolyzed aucubin, one of the two most abundant iridoid glycosides in both plant species, with high activity. In line with the optimal defense hypothesis, the β-glucosidase activity in both Plantago species as well as the concentration of defense-related metabolites such as iridoid glycosides correlated negatively to leaf age. When leaf extracts were incubated with bovine serum albumin and aucubin, SDS-PAGE revealed a protein-denaturing effect of the leaf extracts of both plantain species, suggesting that iridoid glycosides and plant β-glucosidase interact in a dual defense system. © 2013 Elsevier Ltd. All rights reserved. Source


Sterthoff C.,Universitatsstrasse 27 | Lang A.E.,Albert Ludwigs University of Freiburg | Schwan C.,Albert Ludwigs University of Freiburg | Tauch A.,Universitatsstrasse 27 | Aktories K.,Albert Ludwigs University of Freiburg
Infection and Immunity | Year: 2010

Clostridium botulinum C2 toxin consists of the binding component C2II and the enzyme component C2I, which ADP-ribosylates G-actin of eukaryotic cells. Trypsin-activated C2II (C2IIa) forms heptamers that mediate cell binding and translocation of C2I from acidic endosomes into the cytosol of target cells. By genome sequencing of C. botulinum strain (C) 2300, we found that C2II from this strain carries a C-terminal extension of 129 amino acids, unlike its homologous counterparts from strains (C) 203U28, (C) 468, and (D) 1873. This extension shows a high similarity to the C-terminal receptor-binding domain of C2II and is presumably the result of a duplication of this domain. The C2II extension facilitates the binding to cell surface receptors, which leads to an increased intoxication efficiency compared to that of C2II proteins from other C. botulinum strains. Copyright © 2010, American Society for Microbiology. All Rights Reserved. Source


Pankoke H.,Bielefeld University | Pankoke H.,Universitatsstrasse 27 | Muller C.,Bielefeld University | Muller C.,Universitatsstrasse 27
Plant Physiology and Biochemistry | Year: 2013

After defoliation challenges, plants should invest their resources in a way that maximizes their fitness, which may lead to trade-offs in investment in physiological versus chemical traits. Thereby, the regrowth capacity of plants may highly depend on the type and the severity of defoliation. In the present study, we investigated the phenotypic plasticity of Plantago lanceolata L. in response to different defoliation events in a comprehensive way, measuring various traits. This herbaceous species grows on ruderal sites and typically suffers from repeated substantial losses of shoot biomass due to mowing and/or herbivory during the growing season. To study treatment-specific effects of defoliation on resource allocation and induction of defence responses, plants were exposed either to (repeated) mechanical clipping or to herbivory by the generalist Grammia incorrupta (Lepidoptera). Next to regrowth and physiological leaf traits such as the water content, the specific leaf area and C/N ratios of these plants, primary and secondary metabolites in leaves were analyzed with a metabolite profiling approach using gas chromatography coupled with mass spectrometry. The different defoliation treatments strongly affected the regrowth capacity of clipped and herbivore-treated plants, leading to additive changes in physiological leaf traits. As a response to the defoliation treatments, clipped and herbivore-treated plants reduced mainly carbon-based primary metabolites such as sorbitol, and glucose, suggesting that the different defoliation challenges similarly limited the ability of carbon fixation. Yet, only in response to herbivory but not to clipping, plants induced defence compounds, which indicates the importance of treatment-specific responses despite severe resource limitations. Overall, the different responses to defoliation by clipping and herbivory may reflect allocation constraints and/or adaptive plasticity. © 2013 Elsevier Masson SAS. Source

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