@article{ZabalzavanDongenFroehlichetal.2009,
  author    = {Zabalza, Ana and van Dongen, Joost T. and Fr{\"o}hlich, Anja and Oliver, Sandra N. and Faix, Benjamin and Gupta, Kapuganti Jagadis and Schmalzlin, Elmar and Igal, Maria and Orcaray, Luis and Royuela, Mercedes and Geigenberger, Peter},
  title     = {Regulation of respiration and fermentation to control the plant internal oxygen concentration},
  issn      = {0032-0889},
  doi       = {10.1104/pp.108.129288},
  year      = {2009},
  abstract  = {Plant internal oxygen concentrations can drop well below ambient even when the plant grows under optimal conditions. Using pea (Pisum sativum) roots, we show how amenable respiration adapts to hypoxia to save oxygen when the oxygen availability decreases. The data cannot simply be explained by oxygen being limiting as substrate but indicate the existence of a regulatory mechanism, because the oxygen concentration at which the adaptive response is initiated is independent of the actual respiratory rate. Two phases can be discerned during the adaptive reaction: an initial linear decline of respiration is followed by a nonlinear inhibition in which the respiratory rate decreased progressively faster upon decreasing oxygen availability. In contrast to the cytochrome c pathway, the inhibition of the alternative oxidase pathway shows only the linear component of the adaptive response. Feeding pyruvate to the roots led to an increase of the oxygen consumption rate, which ultimately led to anoxia. The importance of balancing the in vivo pyruvate availability in the tissue was further investigated. Using various alcohol dehydrogenase knockout lines of Arabidopsis (Arabidopsis thaliana), it was shown that even under aerobic conditions, alcohol fermentation plays an important role in the control of the level of pyruvate in the tissue. Interestingly, alcohol fermentation appeared to be primarily induced by a drop in the energy status of the tissue rather than by a low oxygen concentration, indicating that sensing the energy status is an important component of optimizing plant metabolism to changes in the oxygen availability.},
  language  = {en}
}
@article{GossnerLewinsohnKahletal.2016,
  author    = {Gossner, Martin M. and Lewinsohn, Thomas M. and Kahl, Tiemo and Grassein, Fabrice and Boch, Steffen and Prati, Daniel and Birkhofer, Klaus and Renner, Swen C. and Sikorski, Johannes and Wubet, Tesfaye and Arndt, Hartmut and Baumgartner, Vanessa and Blaser, Stefan and Bl{\"u}thgen, Nico and B{\"o}rschig, Carmen and Buscot, Francois and Diek{\"o}tter, Tim and Jorge, Leonardo Re and Jung, Kirsten and Keyel, Alexander C. and Klein, Alexandra-Maria and Klemmer, Sandra and Krauss, Jochen and Lange, Markus and M{\"u}ller, J{\"o}rg and Overmann, J{\"o}rg and Pasalic, Esther and Penone, Caterina and Perovic, David J. and Purschke, Oliver and Schall, Peter and Socher, Stephanie A. and Sonnemann, Ilja and Tschapka, Marco and Tscharntke, Teja and T{\"u}rke, Manfred and Venter, Paul Christiaan and Weiner, Christiane N. and Werner, Michael and Wolters, Volkmar and Wurst, Susanne and Westphal, Catrin and Fischer, Markus and Weisser, Wolfgang W. and Allan, Eric},
  title     = {Land-use intensification causes multitrophic homogenization of grassland communities},
  series = {Nature : the international weekly journal of science},
  volume    = {540},
  journal   = {Nature : the international weekly journal of science},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {0028-0836},
  doi       = {10.1038/nature20575},
  pages     = {266 -- +},
  year      = {2016},
  abstract  = {Land-use intensification is a major driver of biodiversity loss(1,2). Alongside reductions in local species diversity, biotic homogenization at larger spatial scales is of great concern for conservation. Biotic homogenization means a decrease in beta-diversity (the compositional dissimilarity between sites). Most studies have investigated losses in local (alpha)-diversity(1,3) and neglected biodiversity loss at larger spatial scales. Studies addressing beta-diversity have focused on single or a few organism groups (for example, ref. 4), and it is thus unknown whether land-use intensification homogenizes communities at different trophic levels, above-and belowground. Here we show that even moderate increases in local land-use intensity (LUI) cause biotic homogenization across microbial, plant and animal groups, both above- and belowground, and that this is largely independent of changes in alpha-diversity. We analysed a unique grassland biodiversity dataset, with abundances of more than 4,000 species belonging to 12 trophic groups. LUI, and, in particular, high mowing intensity, had consistent effects on beta-diversity across groups, causing a homogenization of soil microbial, fungal pathogen, plant and arthropod communities. These effects were nonlinear and the strongest declines in beta-diversity occurred in the transition from extensively managed to intermediate intensity grassland. LUI tended to reduce local alpha-diversity in aboveground groups, whereas the alpha-diversity increased in belowground groups. Correlations between the alpha-diversity of different groups, particularly between plants and their consumers, became weaker at high LUI. This suggests a loss of specialist species and is further evidence for biotic homogenization. The consistently negative effects of LUI on landscape-scale biodiversity underscore the high value of extensively managed grasslands for conserving multitrophic biodiversity and ecosystem service provision. Indeed, biotic homogenization rather than local diversity loss could prove to be the most substantial consequence of land-use intensification.},
  language  = {en}
}
@article{OliverLunnUrbanczykWochniaketal.2008,
  author    = {Oliver, Sandra N. and Lunn, John Edward and Urbanczyk-Wochniak, Ewa and Lytovchenko, Anna and van Dongen, Joost T. and Faix, Benjamin and Schm{\"a}lzlin, Elmar and Fernie, Alisdair and Schm{\"a}elzlin, E. and Geigenberger, Peter},
  title     = {Decreased expression of cytosolic pyruvate kinase in potato tubers leads to a decline in pyruvate resulting in an in vivo repression of the alternative oxidase},
  doi       = {10.1104/pp.108.126516},
  year      = {2008},
  abstract  = {The aim of this work was to investigate the effect of decreased cytosolic pyruvate kinase (PKc) on potato (Solanum tuberosum) tuber metabolism. Transgenic potato plants with strongly reduced levels of PKc were generated by RNA interference gene silencing under the control of a tuber-specific promoter. Metabolite profiling showed that decreased PKc activity led to a decrease in the levels of pyruvate and some other organic acids involved in the tricarboxylic acid cycle. Flux analysis showed that this was accompanied by changes in carbon partitioning, with carbon flux being diverted from glycolysis toward starch synthesis. However, this metabolic shift was relatively small and hence did not result in enhanced starch levels in the tubers. Although total respiration rates and the ATP to ADP ratio were largely unchanged, transgenic tubers showed a strong decrease in the levels of alternative oxidase (AOX) protein and a corresponding decrease in the capacity of the alternative pathway of respiration. External feeding of pyruvate to tuber tissue or isolated mitochondria resulted in activation of the AOX pathway, both in the wild type and the PKc transgenic lines, providing direct evidence for the regulation of AOX by changes in pyruvate levels. Overall, these results provide evidence for a crucial role of PKc in the regulation of pyruvate levels as well as the level of the AOX in heterotrophic plant tissue, and furthermore reveal that these parameters are interlinked in vivo.},
  language  = {en}
}