@article{GuerreroRamirezCravenReichetal.2017, author = {Guerrero-Ramirez, Nathaly Rokssana and Craven, Dylan and Reich, Peter B. and Ewel, John J. and Isbell, Forest and Koricheva, Julia and Parrotta, John A. and Auge, Harald and Erickson, Heather E. and Forrester, David I. and Hector, Andy and Joshi, Jasmin Radha and Montagnini, Florencia and Palmborg, Cecilia and Piotto, Daniel and Potvin, Catherine and Roscher, Christiane and van Ruijven, Jasper and Tilman, David and Wilsey, Brian and Eisenhauer, Nico}, title = {Diversity-dependent temporal divergence of ecosystem functioning in experimental ecosystems}, series = {Nature ecology \& evolution}, volume = {1}, journal = {Nature ecology \& evolution}, number = {11}, publisher = {Nature Publ. Group}, address = {London}, issn = {2397-334X}, doi = {10.1038/s41559-017-0325-1}, pages = {1639 -- 1642}, year = {2017}, abstract = {The effects of biodiversity on ecosystem functioning generally increase over time, but the underlying processes remain unclear. Using 26 long-term grassland and forest experimental ecosystems, we demonstrate that biodiversity-ecosystem functioning relationships strengthen mainly by greater increases in functioning in high-diversity communities in grasslands and forests. In grasslands, biodiversity effects also strengthen due to decreases in functioning in low-diversity communities. Contrasting trends across grasslands are associated with differences in soil characteristics.}, language = {en} } @article{BerryRosaHowardetal.2017, author = {Berry, Scott and Rosa, Stefanie and Howard, Martin and Buhler, Marc and Dean, Caroline}, title = {Disruption of an RNA-binding hinge region abolishes LHP1-mediated epigenetic repression}, series = {Genes \& Development}, volume = {31}, journal = {Genes \& Development}, publisher = {Cold Spring Harbor Laboratory Press}, address = {Cold Spring Harbor, NY}, issn = {0890-9369}, doi = {10.1101/gad.305227.117}, pages = {2115 -- 2120}, year = {2017}, abstract = {Epigenetic maintenance of gene repression is essential for development. Polycomb complexes are central to this memory, but many aspects of the underlying mechanism remain unclear. LIKE HETEROCHROMATIN PROTEIN 1 (LHP1) binds Polycomb-deposited H3K27me3 and is required for repression of many Polycomb target genes in Arabidopsis. Here we show that LHP1 binds RNA in vitro through the intrinsically disordered hinge region. By independently perturbing the RNA-binding hinge region and H3K27me3 (trimethylation of histone H3 at Lys27) recognition, we found that both facilitate LHP1 localization and H3K27me3 maintenance. Disruption of the RNAbinding hinge region also prevented formation of subnuclear foci, structures potentially important for epigenetic repression.}, language = {en} } @article{FerTietjenJeltschetal.2017, author = {Fer, Istem and Tietjen, Britta and Jeltsch, Florian and Wolff, Christian Michael}, title = {The influence of El Nino-Southern Oscillation regimes on eastern African vegetation and its future implications under the RCP8.5 warming scenario}, series = {Biogeosciences}, volume = {14}, journal = {Biogeosciences}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1726-4170}, doi = {10.5194/bg-14-4355-2017}, pages = {4355 -- 4374}, year = {2017}, abstract = {The El Nino-Southern Oscillation (ENSO) is the main driver of the interannual variability in eastern African rainfall, with a significant impact on vegetation and agriculture and dire consequences for food and social security. In this study, we identify and quantify the ENSO contribution to the eastern African rainfall variability to forecast future eastern African vegetation response to rainfall variability related to a predicted intensified ENSO. To differentiate the vegetation variability due to ENSO, we removed the ENSO signal from the climate data using empirical orthogonal teleconnection (EOT) analysis. Then, we simulated the ecosystem carbon and water fluxes under the historical climate without components related to ENSO teleconnections. We found ENSO-driven patterns in vegetation response and confirmed that EOT analysis can successfully produce coupled tropical Pacific sea surface temperature-eastern African rainfall teleconnection from observed datasets. We further simulated eastern African vegetation response under future climate change as it is projected by climate models and under future climate change combined with a predicted increased ENSO intensity. Our EOT analysis highlights that climate simulations are still not good at capturing rainfall variability due to ENSO, and as we show here the future vegetation would be different from what is simulated under these climate model outputs lacking accurate ENSO contribution. We simulated considerable differences in eastern African vegetation growth under the influence of an intensified ENSO regime which will bring further environmental stress to a region with a reduced capacity to adapt effects of global climate change and food security.}, language = {en} } @article{MajdaGronesSintornetal.2017, author = {Majda, Mateusz and Grones, Peter and Sintorn, Ida-Maria and Vain, Thomas and Milani, Pascale and Krupinski, Pawel and Zagorska-Marek, Beata and Viotti, Corrado and Jonsson, Henrik and Mellerowicz, Ewa J. and Hamant, Olivier and Robert, Stephanie}, title = {Mechanochemical Polarization of Contiguous Cell Walls Shapes Plant Pavement Cells}, series = {Developmental cell}, volume = {43}, journal = {Developmental cell}, publisher = {Cell Press}, address = {Cambridge}, issn = {1534-5807}, doi = {10.1016/j.devcel.2017.10.017}, pages = {290 -- +}, year = {2017}, abstract = {The epidermis of aerial plant organs is thought to be limiting for growth, because it acts as a continuous load-bearing layer, resisting tension. Leaf epidermis contains jigsaw puzzle piece-shaped pavement cells whose shape has been proposed to be a result of subcellular variations in expansion rate that induce local buckling events. Paradoxically, such local compressive buckling should not occur given the tensile stresses across the epidermis. Using computational modeling, we show that the simplest scenario to explain pavement cell shapes within an epidermis under tension must involve mechanical wall heterogeneities across and along the anticlinal pavement cell walls between adjacent cells. Combining genetics, atomic force microscopy, and immunolabeling, we demonstrate that contiguous cell walls indeed exhibit hybrid mechanochemical properties. Such biochemical wall heterogeneities precede wall bending. Altogether, this provides a possible mechanism for the generation of complex plant cell shapes.}, language = {en} } @article{KurzeHeinkenFartmann2017, author = {Kurze, Susanne and Heinken, Thilo and Fartmann, Thomas}, title = {Nitrogen enrichment of host plants has mostly beneficial effects on the life-history traits of nettle-feeding butterflies}, series = {Acta oecologica : international journal of ecology}, volume = {85}, journal = {Acta oecologica : international journal of ecology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1146-609X}, doi = {10.1016/j.actao.2017.11.005}, pages = {157 -- 164}, year = {2017}, abstract = {Butterflies rank among the most threatened animal groups throughout Europe. However, current population trends differ among species. The nettle-feeding butterflies Aglais io and Aglais urticae cope successfully with the anthropogenic land-use change. Both species are assumed to be pre-adapted to higher nitrogen contents in their host plant, stinging nettle (Urtica dioica). However, it is currently unknown, whether this pre-adaptation enables both Aglais species to cope successfully or even to benefit from the excessive nitrogen availabilities in nettles growing in modern farmlands. For this reason, this study focused on the response of both Aglais species to unfertilized nettles compared to nettles receiving 150 or 300 kg N ha(-1) yr(-1) (i.e., common fertilizer quantities of modern-day agriculture). Fertilized nettles were characterized by higher nitrogen concentrations and lower C:N ratios compared to the control group. In both Aglais species, the individuals feeding on fertilized nettles had higher survival rates, shorter larval periods and heavier pupae and, in A. urticae also longer forewings. All these trait shifts are beneficial for the individuals, lowering their risk to die before reproduction and increasing their reproductive potential. These responses agree with the well-accepted nitrogen-limitation hypothesis predicting a positive relationship between the nitrogen content of the diet and the performance of herbivorous insects. Furthermore, our findings suggest that the increasing abundance of both Aglais species may result not only from the increasing spread of nettles into the farmland but also from changes in their quality due to the eutrophication of the landscape during recent decades.}, language = {en} } @article{DennisPatelOliveretal.2017, author = {Dennis, Alice B. and Patel, Vilas and Oliver, Kerry M. and Vorburger, Christoph}, title = {Parasitoid gene expression changes after adaptation to symbiont-protected hosts}, series = {Evolution}, volume = {71}, journal = {Evolution}, publisher = {Wiley}, address = {Hoboken}, issn = {0014-3820}, doi = {10.1111/evo.13333}, pages = {2599 -- 2617}, year = {2017}, abstract = {Reciprocal selection between aphids, their protective endosymbionts, and the parasitoid wasps that prey upon them offers an opportunity to study the basis of their coevolution. We investigated adaptation to symbiont\&\#8208;conferred defense by rearing the parasitoid wasp Lysiphlebus fabarum on aphids (Aphis fabae) possessing different defensive symbiont strains (Hamiltonella defensa). After ten generations of experimental evolution, wasps showed increased abilities to parasitize aphids possessing the H. defensa strain they evolved with, but not aphids possessing the other strain. We show that the two symbiont strains encode different toxins, potentially creating different targets for counter\&\#8208;adaptation. Phenotypic and behavioral comparisons suggest that neither life\&\#8208;history traits nor oviposition behavior differed among evolved parasitoid lineages. In contrast, comparative transcriptomics of adult female wasps identified a suite of differentially expressed genes among lineages, even when reared in a common, symbiont\&\#8208;free, aphid host. In concurrence with the specificity of each parasitoid lineages' infectivity, most differentially expressed parasitoid transcripts were also lineage\&\#8208;specific. These transcripts are enriched with putative venom toxins and contain highly expressed, potentially defensive viral particles. Together, these results suggest that wild populations of L. fabarum employ a complicated offensive arsenal with sufficient genetic variation for wasps to adapt rapidly and specifically to their hosts' microbial defenses.}, language = {en} } @article{MaoAryalLangeneckeretal.2017, author = {Mao, Hailiang and Aryal, Bibek and Langenecker, Tobias and Hagmann, Jorg and Geisler, Markus and Grebe, Markus}, title = {Arabidopsis BTB/POZ protein-dependent PENETRATION3 trafficking and disease susceptibility}, series = {Nature plants}, volume = {3}, journal = {Nature plants}, publisher = {Nature Publ. Group}, address = {London}, issn = {2055-026X}, doi = {10.1038/s41477-017-0039-z}, pages = {854 -- 858}, year = {2017}, abstract = {The outermost cell layer of plant roots (epidermis) constantly encounters environmental challenges. The epidermal outer plasma membrane domain harbours the PENETRATION3 (PEN3)/ABCG36/PDR8 ATP-binding cassette transporter that confers non-host resistance to several pathogens. Here, we show that the Arabidopsis ENDOPLASMIC RETICULUM-ARRESTED PEN3 (EAP3) BTB/POZ-domain protein specifically mediates PEN3 exit from the endoplasmic reticulum and confers resistance to a root-penetrating fungus, providing prime evidence for BTB/POZ-domain protein-dependent membrane trafficking underlying disease resistance.}, language = {en} } @article{RomeroDiazBreedveldFitze2017, author = {Romero-Diaz, Cristina and Breedveld, Merel Cathelijne and Fitze, Patrick S.}, title = {Climate Effects on Growth, Body Condition, and Survival Depend on the Genetic Characteristics of the Population}, series = {The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences}, volume = {190}, journal = {The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences}, publisher = {Univ. of Chicago Press}, address = {Chicago}, issn = {0003-0147}, doi = {10.1086/693780}, pages = {649 -- 662}, year = {2017}, abstract = {Climatic change is expected to affect individual life histories and population dynamics, potentially increasing vulnerability to extinction. The importance of genetic diversity has been highlighted for adaptation and population persistence. However, whether responses of life-history traits to a given environmental condition depend on the genetic characteristics of a population remains elusive. Here we tested this hypothesis in the lizard Zootoca vivipara by simultaneously manipulating habitat humidity, a major climatic predictor of Zootoca's distribution, and adult male color morph frequency, a trait with genome-wide linkage. Interactive effects of humidity and morph frequency had immediate effects on growth and body condition of juveniles and yearlings, as well as on adult survival, and delayed effects on offspring size. In yearlings, higher humidity led to larger female body size and lower humidity led to higher male compared to female survival. In juveniles and yearlings, some treatment effects were compensated over time. The results show that individual responses to environmental conditions depend on the population's color morph frequency, age class, and sex and that these affect intra- and inter-age class competition. Moreover, humidity affected the competitive environment rather than imposing trait-based selection on specific color morphs. This indicates that species' responses to changing environments (e.g., to climate change) are highly complex and difficult to accurately reconstruct and predict without information on the genetic characteristics and demographic structure of populations.}, language = {en} } @article{FlaschvonElmWester2017, author = {Flasch, Leopold and von Elm, Natalie and Wester, Petra}, title = {Nectar-drinking Elephantulus edwardii as a potential pollinator of Massonia echinata, endemic to the Bokkeveld plateau in South Africa}, series = {African journal of ecology}, volume = {55}, journal = {African journal of ecology}, publisher = {Wiley}, address = {Hoboken}, issn = {0141-6707}, doi = {10.1111/aje.12352}, pages = {376 -- 379}, year = {2017}, language = {en} } @article{ThammSchollReimetal.2017, author = {Thamm, Markus and Scholl, Christina and Reim, Tina and Gruebel, Kornelia and Moeller, Karin and Rossler, Wolfgang and Scheiner, Ricarda}, title = {Neuronal distribution of tyramine and the tyramine receptor AmTAR1 in the honeybee brain}, series = {The journal of comparative neurology}, volume = {525}, journal = {The journal of comparative neurology}, publisher = {Wiley}, address = {Hoboken}, issn = {0021-9967}, doi = {10.1002/cne.24228}, pages = {2615 -- 2631}, year = {2017}, abstract = {Tyramine is an important neurotransmitter, neuromodulator, and neurohormone in insects. In honeybees, it is assumed to have functions in modulating sensory responsiveness and controlling motor behavior. Tyramine can bind to two characterized receptors in honeybees, both of which are coupled to intracellular cAMP pathways. How tyramine acts on neuronal, cellular and circuit levels is unclear. We investigated the spatial brain expression of the tyramine receptor AmTAR1 using a specific antibody. This antibody detects a membrane protein of the expected molecular weight in western blot analysis. In honeybee brains, it labels different structures which process sensory information. Labeling along the antennal nerve, in projections of the dorsal lobe and in the gnathal ganglion suggest that tyramine receptors are involved in modulating gustatory and tactile perception. Furthermore, the ellipsoid body of the central complex and giant synapses in the lateral complex show AmTAR1-like immunoreactivity (AmTAR1-IR), suggesting a role of this receptor in modulating sky-compass information and/or higher sensor-motor control. Additionally, intense signals derive from the mushroom bodies, higher-order integration centers for olfactory, visual, gustatory and tactile information. To investigate whether AmTAR1-expressing brain structures are in vicinity to tyramine releasing sites, a specific tyramine antibody was applied. Tyramine-like labeling was observed in AmTAR1-IR positive structures, although it was sometimes weak and we did not always find a direct match of ligand and receptor. Moreover, tyramine-like immunoreactivity was also found in brain regions without AmTAR1-IR (optic lobes, antennal lobes), indicating that other tyramine-specific receptors may be expressed there.}, language = {en} }