TY - GEN A1 - Eckert, Silvia A1 - Herden, Jasmin A1 - Stift, Marc A1 - Joshi, Jasmin Radha A1 - van Kleunen, Mark T1 - Manipulation of cytosine methylation does not remove latitudinal clines in two invasive goldenrod species in Central Europe T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Invasive species frequently differentiate phenotypically in novel environments within a few generations, often even with limited genetic variation. For the invasive plants Solidago canadensis and S. gigantea, we tested whether such differentiation might have occurred through heritable epigenetic changes in cytosine methylation. In a 2-year common-garden experiment, we grew plants from seeds collected along a latitudinal gradient in their non-native Central European range to test for trait differentiation and whether differentiation disappeared when seeds were treated with the demethylation agent zebularine. Microsatellite markers revealed no population structure along the latitudinal gradient in S. canadensis, but three genetic clusters in S. gigantea. Solidago canadensis showed latitudinal clines in flowering phenology and growth. In S. gigantea, the number of clonal offspring decreased with latitude. Although zebularine had a significant effect on early growth, probably through effects on cytosine methylation, latitudinal clines remained (or even got stronger) in plants raised from seeds treated with zebularine. Thus, our experiment provides no evidence that epigenetic mechanisms by selective cytosine methylation contribute to the observed phenotypic differentiation in invasive goldenrods in Central Europe. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1378 KW - common‐garden experiment KW - epigenetic variation KW - microsatellites KW - Solidago canadensis KW - Solidago gigantea KW - zebularine Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-569528 SN - 1866-8372 IS - 1 ER - TY - GEN A1 - Fichtner, Franziska A1 - Barbier, Francois F. A1 - Annunziata, Maria Grazia A1 - Feil, Regina A1 - Olas, Justyna Jadwiga A1 - Müller-Röber, Bernd A1 - Stitt, Mark A1 - Beveridge, Christine A. A1 - Lunn, John Edward T1 - Regulation of shoot branching in arabidopsis by trehalose 6-phosphate T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Trehalose 6-phosphate (Tre6P) is a sucrose signalling metabolite that has been implicated in regulation of shoot branching, but its precise role is not understood. We expressed tagged forms of TREHALOSE-6-PHOSPHATE SYNTHASE1 (TPS1) to determine where Tre6P is synthesized in arabidopsis (Arabidopsis thaliana), and investigated the impact of localized changes in Tre6P levels, in axillary buds or vascular tissues, on shoot branching in wild-type and branching mutant backgrounds. TPS1 is expressed in axillary buds and the subtending vasculature, as well as in the leaf and stem vasculature. Expression of a heterologous Tre6P phosphatase (TPP) to lower Tre6P in axillary buds strongly delayed bud outgrowth in long days and inhibited branching in short days. TPP expression in the vasculature also delayed lateral bud outgrowth and decreased branching. Increased Tre6P in the vasculature enhanced branching and was accompanied by higher expression of FLOWERING LOCUS T (FT) and upregulation of sucrose transporters. Increased vascular Tre6P levels enhanced branching in branched1 but not in ft mutant backgrounds. These results provide direct genetic evidence of a local role for Tre6P in regulation of axillary bud outgrowth within the buds themselves, and also connect Tre6P with systemic regulation of shoot branching via FT. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1383 KW - Arabidopsis thaliana (arabidopsis) KW - axillary bud KW - branching KW - sucrose KW - sugar signalling KW - trehalose 6‐ phosphate (Tre6P) Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-569564 SN - 1866-8372 IS - 4 ER - TY - GEN A1 - Zaplata, Markus Klemens A1 - Nhabanga, Abel A1 - Stalmans, Marc A1 - Volpers, Thomas A1 - Burkart, Michael A1 - Sperfeld, Erik T1 - Grasses cope with high-contrast ecosystem conditions in the large outflow of the Banhine wetlands, Mozambique T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Ecosystems with highly pulsed water supply must be better understood as climate change may increase frequency and severity of intense storms, droughts and floods. Here we collected data over 3 years (2016-2018) in the episodic wetland outflow channel (Aluize), Banhine National Park, in which the system state changed from dry to wet to dry. Field sampling included vegetation records, small-scale vegetation zoning, the seed bank and water and soil quality. The same main plant species were found in both dry and wet conditions across the riverbed of the outflow channel. We found only very few diaspores of plants in the soil after prolonged drought. In the subsequent flooded state, we examined very dense vegetation on the water surface, which was dominated by the gramineous species Paspalidium obtusifolium. This species formed a compact floating mat that was rooted to the riverbed. The Cyperaceae Bolboschoenus glaucus showed high clonal growth in the form of root tubers, which likely serve as important food reservoir during drought. Soil and water analyses do not indicate a limitation by nutrients. We outline how resident people may change the plant community structure with an increasing practice of setting fire to the meadows in the dried-up riverbed to facilitate plant regrowth as food for their livestock. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1386 KW - Aluize KW - biological soil crusts KW - Changane KW - droughts KW - floating mat KW - flooded grasslands KW - multi‐ year flooding cycle KW - plant clonality KW - seed bank KW - temporary wetland Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-573515 SN - 1866-8372 IS - 1 ER - TY - THES A1 - Stange, Maike T1 - A study on Coronin-A and Aip1 function in motility of Dictyostelium discoideum and on Aip1 interchangeability between Dictyostelium discoideum and Arabidopsis thaliana T1 - Studie über die Funktion von Coronin-A und Aip1 bei der Motilität von Dictyostelium discoideum und zur Aip1-Austauschbarkeit zwischen Dictyostelium discoideum und Arabidopsis thaliana N2 - Actin is one of the most highly conserved proteins in eukaryotes and distinct actin-related proteins with filament-forming properties are even found in prokaryotes. Due to these commonalities, actin-modulating proteins of many species share similar structural properties and proposed functions. The polymerization and depolymerization of actin are critical processes for a cell as they can contribute to shape changes to adapt to its environment and to move and distribute nutrients and cellular components within the cell. However, to what extent functions of actin-binding proteins are conserved between distantly related species, has only been addressed in a few cases. In this work, functions of Coronin-A (CorA) and Actin-interacting protein 1 (Aip1), two proteins involved in actin dynamics, were characterized. In addition, the interchangeability and function of Aip1 were investigated in two phylogenetically distant model organisms. The flowering plant Arabidopsis thaliana (encoding two homologs, AIP1-1 and AIP1-2) and in the amoeba Dictyostelium discoideum (encoding one homolog, DdAip1) were chosen because the functions of their actin cytoskeletons may differ in many aspects. Functional analyses between species were conducted for AIP1 homologs as flowering plants do not harbor a CorA gene. In the first part of the study, the effect of four different mutation methods on the function of Coronin-A protein and the resulting phenotype in D. discoideum was revealed in two genetic knockouts, one RNAi knockdown and a sudden loss-of-function mutant created by chemical-induced dislocation (CID). The advantages and disadvantages of the different mutation methods on the motility, appearance and development of the amoebae were investigated, and the results showed that not all observed properties were affected with the same intensity. Remarkably, a new combination of Selection-Linked Integration and CID could be established. In the second and third parts of the thesis, the exchange of Aip1 between plant and amoeba was carried out. For A. thaliana, the two homologs (AIP1-1 and AIP1-2) were analyzed for functionality as well as in D. discoideum. In the Aip1-deficient amoeba, rescue with AIP1-1 was more effective than with AIP1-2. The main results in the plant showed that in the aip1-2 mutant background, reintroduced AIP1-2 displayed the most efficient rescue and A. thaliana AIP1-1 rescued better than DdAip1. The choice of the tagging site was important for the function of Aip1 as steric hindrance is a problem. The DdAip1 was less effective when tagged at the C-terminus, while the plant AIP1s showed mixed results depending on the tag position. In conclusion, the foreign proteins partially rescued phenotypes of mutant plants and mutant amoebae, despite the organisms only being very distantly related in evolutionary terms. N2 - Actin ist eines der am stärksten konservierten Proteine in Eukaryoten und sogar Prokaryoten weisen Aktin-ähnliche Proteine mit filamentbildenden Eigenschaften auf. Aufgrund dieser Gemeinsamkeiten teilen Aktin-modulierte Proteine vieler Arten ähnliche strukturelle Eigenschaften und vermutlich auch Funktionen. Die Polymerisierung und Depolymerisation von Aktin sind kritische Prozesse für eine Zelle, da sie zu Zellformänderungen beitragen können, um sich an die Umgebung anzupassen und Nährstoffe sowie zelluläre Komponenten innerhalb der Zelle zu bewegen und zu verteilen. Inwieweit die Funktionen von Aktin-bindenden Proteinen zwischen entfernt verwandten Arten funktionell konserviert sind, wurde jedoch nur in wenigen Fällen untersucht. In dieser Arbeit wurden Funktionen von Coronin-A (CorA) und Actin-interagierendem Protein 1 (AIP1), zweier an der Aktindynamik beteiligter Proteine, charakterisiert. Darüber hinaus wurde die Austauschbarkeit und Funktion von AIP1 in zwei phylogenetisch entfernten Modellorganismen untersucht. Die Blütenpflanze Arabidopsis thaliana (kodiert für zwei Homologe: AIP1-1 und AIP1-2) und die Amöbe Dictyostelium discoideum (kodiert für ein Homolog: DdAip1) wurden ausgewählt, weil die Funktionen ihrer Aktin-Zytoskelette in mehreren Aspekten verschieden sein könnten. Funktionelle Analysen zwischen Arten wurden für AIP1-Homologe durchgeführt, da Blütenpflanzen kein CorA Gen tragen. Im ersten Teil der Arbeit wurde die Wirkung von vier verschiedenen Mutationsmethoden auf die Funktion des CorA-Proteins und des resultierenden Phänotyps in D. discoideum in zwei genetischen Knockouts, einem RNAi Knockdown und einem durch chemisch induzierte Delokalisierung (CID) erzeugten Mutanten geprüft. Die Vor- und Nachteile der Methoden zur Motilität, des Aussehens und der Entwicklung der Amöben wurden untersucht. Die Ergebnisse zeigten, dass nicht alle beobachteten Eigenschaften mit der gleichen Intensität beeinflusst wurden. Hierbei wurde eine neue Methodenkombination aus selektionsgebundener Integration und CID etabliert. Im zweiten und im dritten Teil der Arbeit wurde der Austausch von AIP1 zwischen Pflanze und Amöben durchgeführt. Die zwei A. thaliana-Homologe AIP1-1 und AIP1-2 wurden auf Funktionalität in D. discoideum geprüft. In Aip1-defizienten Amöben war die Rettung mit AIP1-1 effektiver als bei AIP1-2. Die Hauptergebnisse der Arbeit wiesen darauf hin, dass AIP1-2 im aip1.2-1 act7 Mutantenhintergrund die effizienteste Rettung zeigte, während A. thaliana AIP1-1 effizienter rettete als DdAip1. Die Auswahl der Tagging-Site war für die AIP1-Funktion bedeutend, da sterische Hinderung eine Rolle spielen könnte. DdAip1 war weniger effektiv, wenn es am C-Terminus fusioniert war, während die Proteinfusionen der A. thaliana AIP1s je nach Position der „tags“ unterschiedliche Ergebnisse zeigten. Zusammenfassend retteten die fremden Proteine teilweise Phänotypen von mutierten Pflanzen und mutierten Amöben, obwohl die Organismen evolutionär weit entfernt verwandt sind. KW - actin KW - cell motility KW - plant growth KW - selection-linked integration KW - chemically induced dislocation KW - interspecies interchange KW - Aktin KW - Zellmotilität KW - Pflanzenwachstum KW - Selection-Linked Integration KW - chemisch-induzierte Dislokation KW - Austausch zwischen zwei Spezies Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-628569 ER - TY - GEN A1 - Ehrlich, Elias A1 - Kath, Nadja Jeanette A1 - Gaedke, Ursula T1 - The shape of a defense-growth trade-off governs seasonal trait dynamics in natural phytoplankton T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Theory predicts that trade-offs, quantifying costs of functional trait adjustments, crucially affect community trait adaptation to altered environmental conditions, but empirical verification is scarce. We evaluated trait dynamics (antipredator defense, maximum growth rate, and phosphate affinity) of a lake phytoplankton community in a seasonally changing environment, using literature trait data and 21 years of species-resolved high-frequency biomass measurements. The trait data indicated a concave defense-growth trade-off, promoting fast-growing species with intermediate defense. With seasonally increasing grazing pressure, the community shifted toward higher defense levels at the cost of lower growth rates along the trade-off curve, while phosphate affinity explained some deviations from it. We discuss how low fitness differences of species, inferred from model simulations, in concert with stabilizing mechanisms, e.g., arising from further trait dimensions, may lead to the observed phytoplankton diversity. In conclusion, quantifying trade-offs is key for predictions of community trait adaptation and biodiversity under environmental change. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1390 KW - functional traits KW - community ecology KW - evolution KW - lake KW - mechanisms KW - diversity KW - plankton KW - fitness KW - maintenance KW - coexistence Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-513956 SN - 1866-8372 IS - 6 ER - TY - GEN A1 - Masigol, Hossein A1 - Khodaparast, Seyed Akbar A1 - Mostowfizadeh-Ghalamfarsa, Reza A1 - Rojas-Jimenez, Keilor A1 - Woodhouse, Jason Nicholas A1 - Neubauer, Darshan A1 - Grossart, Hans-Peter T1 - Taxonomical and functional diversity of Saprolegniales in Anzali lagoon, Iran T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Studies on the diversity, distribution and ecological role of Saprolegniales (Oomycota) in freshwater ecosystems are currently receiving attention due to a greater understanding of their role in carbon cycling in various aquatic ecosystems. In this study, we characterized several Saprolegniales species isolated from Anzali lagoon, Gilan province, Iran, using morphological and molecular methods. Four species of Saprolegnia were identified, including S. anisospora and S. diclina as first reports for Iran, as well as Achlya strains, which were closely related to A. bisexualis, A. debaryana and A. intricata. Evaluation of the ligno-, cellulo- and chitinolytic activities was performed using plate assay methods. Most of the Saprolegniales isolates were obtained in autumn, and nearly 50% of the strains showed chitinolytic and cellulolytic activities. However, only a few Saprolegniales strains showed lignolytic activities. This study has important implications for better understanding the ecological niche of oomycetes, and to differentiate them from morphologically similar, but functionally different aquatic fungi in freshwater ecosystems. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1395 KW - Achlya KW - Saprolegnia KW - aquatic ecosystems KW - carbon cycling KW - polymer degradation KW - Saprolegniaceae KW - Achlyaceae Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515820 SN - 1866-8372 IS - 1 ER - TY - GEN A1 - Crawford, Tim A1 - Karamat, Fazeelat A1 - Lehotai, Nóra A1 - Rentoft, Matilda A1 - Blomberg, Jeanette A1 - Strand, Åsa A1 - Björklund, Stefan T1 - Specific functions for mediator complex subunits from different modules in the transcriptional response of arabidopsis thaliana to abiotic stress T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Adverse environmental conditions are detrimental to plant growth and development. Acclimation to abiotic stress conditions involves activation of signaling pathways which often results in changes in gene expression via networks of transcription factors (TFs). Mediator is a highly conserved co-regulator complex and an essential component of the transcriptional machinery in eukaryotes. Some Mediator subunits have been implicated in stress-responsive signaling pathways; however, much remains unknown regarding the role of plant Mediator in abiotic stress responses. Here, we use RNA-seq to analyze the transcriptional response of Arabidopsis thaliana to heat, cold and salt stress conditions. We identify a set of common abiotic stress regulons and describe the sequential and combinatorial nature of TFs involved in their transcriptional regulation. Furthermore, we identify stress-specific roles for the Mediator subunits MED9, MED16, MED18 and CDK8, and putative TFs connecting them to different stress signaling pathways. Our data also indicate different modes of action for subunits or modules of Mediator at the same gene loci, including a co-repressor function for MED16 prior to stress. These results illuminate a poorly understood but important player in the transcriptional response of plants to abiotic stress and identify target genes and mechanisms as a prelude to further biochemical characterization. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1399 KW - regulate gene expression KW - signal transduction KW - circadian clock KW - plant Mediator KW - salicylic-acid KW - activation KW - jasmonate KW - network KW - defense KW - MED16 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-513666 SN - 1866-8372 IS - 1 ER - TY - GEN A1 - Moradian, Hanieh A1 - Roch, Toralf A1 - Lendlein, Andreas A1 - Gossen, Manfred T1 - mRNA transfection-induced activation of primary human monocytes and macrophages BT - Dependence on carrier system and nucleotide modifcation T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Monocytes and macrophages are key players in maintaining immune homeostasis. Identifying strategies to manipulate their functions via gene delivery is thus of great interest for immunological research and biomedical applications. We set out to establish conditions for mRNA transfection in hard-to-transfect primary human monocytes and monocyte-derived macrophages due to the great potential of gene expression from in vitro transcribed mRNA for modulating cell phenotypes. mRNA doses, nucleotide modifications, and different carriers were systematically explored in order to optimize high mRNA transfer rates while minimizing cell stress and immune activation. We selected three commercially available mRNA transfection reagents including liposome and polymer-based formulations, covering different application spectra. Our results demonstrate that liposomal reagents can particularly combine high gene transfer rates with only moderate immune cell activation. For the latter, use of specific nucleotide modifications proved essential. In addition to improving efficacy of gene transfer, our findings address discrete aspects of innate immune activation using cytokine and surface marker expression, as well as cell viability as key readouts to judge overall transfection efficiency. The impact of this study goes beyond optimizing transfection conditions for immune cells, by providing a framework for assessing new gene carrier systems for monocyte and macrophage, tailored to specific applications. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1403 KW - sirna transfection KW - mediated delivery KW - gene delivery KW - efficient KW - immunogenicity KW - lipoplexes KW - cells KW - therapeutics KW - polarization KW - pathways Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515694 SN - 1866-8372 IS - 1 ER - TY - GEN A1 - Bäurle, Isabel A1 - Trindade, Inês T1 - Chromatin regulation of somatic abiotic stress memory T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - In nature, plants are often subjected to periods of recurrent environmental stress that can strongly affect their development and productivity. To cope with these conditions, plants can remember a previous stress, which allows them to respond more efficiently to a subsequent stress, a phenomenon known as priming. This ability can be maintained at the somatic level for a few days or weeks after the stress is perceived, suggesting that plants can store information of a past stress during this recovery phase. While the immediate responses to a single stress event have been extensively studied, knowledge on priming effects and how stress memory is stored is still scarce. At the molecular level, memory of a past condition often involves changes in chromatin structure and organization, which may be maintained independently from transcription. In this review, we will summarize the most recent developments in the field and discuss how different levels of chromatin regulation contribute to priming and plant abiotic stress memory. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1408 KW - abiotic stress KW - chromatin regulation KW - heat stress memory KW - histone modifications, priming KW - transcriptional memory KW - vernalization Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-516668 SN - 1866-8372 IS - 17 ER - TY - GEN A1 - Obbard, Darren J. A1 - Shi, Mang A1 - Roberts, Katherine E. A1 - Longdon, Ben A1 - Dennis, Alice B. T1 - A new lineage of segmented RNA viruses infecting animals T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Metagenomic sequencing has revolutionised our knowledge of virus diversity, with new virus sequences being reported faster than ever before. However, virus discovery from metagenomic sequencing usually depends on detectable homology: without a sufficiently close relative, so-called ‘dark’ virus sequences remain unrecognisable. An alternative approach is to use virus-identification methods that do not depend on detecting homology, such as virus recognition by host antiviral immunity. For example, virus-derived small RNAs have previously been used to propose ‘dark’ virus sequences associated with the Drosophilidae (Diptera). Here, we combine published Drosophila data with a comprehensive search of transcriptomic sequences and selected meta-transcriptomic datasets to identify a completely new lineage of segmented positive-sense single-stranded RNA viruses that we provisionally refer to as the Quenyaviruses. Each of the five segments contains a single open reading frame, with most encoding proteins showing no detectable similarity to characterised viruses, and one sharing a small number of residues with the RNA-dependent RNA polymerases of single- and double-stranded RNA viruses. Using these sequences, we identify close relatives in approximately 20 arthropods, including insects, crustaceans, spiders, and a myriapod. Using a more conserved sequence from the putative polymerase, we further identify relatives in meta-transcriptomic datasets from gut, gill, and lung tissues of vertebrates, reflecting infections of vertebrates or of their associated parasites. Our data illustrate the utility of small RNAs to detect viruses with limited sequence conservation, and provide robust evidence for a new deeply divergent and phylogenetically distinct RNA virus lineage. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1411 KW - metagenome KW - RNA virus KW - dark virus KW - arthropod KW - RNA interference Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-516040 SN - 1866-8372 IS - 1 ER -