@misc{LiaimerJensenDittmannThuenemann2016,
  author    = {Liaimer, Anton and Jensen, John B. and Dittmann-Th{\"u}nemann, Elke},
  title     = {A genetic and chemical perspective on symbiotic recruitment of cyanobacteria of the genus Nostoc into the host plant Blasia pusilla L.},
  series = {Frontiers in microbiology},
  journal   = {Frontiers in microbiology},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407179},
  pages     = {16},
  year      = {2016},
  abstract  = {Liverwort Blasia pusilla L. recruits soil nitrogen-fixing cyanobacteria of genus Nostoc as symbiotic partners. In this work we compared Nostoc community composition inside the plants and in the soil around them from two distant locations in Northern Norway. STRR fingerprinting and 16S rDNA phylogeny reconstruction showed a remarkable local diversity among isolates assigned to several Nostoc clades. An extensive web of negative allelopathic interactions was recorded at an agricultural site, but not at the undisturbed natural site. The cell extracts of the cyanobacteria did not show antimicrobial activities, but four isolates were shown to be cytotoxic to human cells. The secondary metabolite profiles of the isolates were mapped by MALDI-TOF MS, and the most prominent ions were further analyzed by Q-TOF for MS/MS aided identification. Symbiotic isolates produced a great variety of small peptide-like substances, most of which lack any record in the databases. Among identified compounds we found microcystin and nodularin variants toxic to eukaryotic cells. Microcystin producing chemotypes were dominating as symbiotic recruits but not in the free-living community. In addition, we were able to identify several novel aeruginosins and banyaside-like compounds, as well as nostocyclopeptides and nosperin.},
  language  = {en}
}
@misc{KrupinskiBozorgLarssonetal.2016,
  author    = {Krupinski, Pawel and Bozorg, Behruz and Larsson, Andr{\´e} and Pietra, Stefano and Grebe, Markus and J{\"o}nsson, Henrik},
  title     = {A model analysis of mechanisms for radial microtubular patterns at root hair initiation sites},
  series = {Frontiers in plant science},
  journal   = {Frontiers in plant science},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407181},
  pages     = {12},
  year      = {2016},
  abstract  = {Plant cells have two main modes of growth generating anisotropic structures. Diffuse growth where whole cell walls extend in specific directions, guided by anisotropically positioned cellulose fibers, and tip growth, with inhomogeneous addition of new cell wall material at the tip of the structure. Cells are known to regulate these processes via molecular signals and the cytoskeleton. Mechanical stress has been proposed to provide an input to the positioning of the cellulose fibers via cortical microtubules in diffuse growth. In particular, a stress feedback model predicts a circumferential pattern of fibers surrounding apical tissues and growing primordia, guided by the anisotropic curvature in such tissues. In contrast, during the initiation of tip growing root hairs, a star-like radial pattern has recently been observed. Here, we use detailed finite element models to analyze how a change in mechanical properties at the root hair initiation site can lead to star-like stress patterns in order to understand whether a stress-based feedback model can also explain the microtubule patterns seen during root hair initiation. We show that two independent mechanisms, individually or combined, can be sufficient to generate radial patterns. In the first, new material is added locally at the position of the root hair. In the second, increased tension in the initiation area provides a mechanism. Finally, we describe how a molecular model of Rho-of-plant (ROP) GTPases activation driven by auxin can position a patch of activated ROP protein basally along a 2D root epidermal cell plasma membrane, paving the way for models where mechanical and molecular mechanisms cooperate in the initial placement and outgrowth of root hairs.},
  language  = {en}
}
@phdthesis{Shikangalah2016,
  author    = {Shikangalah, Rosemary Ndawapeka},
  title     = {An ecohydrological impact assessment in urban areas},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-102356},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ii, 105},
  year      = {2016},
  abstract  = {Over the last decades, the world's population has been growing at a faster rate, resulting in increased urbanisation, especially in developing countries. More than half of the global population currently lives in urbanised areas with an increasing tendency. The growth of cities results in a significant loss of vegetation cover, soil compaction and sealing of the soil surface which in turn results in high surface runoff during high-intensity storms and causes the problem of accelerated soil water erosion on streets and building grounds. Accelerated soil water erosion is a serious environmental problem in cities as it gives rise to the contamination of aquatic bodies, reduction of ground water recharge and increase in land degradation, and also results in damages to urban infrastructures, including drainage systems, houses and roads. Understanding the problem of water erosion in urban settings is essential for the sustainable planning and management of cities prone to water erosion. However, in spite of the vast existence of scientific literature on water erosion in rural regions, a concrete understanding of the underlying dynamics of urban erosion still remains inadequate for the urban dryland environments. This study aimed at assessing water erosion and the associated socio-environmental determinants in a typical dryland urban area and used the city of Windhoek, Namibia, as a case study. The study used a multidisciplinary approach to assess the problem of water erosion. This included an in depth literature review on current research approaches and challenges of urban erosion, a field survey method for the quantification of the spatial extent of urban erosion in the dryland city of Windhoek, and face to face interviews by using semi-structured questionnaires to analyse the perceptions of stakeholders on urban erosion. The review revealed that around 64\% of the literatures reviewed were conducted in the developed world, and very few researches were carried out in regions with extreme climate, including dryland regions. Furthermore, the applied methods for erosion quantification and monitoring are not inclusive of urban typical features and they are not specific for urban areas. The reviewed literature also lacked aspects aimed at addressing the issues of climate change and policies regarding erosion in cities. In a field study, the spatial extent and severity of an urban dryland city, Windhoek, was quantified and the results show that nearly 56\% of the city is affected by water erosion showing signs of accelerated erosion in the form of rills and gullies, which occurred mainly in the underdeveloped, informal and semi-formal areas of the city. Factors influencing the extent of erosion in Windhoek included vegetation cover and type, socio-urban factors and to a lesser extent slope estimates. A comparison of an interpolated field survey erosion map with a conventional erosion assessment tool (the Universal Soil Loss Equation) depicted a large deviation in spatial patterns, which underlines the inappropriateness of traditional non-urban erosion tools to urban settings and emphasises the need to develop new erosion assessment and management methods for urban environments. It was concluded that measures for controlling water erosion in the city need to be site-specific as the extent of erosion varied largely across the city. The study also analysed the perceptions and understanding of stakeholders of urban water erosion in Windhoek, by interviewing 41 stakeholders using semi-structured questionnaires. The analysis addressed their understanding of water erosion dynamics, their perceptions with regards to the causes and the seriousness of erosion damages, and their attitudes towards the responsibilities for urban erosion. The results indicated that there is less awareness of the process as a phenomenon, instead there is more awareness of erosion damages and the factors contributing to the damages. About 69\% of the stakeholders considered erosion damages to be ranging from moderate to very serious. However, there were notable disparities between the private householders and public authority groups. The study further found that the stakeholders have no clear understanding of their responsibilities towards the management of the control measures and payment for the damages. The private householders and local authority sectors pointed fingers at each other for the responsibilities for erosion damage payments and for putting up prevention measures. The reluctance to take responsibility could create a predicament for areas affected, specifically in the informal settlements where land management is not carried out by the local authority and land is not owned by the occupants. The study concluded that in order to combat urban erosion, it is crucial to understand diverse dynamics aggravating the process of urbanisation from different scales. Accordingly, the study suggests that there is an urgent need for the development of urban-specific approaches that aim at: (a) incorporating the diverse socio-economic-environmental aspects influencing erosion, (b) scientifically improving natural cycles that influence water storages and nutrients for plants in urbanised dryland areas in order to increase the amount of vegetation cover, (c) making use of high resolution satellite images to improve the adopted methods for assessing urban erosion, (d) developing water erosion policies, and (e) continuously monitoring the impact of erosion and the influencing processes from local, national and international levels.},
  language  = {en}
}
@misc{RoggenbuckBorghiSommaetal.2016,
  author    = {Roggenbuck, Dirk and Borghi, Maria Orietta and Somma, Valentina and B{\"u}ttner, Thomas and Schierack, Peter and Hanack, Katja and Grossi, Claudia and Bodio, Caterina and Macor, Paolo and von Landenberg, Philipp and Boccellato, Francesco and Mahler, Michael and Meroni, Pier Luigi},
  title     = {Antiphospholipid antibodies detected by line immunoassay differentiate among patients with antiphospholipid syndrome, with infections and asymptomatic carriers},
  series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  number    = {436},
  issn      = {1866-8372},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407211},
  pages     = {14},
  year      = {2016},
  abstract  = {Background Antiphospholipid antibodies (aPL) can be detected in asymptomatic carriers and infectious patients. The aim was to investigate whether a novel line immunoassay (LIA) differentiates between antiphospholipid syndrome (APS) and asymptomatic aPL+ carriers or patients with infectious diseases (infectious diseases controls (IDC)). Methods Sixty-one patients with APS (56 primary, 22/56 with obstetric events only, and 5 secondary), 146 controls including 24 aPL+ asymptomatic carriers and 73 IDC were tested on a novel hydrophobic solid phase coated with cardiolipin (CL), phosphatic acid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, beta2-glycoprotein I (β2GPI), prothrombin, and annexin V. Samples were also tested by anti-CL and anti-β2GPI ELISAs and for lupus anticoagulant activity. Human monoclonal antibodies (humoAbs) against human β2GPI or PL alone were tested on the same LIA substrates in the absence or presence of human serum, purified human β2GPI or after CL-micelle absorption. Results Comparison of LIA with the aPL-classification assays revealed good agreement for IgG/IgM aß2GPI and aCL. Anti-CL and anti-ß2GPI IgG/IgM reactivity assessed by LIA was significantly higher in patients with APS versus healthy controls and IDCs, as detected by ELISA. IgG binding to CL and ß2GPI in the LIA was significantly lower in aPL+ carriers and Venereal Disease Research Laboratory test (VDRL) + samples than in patients with APS. HumoAb against domain 1 recognized β2GPI bound to the LIA-matrix and in anionic phospholipid (PL) complexes. Absorption with CL micelles abolished the reactivity of a PL-specific humoAb but did not affect the binding of anti-β2GPI humoAbs. Conclusions The LIA and ELISA have good agreement in detecting aPL in APS, but the LIA differentiates patients with APS from infectious patients and asymptomatic carriers, likely through the exposure of domain 1.},
  language  = {en}
}
@misc{WessigBaderKlieretal.2016,
  author    = {Wessig, Pablo and Bader, Denise and Klier, Dennis Tobias and Hettrich, Cornelia and Bier, Frank Fabian},
  title     = {Detecting carbohydrate-lectin interactions using a fluorescent probe based on DBD dyes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-394382},
  pages     = {1235 -- 1238},
  year      = {2016},
  abstract  = {Herein we present an efficient synthesis of a biomimetic probe with modular construction that can be specifically bound by the mannose binding FimH protein - a surface adhesion protein of E. coli bacteria. The synthesis combines the new and interesting DBD dye with the carbohydrate ligand mannose via a Click reaction. We demonstrate the binding to E. coli bacteria over a large concentration range and also present some special characteristics of those molecules that are of particular interest for the application as a biosensor. In particular, the mix-and-measure ability and the very good photo-stability should be highlighted here.},
  language  = {en}
}
@misc{YanChenKaufmann2016,
  author    = {Yan, Wenhao and Chen, Dijun and Kaufmann, Kerstin},
  title     = {Efficient multiplex mutagenesis by RNA‑guided Cas9 and its use in the characterization of regulatory elements in the AGAMOUS gene},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90895},
  year      = {2016},
  abstract  = {Background: The efficiency of multiplex editing in plants by the RNA-guided Cas9 system is limited by efficient introduction of its components into the genome and by their activity. The possibility of introducing large fragment deletions by RNA-guided Cas9 tool provides the potential to study the function of any DNA region of interest in its 'endogenous' environment. Results: Here, an RNA-guided Cas9 system was optimized to enable efficient multiplex editing in Arabidopsis thaliana. We demonstrate the flexibility of our system for knockout of multiple genes, and to generate heritable largefragment deletions in the genome. As a proof of concept, the function of part of the second intron of the flower development gene AGAMOUS in Arabidopsis was studied by generating a Cas9-free mutant plant line in which part of this intron was removed from the genome. Further analysis revealed that deletion of this intron fragment results 40 \% decrease of AGAMOUS gene expression without changing the splicing of the gene which indicates that this regulatory region functions as an activator of AGAMOUS gene expression. Conclusions: Our modified RNA-guided Cas9 system offers a versatile tool for the functional dissection of coding and non-coding DNA sequences in plants.},
  language  = {en}
}
@phdthesis{Laux2016,
  author    = {Laux, Eva-Maria},
  title     = {Electric field-assisted immobilization and alignment of biomolecules},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90271},
  school      = {Universit{\"a}t Potsdam},
  pages     = {IX, 120},
  year      = {2016},
  abstract  = {In this dissertation, an electric field-assisted method was developed and applied to achieve immobilization and alignment of biomolecules on metal electrodes in a simple one-step experiment. Neither modifications of the biomolecule nor of the electrodes were needed. The two major electrokinetic effects that lead to molecule motion in the chosen electrode configurations used were identified as dielectrophoresis and AC electroosmotic flow. To minimize AC electroosmotic flow, a new 3D electrode configuration was designed. Thus, the influence of experimental parameters on the dielectrophoretic force and the associated molecule movement could be studied. Permanent immobilization of proteins was examined and quantified absolutely using an atomic force microscope. By measuring the volumes of the immobilized protein deposits, a maximal number of proteins contained therein was calculated. This was possible since the proteins adhered to the tungsten electrodes even after switching off the electric field. The permanent immobilization of functional proteins on surfaces or electrodes is one crucial prerequisite for the fabrication of biosensors. Furthermore, the biofunctionality of the proteins must be retained after immobilization. Due to the chemical or physical modifications on the proteins caused by immobilization, their biofunctionality is sometimes hampered. The activity of dielectrophoretically immobilized proteins, however, was proven here for an enzyme for the first time. The enzyme horseradish peroxidase was used exemplarily, and its activity was demonstrated with the oxidation of dihydrorhodamine 123, a non-fluorescent precursor of the fluorescence dye rhodamine 123. Molecular alignment and immobilization - reversible and permanent - was achieved under the influence of inhomogeneous AC electric fields. For orientational investigations, a fluorescence microscope setup, a reliable experimental procedure and an evaluation protocol were developed and validated using self-made control samples of aligned acridine orange molecules in a liquid crystal. Lambda-DNA strands were stretched and aligned temporarily between adjacent interdigitated electrodes, and the orientation of PicoGreen molecules, which intercalate into the DNA strands, was determined. Similarly, the aligned immobilization of enhanced Green Fluorescent Protein was demonstrated exploiting the protein's fluorescence and structural properties. For this protein, the angle of the chromophore with respect to the protein's geometrical axis was determined in good agreement with X-ray crystallographic data. Permanent immobilization with simultaneous alignment of the proteins was achieved along the edges, tips and on the surface of interdigitated electrodes. This was the first demonstration of aligned immobilization of proteins by electric fields. Thus, the presented electric field-assisted immobilization method is promising with regard to enhanced antibody binding capacities and enzymatic activities, which is a requirement for industrial biosensor production, as well as for general interaction studies of proteins.},
  language  = {en}
}
@misc{EldridgeŁangowskiStaceyetal.2016,
  author    = {Eldridge, Tilly and Łangowski, Łukasz and Stacey, Nicola and Jantzen, Friederike and Moubayidin, Laila and Sicard, Adrien and Southam, Paul and Kennaway, Richard and Lenhard, Michael and Coen, Enrico S. and {\O}stergaard, Lars},
  title     = {Fruit shape diversity in the Brassicaceae is generated by varying patterns of anisotropy},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {986},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-43804},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-438041},
  pages     = {3394 -- 3406},
  year      = {2016},
  abstract  = {Fruits exhibit a vast array of different 3D shapes, from simple spheres and cylinders to more complex curved forms; however, the mechanism by which growth is oriented and coordinated to generate this diversity of forms is unclear. Here, we compare the growth patterns and orientations for two very different fruit shapes in the Brassicaceae: the heart-shaped Capsella rubella silicle and the near-cylindrical Arabidopsis thaliana silique. We show, through a combination of clonal and morphological analyses, that the different shapes involve different patterns of anisotropic growth during three phases. These experimental data can be accounted for by a tissue level model in which specified growth rates vary in space and time and are oriented by a proximodistal polarity field. The resulting tissue conflicts lead to deformation of the tissue as it grows. The model allows us to identify tissue-specific and temporally specific activities required to obtain the individual shapes. One such activity may be provided by the valve-identity gene FRUITFULL, which we show through comparative mutant analysis to modulate fruit shape during post-fertilisation growth of both species. Simple modulations of the model presented here can also broadly account for the variety of shapes in other Brassicaceae species, thus providing a simplified framework for fruit development and shape diversity.},
  language  = {en}
}
@phdthesis{Connor2016,
  author    = {Connor, Daniel Oliver},
  title     = {Identifikation und Charakterisierung neuer immunogener Proteine und anschließende Generierung rekombinanter Antik{\"o}rper mittels Phage Display},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-104120},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VII, 112, lv Seiten},
  year      = {2016},
  abstract  = {Seit der Einf{\"u}hrung von Antibiotika in die medizinische Behandlung von bakteriellen Infektionskrankheiten existiert ein Wettlauf zwischen der Evolution von Bakterienresistenzen und der Entwicklung wirksamer Antibiotika. W{\"a}hrend bis in die 80er Jahre verst{\"a}rkt an neuen Antibiotika geforscht wurde, gewinnen multiresistente Keime heute zunehmend die Oberhand. Um einzelne Pathogene erfolgreich nachzuweisen und zu bek{\"a}mpfen, ist ein grundlegendes Wissen {\"u}ber den Erreger unumg{\"a}nglich. Bakterielle Proteine, die bei einer Infektion vorrangig vom Immunsystem prozessiert und pr{\"a}sentiert werden, k{\"o}nnten f{\"u}r die Entwicklung von Impfstoffen oder gezielten Therapeutika n{\"u}tzlich sein. Auch f{\"u}r die Diagnostik w{\"a}ren diese immundominanten Proteine interessant. Allerdings herrscht ein Mangel an Wissen {\"u}ber spezifische Antigene vieler pathogener Bakterien, die eine eindeutige Diagnostik eines einzelnen Erregers erlauben w{\"u}rden. Daher wurden in dieser Arbeit vier verschiedene Humanpathogene mittels Phage Display untersucht: Neisseria gonorrhoeae, Neisseria meningitidis, Borrelia burgdorferi und Clostridium difficile. Hierf{\"u}r wurden aus der genomischen DNA der vier Erreger Bibliotheken konstruiert und durch wiederholte Selektion und Amplifikation, dem sogenannten Panning, immunogene Proteine isoliert. F{\"u}r alle Erreger bis auf C. difficile wurden immunogene Proteine aus den jeweiligen Bibliotheken isoliert. Die identifizierten Proteine von N. meningitidis und B. burgdorferi waren gr{\"o}ßtenteils bekannt, konnten aber in dieser Arbeit durch Phage Display verifiziert werden. F{\"u}r N. gonorrhoeae wurden 21 potentiell immunogene Oligopeptide isoliert, von denen sechs Proteine als neue zuvor unbeschriebene Proteine mit immunogenem Charakter identifiziert wurden. Von den Phagen-pr{\"a}sentierten Oligopeptide der 21 immunogenen Proteine wurden Epitopmappings mit verschiedenen polyklonalen Antik{\"o}rpern durchgef{\"u}hrt, um immunogene Bereiche n{\"a}her zu identifizieren und zu charakterisieren. Bei zehn Proteinen wurden lineare Epitope eindeutig mit drei polyklonalen Antik{\"o}rpern identifiziert, von f{\"u}nf weiteren Proteinen waren Epitope mit mindestens einem Antik{\"o}rper detektierbar. F{\"u}r eine weitere Charakterisierung der ermittelten Epitope wurden Alaninscans durchgef{\"u}hrt, die eine detaillierte Auskunft {\"u}ber kritische Aminos{\"a}uren f{\"u}r die Bindung des Antik{\"o}rpers an das Epitop geben. Ausgehend von dem neu identifizierten Protein mit immunogenem Charakter NGO1634 wurden 26 weitere Proteine aufgrund ihrer funktionellen {\"A}hnlichkeit ausgew{\"a}hlt und mithilfe bioinformatischer Analysen auf ihre Eignung zur Entwicklung einer diagnostischen Anwendung analysiert. Durch Ausschluss der meisten Proteine aufgrund ihrer Lokalisation, Membrantopologie oder unspezifischen Proteinsequenz wurden scFv-Antik{\"o}rper gegen acht Proteine mittels Phage Display generiert und anschließend als scFv-Fc-Fusionsantik{\"o}rper produziert und charakterisiert. Die hier identifizierten Proteine und linearen Epitope k{\"o}nnten einen Ansatzpunkt f{\"u}r die Entwicklung einer diagnostischen oder therapeutischen Anwendung bieten. Lineare Epitopsequenzen werden h{\"a}ufig f{\"u}r die Impfstoffentwicklung eingesetzt, sodass vor allem die in dieser Arbeit bestimmten Epitope von Membranproteinen interessante Kandidaten f{\"u}r weitere Untersuchungen in diese Richtung sind. Durch weitere Untersuchungen k{\"o}nnten m{\"o}glicherweise unbekannte Virulenzfaktoren entdeckt werden, deren Inhibierung einen entscheidenden Einfluss auf Infektionen haben k{\"o}nnten.},
  language  = {de}
}
@phdthesis{Nietzsche2016,
  author    = {Nietzsche, Madlen},
  title     = {Identifizierung und Charakterisierung neuer Komponenten der SnRK1-Signaltransduktion in Arabidopsis thaliana},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-98678},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xi, 182},
  year      = {2016},
  abstract  = {F{\"u}r alle Organismen ist die Aufrechterhaltung ihres energetischen Gleichgewichts unter fluktuierenden Umweltbedingungen lebensnotwendig. In Eukaryoten steuern evolution{\"a}r konservierte Proteinkinasen, die in Pflanzen als SNF1-RELATED PROTEIN KINASE1 (SnRK1) bezeichnet werden, die Adaption an Stresssignale aus der Umwelt und an die Limitierung von N{\"a}hrstoffen und zellul{\"a}rer Energie. Die Aktivierung von SnRK1 bedingt eine umfangreiche transkriptionelle Umprogrammierung, die allgemein zu einer Repression energiekonsumierender Prozesse wie beispielsweise Zellteilung und Proteinbiosynthese und zu einer Induktion energieerzeugender, katabolischer Stoffwechselwege f{\"u}hrt. Wie unterschiedliche Signale zu einer generellen sowie teilweise gewebe- und stressspezifischen SnRK1-vermittelten Antwort f{\"u}hren ist bisher noch nicht ausreichend gekl{\"a}rt, auch weil bislang nur wenige Komponenten der SnRK1-Signaltransduktion identifiziert wurden. In dieser Arbeit konnte ein Protein-Protein-Interaktionsnetzwerk um die SnRK1αUntereinheiten aus Arabidopsis AKIN10/AKIN11 etabliert werden. Dadurch wurden zun{\"a}chst Mitglieder der pflanzenspezifischen DUF581-Proteinfamilie als Interaktionspartner der SnRK1α-Untereinheiten identifiziert. Diese Proteine sind {\"u}ber ihre konservierte DUF581Dom{\"a}ne, in der ein Zinkfinger-Motiv lokalisiert ist, f{\"a}hig mit AKIN10/AKIN11 zu interagieren. In planta Ko-Expressionsanalysen zeigten, dass die DUF581-Proteine eine Verschiebung der nucleo-cytoplasmatischen Lokalisierung von AKIN10 hin zu einer nahezu ausschließlichen zellkernspezifischen Lokalisierung beg{\"u}nstigen sowie die Ko-Lokalisierung von AKIN10 und DUF581-Proteinen im Nucleus. In Bimolekularen Fluoreszenzkomplementations-Analysen konnte die zellkernspezifische Interaktion von DUF581-Proteinen mit SnRK1α-Untereinheiten in planta best{\"a}tigt werden. Außerhalb der DUF581-Dom{\"a}ne weisen die Proteine einander keine große Sequenz{\"a}hnlichkeit auf. Aufgrund ihrer F{\"a}higkeit mit SnRK1 zu interagieren, dem Fehlen von SnRK1Phosphorylierungsmotiven sowie ihrer untereinander sehr variabler gewebs-, entwicklungs- und stimulusspezifischer Expression wurde f{\"u}r DUF581-Proteine eine Funktion als Adaptoren postuliert, die unter bestimmten physiologischen Bedingungen spezifische Substratproteine in den SnRK1-Komplex rekrutieren. Auf diese Weise k{\"o}nnten DUF581Proteine die Interaktion von SnRK1 mit deren Zielproteinen modifizieren und eine Feinjustierung der SnRK1-Signalweiterleitung erm{\"o}glichen. Durch weiterf{\"u}hrende Interaktionsstudien konnten DUF581-interagierende Proteine darunter Transkriptionsfaktoren, Proteinkinasen sowie regulatorische Proteine gefunden werden, die teilweise ebenfalls Wechselwirkungen mit SnRK1α-Untereinheiten aufzeigten. Im Rahmen dieser Arbeit wurde eines dieser Proteine f{\"u}r das eine Beteiligung an der SnRK1Signalweiterleitung als Transkriptionsregulator vermutet wurde n{\"a}her charakterisiert. STKR1 (STOREKEEPER RELATED 1), ein spezifischer Interaktionspartner von DUF581-18, geh{\"o}rt zu einer pflanzenspezifischen Leucin-Zipper-Transkriptionsfaktorfamilie und interagiert in Hefe sowie in planta mit SnRK1. Die zellkernspezifische Interaktion von STKR1 und AKIN10 in Pflanzen unterst{\"u}tzt die Vermutung der kooperativen Regulation von Zielgenen. Weiterhin stabilisierte die Anwesenheit von AKIN10 die Proteingehalte von STKR1, das wahrscheinlich {\"u}ber das 26S Proteasom abgebaut wird. Da es sich bei STKR1 um ein Phosphoprotein mit SnRK1-Phosphorylierungsmotiv handelt, stellt es sehr wahrscheinlich ein SnRK1-Substrat dar. Allerdings konnte eine SnRK1-vermittelte Phosphorylierung von STKR1 in dieser Arbeit nicht gezeigt werden. Der Verlust von einer Phosphorylierungsstelle beeinflusste die Homo- und Heterodimerisierungsf{\"a}higkeit von STKR1 in Hefeinteraktionsstudien, wodurch eine erh{\"o}hte Spezifit{\"a}t der Zielgenregulation erm{\"o}glicht werden k{\"o}nnte. Außerdem wurden Arabidopsis-Pflanzen mit einer ver{\"a}nderten STKR1-Expression ph{\"a}notypisch, physiologisch und molekularbiologisch charakterisiert. W{\"a}hrend der Verlust der STKR1-Expression zu Pflanzen f{\"u}hrte, die sich kaum von Wildtyp-Pflanzen unterschieden, bedingte die konstitutive {\"U}berexpression von STKR1 ein stark vermindertes Pflanzenwachstum sowie Entwicklungsverz{\"o}gerungen hinsichtlich der Bl{\"u}hinduktion und Seneszenz {\"a}hnlich wie sie auch bei SnRK1α-{\"U}berexpression beschrieben wurden. Pflanzen dieser Linien waren nicht in der Lage Anthocyane zu akkumulieren und enthielten geringere Gehalte an Chlorophyll und Carotinoiden. Neben einem erh{\"o}hten n{\"a}chtlichen St{\"a}rkeumsatz waren die Pflanzen durch geringere Saccharosegehalte im Vergleich zum Wildtyp gekennzeichnet. Eine Transkriptomanalyse ergab, dass in den STKR1-{\"u}berexprimierenden Pflanzen unter Energiemangelbedingungen, hervorgerufen durch eine verl{\"a}ngerte Dunkelphase, eine gr{\"o}ßere Anzahl an Genen im Vergleich zum Wildtyp differentiell reguliert war als w{\"a}hrend der Lichtphase. Dies spricht f{\"u}r eine Beteiligung von STKR1 an Prozessen, die w{\"a}hrend der verl{\"a}ngerten Dunkelphase aktiv sind. Ein solcher ist beispielsweise die SnRK1-Signaltransduktion, die unter energetischem Stress aktiviert wird. Die STKR1{\"U}berexpression f{\"u}hrte zudem zu einer verst{\"a}rkten transkriptionellen Induktion von Abwehrassoziierten Genen sowie NAC- und WRKY-Transkriptionsfaktoren nach verl{\"a}ngerter Dunkelphase. Die Transkriptomdaten deuteten auf eine stimulusunabh{\"a}ngige Induktion von Abwehrprozessen hin und konnten eine Erkl{\"a}rung f{\"u}r die ph{\"a}notypischen und physiologischen Auff{\"a}lligkeiten der STKR1-{\"U}berexprimierer liefern.},
  language  = {de}
}