TY - THES A1 - Kersting, Katerina T1 - Development of a CRISPR/Cas gene editing technique for the coccolithophore Chrysotila carterae Y1 - 2024 ER - TY - THES A1 - You, Lili T1 - Chloroplast engineering for recombinant protein production and stress protection Y1 - 2024 ER - TY - THES A1 - Székely, András Csaba T1 - Long-distance circadian coordination via a phloem-delivered mobile transcript Y1 - 2024 ER - TY - THES A1 - Montulet, Orianne T1 - Functional characterization of putative interactors of the Cellulose Synthase Complex T1 - Funktionelle Charakterisierung von mutmaßlichen Interaktoren des Cellulose-Synthase-Komplexes N2 - The plant cell wall plays several crucial roles during plant development with its integrity acting as key signalling component for growth regulation during biotic and abiotic stresses. Cellulose microfibrils, the principal load-bearing components is the major component of the primary cell wall, whose synthesis is mediated by microtubule-associated CELLULOSE SYNTHASE (CESA) COMPLEXES (CSC). Previous studies have shown that CSC interacting proteins COMPANION OF CELLULOSE SYNTHASE (CC) facilitate sustained cellulose synthesis during salt stress by promoting repolymerization of cortical microtubules. However, our understanding of cellulose synthesis during salt stress remains incomplete. In this study, a pull-down of CC1 protein led to the identification of a novel interactor, termed LEA-like. Phylogenetic analysis revealed that LEA-like belongs to the LATE EMBRYOGENESIS ABUNDANT (LEA) protein family, specifically to the LEA_2 subgroup, showing a close relationship with the CC proteins. Roots of the double mutants lea-like and its closest homolog emb3135 exhibited hypersensitivity when grown on cellulose synthesis inhibitors. Further analysis of higher-order mutants of lea-like, emb3135, and cesa6 demonstrated a genetic interaction between them indicating a significant role in cellulose synthesis. Live-cell imaging revealed that both LEA-like and EMB3135 migrated with the CSC at the plasma membrane along microtubule tracks in control and oryzalin-treated conditions which destabilize microtubules, suggesting a tight interaction. Investigation of fluorescently labeled lines of different domains of the LEA-like protein revealed that the N-terminal cytosolic domain of LEA-like colocalizes with microtubules, suggesting a physical association between the two. Considering the established role of LEA proteins in abiotic stress tolerance, we performed phenotypic analysis of the mutant under various stresses. Growth of double mutants of lea-like and emb3135 on NaCl containing media resulted in swelling of root cell indicating a putative role in salt stress tolerance. Supportive of this the quadruple mutant, lacking LEA-like, EMB3135, CC1, and CC2 proteins, exhibited a severe root growth defect on NaCl media compared to control conditions. Live-cell imaging revealed that under salt stress, the LEA-like protein forms aggregates in the plasma membrane. In conclusion, this study has unveiled two novel interactors of the CSC that act with the CC proteins that regulate plant growth in response to salt stress providing new insights into the intricate regulation of cellulose synthesis, particularly under such conditions. N2 - Die pflanzliche Zellwand spielt während der Pflanzenentwicklung mehrere entscheidende Rollen, wobei ihre Integrität als zentrale Signalkomponente für die Wachstumsregulierung bei biotischem und abiotischem Stress fungiert. Zellulose-Mikrofibrillen, die wichtigsten tragenden Komponenten, sind der Hauptbestandteil der primären Zellwand, deren Synthese durch Mikrotubuli assoziierte CELLULOSE SYNTHASE (CESA) Komplexe (CSC) vermittelt wird. Frühere Studien haben gezeigt, dass die mit den CSC interagierenden Proteinen COMPANION OF CELLULOSE SYNTHASE (CC) die anhaltende Zellulosesynthese bei Salzstress erleichtern, indem sie die Repolymerisation der kortikalen Mikrotubuli fördern. Unser Verständnis der Zellulosesynthese bei Salzstress ist jedoch noch unvollständig. In dieser Studie führte ein Pull-down des CC1-Proteins zur Identifizierung eines neuen Interaktors, der als LEA-like bezeichnet wird. Eine phylogenetische Analyse ergab, dass LEA-like zur Late Embryogenesis Abundant (LEA)-Proteinfamilie gehört, insbesondere zur LEA_2-Untergruppe, die eine enge Beziehung zu den CC-Proteinen aufweist. Die Wurzeln der Doppelmutanten lea-like und seines engsten Homologen emb3135 zeigten eine Überempfindlichkeit, wenn sie auf Zellulose-Synthese-Inhibitoren wuchsen. Weitere Analysen von Mutanten höherer Ordnung von lea-like, emb3135 und cesa6 zeigten eine genetische Interaktion zwischen ihnen, die auf eine bedeutende Rolle bei der Zellulosesynthese hinweist. Die Bildgebung in lebenden Zellen zeigte, dass sowohl LEA-like als auch EMB3135 mit dem CSC an der Plasmamembran entlang von Mikrotubuli-Spuren wandern, und zwar sowohl unter Kontrollbedingungen als auch unter Oryzalin-Behandlung, die die Mikrotubuli destabilisiert, was auf eine enge Interaktion hindeutet. Die Untersuchung von fluoreszenzmarkierten Linien verschiedener Domänen des LEA-like-Proteins ergab, dass die N-terminale zytosolische Domäne von LEA-like mit Mikrotubuli kolokalisiert, was auf eine physische Verbindung zwischen den beiden hindeutet. In Anbetracht der bekannten Rolle der LEA-Proteine bei der abiotischen Stresstoleranz haben wir eine phänotypische Analyse der Mutante unter verschiedenen Stressbedingungen durchgeführt. Das Wachstum von Doppelmutanten von lea-like und emb3135 auf NaCl-haltigen Medien führte zu einem Anschwellen der Wurzelzellen, was auf eine mutmaßliche Rolle bei der Salzstresstoleranz hindeutet. Die Vierfachmutante, der die Proteine LEA-like, EMB3135, CC1 und CC2 fehlen, wies im Vergleich zu den Kontrollbedingungen auf NaCl-Medien einen schweren Wachstumsdefekt der Wurzeln auf. Die Bildgebung in lebenden Zellen zeigte, dass das LEA-like-Protein unter Salzstress Aggregate in der Plasmamembran bildet. Zusammenfassend lässt sich sagen, dass diese Studie zwei neue Interaktoren des CSC aufgedeckt hat, die mit den CC-Proteinen zusammenwirken und das Pflanzenwachstum als Reaktion auf Salzstress regulieren. KW - cell wall KW - cellulose KW - salt stress KW - cellulose synthase complex KW - Arabidopsis KW - Zellwand KW - zellulose, Salzstress KW - Cellulose-Synthese-Complex KW - Arabidopsis Y1 - 2024 ER - TY - THES A1 - Apodiakou, Anastasia T1 - Analysis of the regulation of SDI genes, unravelling the role of the SLIM1 transcription factor, and the SNRK3.15 kinase in Arabidopsis under sulfur deprivation Y1 - 2024 ER - TY - THES A1 - Karakas, Esra T1 - High-resolution studies of epistasis in tomato metabolism T1 - Hochauflösende Studien zur Epistasierung des Tomatenstoffwechsels N2 - The inclusion of exotic germplasm serves as a crucial means to enhance allelic and consequently phenotypic diversity in inbred crop species. Such species have experienced a reduction in diversity due to artificial selection focused on a limited set of traits. The natural biodiversity within ecosystems presents an opportunity to explore various traits influencing plant survival, reproductive fitness and yield potential. In agricultural research, the study of wild species closely related to cultivated plants serves as a means to comprehend the genetic foundations of past domestication events and the polymorphisms essential for future breeding efforts to develop superior varieties. In order to examine the metabolic composition, pinpoint quantitative trait loci (QTL) and facilitate their resolution an extensive large-scale analysis of metabolic QTL (mQTL) was conducted on tomato backcross inbred lines (BILs) derived from a cross between the wild species S. pennellii (5240) incorporated into the background of S. lycopersicum cv. LEA determinate inbred which can be grown in open fields and cv. TOP indeterminate which can be grown in greenhouse conditions. A large number of mQTL associated with primary secondary and lipid metabolism in fruit were identified across the two BIL populations. Epistasis, the interactions between genes at different loci, has been an interest in molecular and quantitative genetics for many decades. The study of epistasis requires the analysis of very large populations with multiple independent genotypes that carry specific genomic regions. In order to understand the genetic basis of tomato fruit metabolism, I extended the work to investigate epistatic interactions of the genomic regions. In addition, two candidate genes were identified through quantitative trait loci underlying fruit-specific sucrose and jasmonic acid derivatives. Finally, in this study, I assessed the genetic framework of fruit metabolic traits with a high level of detail, utilizing the newly created Solanum pennellii (5240) backcrossed introgression lines (n=3000). This investigation resulted in the discovery of promising candidate loci associated with significant fruit quality traits, including those to the abundance of glutamic acid and aspartic acid crucial elements contributing to the development of acidity and flavors. N2 - Die Einbeziehung von exotischem Keimplasma ist ein wichtiges Mittel zur Verbesserung der allelischen und folglich auch der phänotypischen Vielfalt bei Inzuchtpflanzenarten. Bei diesen Arten hat die künstliche Selektion, die sich auf eine begrenzte Anzahl von Merkmalen konzentriert, zu einem Rückgang der Vielfalt geführt. Die natürliche Artenvielfalt in Ökosystemen bietet die Möglichkeit, verschiedene Merkmale zu erforschen, die das Überleben, die Reproduktionsfähigkeit und das Ertragspotenzial von Pflanzen beeinflussen. In der Agrarforschung dient die Untersuchung von Wildarten, die eng mit Kulturpflanzen verwandt sind, als Mittel zum Verständnis der genetischen Grundlagen vergangener Domestizierungsereignisse und der Polymorphismen, die für künftige Züchtungsbemühungen zur Entwicklung besserer Sorten wichtig sind. Um die metabolische Zusammensetzung zu untersuchen, quantitative Merkmalsloci (QTL) zu identifizieren und ihre Auflösung zu erleichtern, wurde eine umfangreiche Analyse metabolischer QTL (mQTL) an Tomaten-Rückkreuzungs-Inzuchtlinien (BILs) durchgeführt, die aus einer Kreuzung zwischen der Wildart S. pennellii (5240), die in den Hintergrund von S. lycopersicum cv. LEA determinate inbred, die im Freiland angebaut werden kann, und cv. TOP indeterminate, die unter Gewächshausbedingungen angebaut werden kann. In den beiden BIL-Populationen wurde eine große Anzahl von mQTL identifiziert, die mit dem primären Sekundär- und Lipidstoffwechsel in der Frucht in Verbindung stehen. Epistase, die Wechselwirkungen zwischen Genen an verschiedenen Loci, ist seit vielen Jahrzehnten ein Thema in der molekularen und quantitativen Genetik. Die Untersuchung der Epistase erfordert die Analyse sehr großer Populationen mit mehreren unabhängigen Genotypen, die bestimmte genomische Regionen tragen. Um die genetischen Grundlagen des Tomatenfruchtstoffwechsels zu verstehen, habe ich die Arbeit erweitert, um epistatische Interaktionen der genomischen Regionen zu untersuchen. Darüber hinaus wurden zwei Kandidatengene identifiziert, die über quantitative Merkmalsloci den fruchttypischen Saccharose- und Jasmonsäurederivaten zugrunde liegen. Schließlich habe ich in dieser Studie das genetische Gerüst der Fruchtstoffwechselmerkmale mit einem hohen Detaillierungsgrad bewertet, wobei ich die neu geschaffenen Solanum pennellii (5240) Rückkreuzungslinien (n=3000) verwendet habe. Diese Untersuchung führte zur Entdeckung vielversprechender Kandidatenloci, die mit bedeutenden Fruchtqualitätsmerkmalen assoziiert sind, einschließlich derjenigen, die mit der Fülle von Glutaminsäure und Asparaginsäure in Verbindung stehen - entscheidende Elemente, die zur Entwicklung von Säure und Aromen beitragen. KW - Epistasis KW - QTL mapping KW - metabolomics KW - backcross inbred line (BIL) KW - Epistase KW - QTL KW - Metabolomik KW - Rückkreuzungsinzuchtlinie (BIL) Y1 - 2024 ER - TY - JOUR A1 - Ogunkola, Moses Olalekan A1 - Guiraudie-Capraz, Gaelle A1 - Féron, François A1 - Leimkühler, Silke T1 - The Human Mercaptopyruvate Sulfurtransferase TUM1 Is Involved in Moco Biosynthesis, Cytosolic tRNA Thiolation and Cellular Bioenergetics in Human Embryonic Kidney Cells JF - Biomolecules N2 - Sulfur is an important element that is incorporated into many biomolecules in humans. The incorporation and transfer of sulfur into biomolecules is, however, facilitated by a series of different sulfurtransferases. Among these sulfurtransferases is the human mercaptopyruvate sulfurtransferase (MPST) also designated as tRNA thiouridine modification protein (TUM1). The role of the human TUM1 protein has been suggested in a wide range of physiological processes in the cell among which are but not limited to involvement in Molybdenum cofactor (Moco) biosynthesis, cytosolic tRNA thiolation and generation of H2S as signaling molecule both in mitochondria and the cytosol. Previous interaction studies showed that TUM1 interacts with the L-cysteine desulfurase NFS1 and the Molybdenum cofactor biosynthesis protein 3 (MOCS3). Here, we show the roles of TUM1 in human cells using CRISPR/Cas9 genetically modified Human Embryonic Kidney cells. Here, we show that TUM1 is involved in the sulfur transfer for Molybdenum cofactor synthesis and tRNA thiomodification by spectrophotometric measurement of the activity of sulfite oxidase and liquid chromatography quantification of the level of sulfur-modified tRNA. Further, we show that TUM1 has a role in hydrogen sulfide production and cellular bioenergetics. KW - Moco biosynthesis KW - sulfite oxidase KW - cytosolic tRNA thiolation KW - 5-methoxycarbonylmethyl-2-thiouridine KW - H2S biosynthesis KW - cellular bioenergetics Y1 - 2023 U6 - https://doi.org/10.3390/biom13010144 SN - 2218-273X VL - 13 SP - 1 EP - 23 PB - MDPI CY - Basel, Schweiz ET - 1 ER - TY - JOUR A1 - Marggraf, Lara Christin A1 - Lindecke, Oliver A1 - Voigt, Christian C. A1 - Pētersons, Gunārs A1 - Voigt-Heucke, Silke Luise T1 - Nathusius’ bats, Pipistrellus nathusii, bypass mating opportunities of their own species, but respond to foraging heterospecifics on migratory transit flights JF - Frontiers in Ecology and Evolution N2 - In late summer, migratory bats of the temperate zone face the challenge of accomplishing two energy-demanding tasks almost at the same time: migration and mating. Both require information and involve search efforts, such as localizing prey or finding potential mates. In non-migrating bat species, playback studies showed that listening to vocalizations of other bats, both con-and heterospecifics, may help a recipient bat to find foraging patches and mating sites. However, we are still unaware of the degree to which migrating bats depend on con-or heterospecific vocalizations for identifying potential feeding or mating opportunities during nightly transit flights. Here, we investigated the vocal responses of Nathusius’ pipistrelle bats, Pipistrellus nathusii, to simulated feeding and courtship aggregations at a coastal migration corridor. We presented migrating bats either feeding buzzes or courtship calls of their own or a heterospecific migratory species, the common noctule, Nyctalus noctula. We expected that during migratory transit flights, simulated feeding opportunities would be particularly attractive to bats, as well as simulated mating opportunities which may indicate suitable roosts for a stopover. However, we found that when compared to the natural silence of both pre-and post-playback phases, bats called indifferently during the playback of conspecific feeding sounds, whereas P. nathusii echolocation call activity increased during simulated feeding of N. noctula. In contrast, the call activity of P. nathusii decreased during the playback of conspecific courtship calls, while no response could be detected when heterospecific call types were broadcasted. Our results suggest that while on migratory transits, P. nathusii circumnavigate conspecific mating aggregations, possibly to save time or to reduce the risks associated with social interactions where aggression due to territoriality might be expected. This avoidance behavior could be a result of optimization strategies by P. nathusii when performing long-distance migratory flights, and it could also explain the lack of a response to simulated conspecific feeding. However, the observed increase of activity in response to simulated feeding of N. noctula, suggests that P. nathusii individuals may be eavesdropping on other aerial hawking insectivorous species during migration, especially if these occupy a slightly different foraging niche. KW - playback KW - phonotaxis KW - bats KW - acoustic communication KW - animal migration KW - eavesdropping KW - echolocation KW - Pipistrellus nathusii Y1 - 2023 U6 - https://doi.org/10.3389/fevo.2022.908560 SN - 2296-701X SP - 1 EP - 10 PB - Frontiers CY - Lausanne, Schweiz ER - TY - THES A1 - Artins, Anthony T1 - Crosstalk between Target Of Rapamycin (TOR) and sugar signaling in Arabidopsis thaliana Y1 - 2023 ER - TY - THES A1 - Amen, Rahma T1 - Adaptive radiation in African weakly electric fish genus Campylomormyrus BT - a behavior, ecological and morphological perspective N2 - The African weakly electric fish genus Campylomormyrus includes 15 described species mostly native to the Congo River and its tributaries. They are considered sympatric species, because their distribution area overlaps. These species generate species-specific electric organ discharges (EODs) varying in waveform characteristics, including duration, polarity, and phase number. They exhibit also pronounced divergence in their snout, i.e. the length, thickness, and curvature. The diversifications in these two phenotypical traits (EOD and snout) have been proposed as key factors promoting adaptive radiation in Campylomormyrus. The role of EODs as a pre-zygotic isolation mechanism driving sympatric speciation by promoting assortative mating has been examined using behavioral, genetical, and histological approaches. However, the evolutionary effects of the snout morphology and its link to species divergence have not been closely examined. Hence, the main objective of this study is to investigate the effect of snout morphology diversification and its correlated EOD to better understand their sympatric speciation and evolutionary drivers. Moreover, I aim to utilize the intragenus and intergenus hybrids of Campylomormyrus to better understand trait divergence as well as underlying molecular/genetic mechanisms involved in the radiation scenario. To this end, I utilized three different approaches: feeding behavior analysis, diet assessment, and geometric morphometrics analysis. I performed feeding behavior experiments to evaluate the concept of the phenotype-environment correlation by testing whether Campylomormyrus species show substrate preferences. The behavioral experiments showed that the short snout species exhibits preference to sandy substrate, the long snout species prefers a stone substrate, and the species with intermediate snout size does not exhibit any substrate preference. The experiments suggest that the diverse feeding apparatus in the genus Campylomormyrus may have evolved in adaptation to their microhabitats. I also performed diet assessments of sympatric Campylomormyrus species and a sister genus species (Gnathonemus petersii) with markedly different snout morphologies and EOD using NGS-based DNA metabarcoding of their stomach contents. The diet of each species was documented showing that aquatic insects such as dipterans, coleopterans and trichopterans represent the major diet component. The results showed also that all species are able to exploit diverse food niches in their habitats. However, comparing the diet overlap indices showed that different snout morphologies and the associated divergence in the EOD translated into different prey spectra. These results further support the idea that the EOD could be a ‘magic trait’ triggering both adaptation and reproductive isolation. Geometric morphometrics method was also used to compare the phenotypical shape traits of the F1 intragenus (Campylomormyrus) and intergenus (Campylomormyrus species and Gnathonemus petersii) hybrids relative to their parents. The hybrids of these species were well separated based on the morphological traits, however the hybrid phenotypic traits were closer to the short-snouted species. In addition, the likelihood that the short snout expressed in the hybrids increases with increasing the genetic distance of the parental species. The results confirmed that additive effects produce intermediate phenotypes in F1-hybrids. It seems, therefore, that morphological shape traits in hybrids, unlike the physiological traits, were not expressed straightforward. KW - adaptive radiation KW - ecological speciation KW - African weakly electric fish KW - trophic apparatus KW - DNA metabarcoding KW - geometric morphometric Y1 - 2023 ER -