@phdthesis{Lambour2023,
  author    = {Lambour, Benjamin},
  title     = {Regulation of sphingolipid long-chain bases during cell death reactions and abiotic stress in \(Arabidopsis\) \(thaliana\)},
  doi       = {10.25972/OPUS-32591},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325916},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Sphingobasen (LCBs) sind die Bausteine der Biosynthese von Sphingolipiden. Sie werden als Strukturelemente der pflanzlichen Zellmembran definiert und spielen eine wichtige Rolle f{\"u}r das Schicksal der Zellen. Komplexe Ceramide machen einen wesentlichen Teil der gesamten Sphingolipide aus, die einen großen Teil der eukaryotischen Membranen bilden. Gleichzeitig sind LCBs bekannte Signalmolek{\"u}le f{\"u}r zellul{\"a}re Prozesse in Eukaryonten und sind an Signal{\"u}bertragungswegen in Pflanzen beteiligt. Es hat sich gezeigt, dass hohe LCB-Konzentrationen mit der Induktion des programmierten Zelltods sowie mit dem durch Pathogene ausgel{\"o}sten Zelltod in Verbindung stehen. Mehrere Studien haben die regulierende Funktion der Sphingobasen beim programmierten Zelltod (PCD) in Pflanzen best{\"a}tigt: (i) Spontaner PCD und ver{\"a}nderte Zelltodreaktionen, die durch mutierte verwandte Gene des Sphingobasen-Stoffwechsels verursacht werden. (ii) Zelltodbedingungen erh{\"o}hen den Gehalt an LCBs. (iii) PCD aufgrund eines gest{\"o}rten Sphingolipid-Stoffwechsels, der durch von nekrotrophen Krankheitserregern produzierte Toxine wie Fumonisin B1 (FB1) hervorgerufen wird. Um den Zelltod zu verhindern und die Zelltodreaktion zu kontrollieren, kann daher die Regulierung des Gehalts an freien LCBs entscheidend sein. Die Ergebnisse der vorliegenden Studie stellten das Verst{\"a}ndnis der Sphingobasen und Sphingolipidspiegel w{\"a}hrend der PCD in Frage. Wir lieferten eine detaillierte Analyse der Sphingolipidspiegel, die Zusammenh{\"a}nge zwischen bestimmten Sphingolipidarten und dem Zelltod aufzeigte. Dar{\"u}ber hinaus erm{\"o}glichte uns die Untersuchung der Sphingolipid-Biosynthese ein Verst{\"a}ndnis des Fluxes nach Akkumulation hoher LCB-Konzentrationen. Weitere Analysen von Abbauprodukten oder Sphingolipid-Mutantenlinien w{\"a}ren jedoch erforderlich, um vollst{\"a}ndig zu verstehen, wie die Pflanze mit hohen Mengen an Sphingobasen umgeht.},
  subject      = {Ackerschmalwand},
  language  = {en}
}
@article{GhirardoNosenkoKreuzwieseretal.2021,
  author    = {Ghirardo, Andrea and Nosenko, Tetyana and Kreuzwieser, J{\"u}rgen and Winkler, J. Barbro and Kruse, J{\"o}rg and Albert, Andreas and Merl-Pham, Juliane and Lux, Thomas and Ache, Peter and Zimmer, Ina and Alfarraj, Saleh and Mayer, Klaus F. X. and Hedrich, Rainer and Rennenberg, Heinz and Schnitzler, J{\"o}rg-Peter},
  title     = {Protein expression plasticity contributes to heat and drought tolerance of date palm},
  series = {Oecologia},
  volume    = {197},
  journal   = {Oecologia},
  number    = {4},
  issn      = {0029-8549},
  doi       = {10.1007/s00442-021-04907-w},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-308075},
  pages     = {903-919},
  year      = {2021},
  abstract  = {Climate change is increasing the frequency and intensity of warming and drought periods around the globe, currently representing a threat to many plant species. Understanding the resistance and resilience of plants to climate change is, therefore, urgently needed. As date palm (Phoenix dactylifera) evolved adaptation mechanisms to a xeric environment and can tolerate large diurnal and seasonal temperature fluctuations, we studied the protein expression changes in leaves, volatile organic compound emissions, and photosynthesis in response to variable growth temperatures and soil water deprivation. Plants were grown under controlled environmental conditions of simulated Saudi Arabian summer and winter climates challenged with drought stress. We show that date palm is able to counteract the harsh conditions of the Arabian Peninsula by adjusting the abundances of proteins related to the photosynthetic machinery, abiotic stress and secondary metabolism. Under summer climate and water deprivation, these adjustments included efficient protein expression response mediated by heat shock proteins and the antioxidant system to counteract reactive oxygen species formation. Proteins related to secondary metabolism were downregulated, except for the P. dactylifera isoprene synthase (PdIspS), which was strongly upregulated in response to summer climate and drought. This study reports, for the first time, the identification and functional characterization of the gene encoding for PdIspS, allowing future analysis of isoprene functions in date palm under extreme environments. Overall, the current study shows that reprogramming of the leaf protein profiles confers the date palm heat- and drought tolerance. We conclude that the protein plasticity of date palm is an important mechanism of molecular adaptation to environmental fluctuations.},
  language  = {en}
}
@phdthesis{EscalantePerez2010,
  author    = {Escalante Perez, Maria},
  title     = {Poplar responses to biotic and abiotic stress},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-46893},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {In this study poplar trees have been examined under different stress conditions. Apart from the detailed descriptions above two main conclusions might be drawn: i) A small plant like Arabidopsis thaliana is highly susceptible to stress situations that might become life-threatening compared to a tree that has extremely more biomass at its disposal. Such an organism might be able to compensate severe stress much longer than a smaller one. It seems therefore reasonable that a crop like Arabidopsis reacts earlier and faster to a massive threat. ii) In poplar both tested stress responses seemed to be regulated by hormones. The reactions to abiotic salt stress are mainly controlled by ABA, which also has a strong impact upon cold and drought stress situations. The term commonly used for ABA is "stress hormone" and is at least applicable to all abiotic stresses. In case of herbivory (biotic stress), jasmonic acid appears to be the key-player that coordinates the defence mechanism underlying extrafloral nectary and nectar production. Thus the presented work has gained a few more insights into the complex network of general stress induced processes of poplar trees. Future studies will help to understand the particular role of the intriguing indirect defence system of the extrafloral nectaries in more detail.},
  subject      = {abiotic stress},
  language  = {en}
}