Dokument: Identification and functional characterization of ICS1-dependent metabolites in Arabidopsis thaliana (L.) HEYNH.
| Titel: | Identification and functional characterization of ICS1-dependent metabolites in Arabidopsis thaliana (L.) HEYNH. | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=58583 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20240321-095529-1 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Scholten, Nicola [Autor] | |||||||
| Dateien: |
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| Beitragende: | Prof. Dr. Zeier, Jürgen [Gutachter] Prof. Dr. Groth, Georg [Gutachter] | |||||||
| Stichwörter: | salicylic acid, isochorismate, plant pathology, NHP, plant immunity, Arabidopsis thaliana | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 580 Pflanzen (Botanik) | |||||||
| Beschreibung: | To combat pathogens, plants have evolved a multi-layered immune system which is based on a complex signaling network controlled by plant hormones and defense-related metabolites. Comparative metabolite-profiling with leaf extracts of Pseudomonas syringae (Psm) inoculated and uninfected Arabidopsis thaliana plants indicate that more than 100, partially uncharacterized, metabolites with a potential function in plant immunity accumulate in leaves upon pathogen challenge. Crucial defense-regulatory metabolites include the phytohormone salicylic acid (SA) and the hydroxylated non-proteinogenic amino acid N-hydroxypipecolic acid (NHP) and its precursor pipecolic acid (Pip). In this study, we extended the hitherto described isochorismate pathway by nine previously unknown molecular species. The results were achieved using a combination of gas chromatography with mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (GC-FTIR). Combining the analytical and spectroscopic data, the chemical structures of the molecular species were reconstructed and identified. The identity of most molecular species was proven by authentic standard substances or chemical synthesis. With SA-Mal we discovered and identified a novel SA derivative in planta. However, the involvement of SA-Mal in plant immunity remains to be investigated. Moreover, we proved ICS1 and PBS3 dependency of isochorismoyl-Glu and N pyruvoyl-Glu and thereby underlined the central involvement of PBS3 in SA biosynthesis and plant defense, in agreement with latest research results. Besides the high pathogen-dependent accumulation of all identified molecular species, the remaining six molecular species, 3 formylbenzoic acid, 5-formylsalicylic acid, 3 carboxybenzoic acid, 5-carboxysalicylic acid, 3 (carboxymethyl)-benzoic acid, and 5 (carboxymethyl)-salicylic acid, revealed no severe influence on plant immunity. Since we could prove that none of the six molecular species share a common origin with SA and BA, we propose that isoprephenic acid and 3-carboxyphenylpyruvate describe the missing link to fit all six molecular species into the isochorismate pathway. The transgenic NahG line has been established to study SA-dependent defense in A. thaliana. Our data indicates that the introduced SA-hydroxylase, also severely influences the NHP and Pip metabolism and has broader involvement to plant immunity than previously assumed. Whether NAHG directly accepts and hydroxylases NHP and Pip is one important goal to achieve in the future. Overall, the results of this study contribute to unravel the complex metabolic reprogramming induced in plants upon pathogen inoculation and identify novel regulatory metabolites in plant immunity. | |||||||
| Lizenz: |  Urheberrechtsschutz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Biologie » Ökologische Pflanzenphysiologie | |||||||
| Dokument erstellt am: | 21.03.2024 | |||||||
| Dateien geändert am: | 21.03.2024 | |||||||
| Promotionsantrag am: | 06.05.2021 | |||||||
| Datum der Promotion: | 28.10.2021 |
