Dokument: Characterization of the infection process in rice bacterial blight by Xanthomonas oryzae pv. oryzae
| Titel: | Characterization of the infection process in rice bacterial blight by Xanthomonas oryzae pv. oryzae | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=72873 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20260413-080432-7 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Zöllner, Nora Rachel [Autor] | |||||||
| Dateien: |
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| Beitragende: | Prof. Dr. Frommer, Wolf B. [Betreuer/Doktorvater] Prof. Dr. Feldbrügge, Michael [Gutachter] Prof. Dr. Peck, Scott C. [Gutachter] | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 570 Biowissenschaften; Biologie | |||||||
| Beschreibung: | Bacterial blight (BB) of rice, caused by the bacterium Xanthomonas oryzae pv. oryzae (Xoo), is one of the most destructive plant diseases worldwide. Bacterial Blight is responsible for major losses in the production of the staple crop. The pathogen colonizes the xylem vasculature, a nutrient-scarce environment with continuous sap flow. Therefore, the pathogen manipulates the host metabolism to secure access to carbon resources. One key strategy for achieving this is the deployment of transcription activator-like (TAL) effectors, which induce the expression of clade III SWEET sucrose transporters in rice. Hijacking of SWEETs leads to sucrose efflux
into the apoplasm. This pathogen-induced reallocation of carbohydrate flux creates a nutrient source that supports the proliferation of Xoo and the development of disease. This thesis examines the mechanisms by which Xoo acquires and metabolizes host-derived sucrose. A conserved sux gene cluster was identified that mediates sucrose uptake and utilization. Functional, structural, and kinetic analyses revealed that SuxB is a GH13-4 sucrose hydrolase with high catalytic efficiency. Evidence for a secreted isoform indicate that SuxB is targeted to both the intracellular and extracellular space, which may expand hydrolytic capacity or support cooperative bacterial growth. These findings establish the sux cluster as a central determinant of sucrose acquisition and connect TAL effector–mediated host manipulation directly to pathogen metabolism. Dual transcriptomic analyses show a parallel increase of SWEET and sux transcripts, indicating that bacterial sucrose uptake is temporally coordinated with host sucrose efflux. Additionally, the ability of Xoo to colonize the xylem against the direction of sap flow was investigated using hydrodynamic modeling, microfluidic devices, and adapted infection assays. Finally, novel Matryoshka-based biosensors for sucrose and glucose were developed which provide tools for monitoring sugar dynamics in host–pathogen interactions. By connecting host sucrose release to bacterial metabolic capacity and colonization dynamics, this thesis provides mechanistic insight into the Xoo infection process and establishes a framework for resistance strategies targeting pathogen access to host sugars. | |||||||
| Lizenz: |  Dieses Werk ist lizenziert unter einer Creative Commons Namensnennung 4.0 International Lizenz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Biologie | |||||||
| Dokument erstellt am: | 13.04.2026 | |||||||
| Dateien geändert am: | 13.04.2026 | |||||||
| Promotionsantrag am: | 23.09.2025 | |||||||
| Datum der Promotion: | 02.04.2026 |
