Dokument: Transcriptomic and genetic studies of leaf development in the C4 monocot Sorghum bicolor and the C3 dicot Arabidopsis thaliana
| Titel: | Transcriptomic and genetic studies of leaf development in the C4 monocot Sorghum bicolor and the C3 dicot Arabidopsis thaliana | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=61492 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20221220-091329-5 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Bano, Zahida [Autor] | |||||||
| Dateien: |
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| Beitragende: | Prof. Dr. Westhoff, Peter [Gutachter] Prof. Dr. Maria von Korff Schmising [Gutachter] | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 570 Biowissenschaften; Biologie | |||||||
| Beschreibung: | Leaf morphogenesis is a crucial process for a plant to adjust the cellular arrangement of photosynthetic tissue in an optimized way to improve photosynthetic activity. During evolution, leaves of C3 plants underwent a few anatomical and cellular adaptations to acquire C4 anatomy. The changes include the development of Kranz anatomy, enlargement of mesophyll (M) and bundle sheath size (BS), increased number of chloroplasts in BS cells, enrichment of plasmodesmata between M and BS cell to facilitate metabolic exchange, followed by compartmentation of CO2 assimilation and fixation by increasing PEPC activity in the M cell and Rubisco in the BS chloroplast. To identify novel regulators underpinning C4-specific leaf development, in this study, we presented two different approaches.
In the first approach, we analyzed leaf anatomy and transcriptome dataset of etiolated and illuminated Sorghum seedlings using light as a trigger of leaf development. We observed that the leaf development in Sorghum is arrested in the dark because, during etiolation, the leaves remained pale and enclosed in the coleoptile. Leaves emergence and greening were observed only after light exposure. Transcriptome data analysis showed a strong correlation between leaf development and chloroplast biogenesis in Sorghum. Genes involved in chloroplast development and differentiation, assembly of photosynthetic apparatus and C4 cycle genes showed light-induced accumulation. Moreover, genes involved in various pathways do not accumulate sequentially but rather coordinately. More interestingly, the nuclear-encoded genes expressed at early exposure, while plastid-encoded genes required a longer exposure time. In the second approach, numerous BS mutants were produced using a forward genetic screen of EMS-induced mutant lines in Arabidopsis thaliana using a bundle sheath labelled with GFP reporter genes. The BS mutants were selected based on the altered reporter gene signal intensity and hypothesized that the altered signal intensity of the BS could be due to changes in BS numbers and/or chloroplast inside the BS cells. By pursuing a mapping-by-sequencing approach, the genomic segments containing mutated candidate genes were identified. Two EMS-induced mutant lines, ebss1 (high reporter genes signal in the BS cell) and fbss1 (low reporter genes signal in the BS cell), were selected for further investigation to identify the putative genes responsible for ebss1 and fbss1 mutant phenotype. By pursuing CRISPR/Cas9-induced genetic modification of candidate genes, it was revealed that the mutant allele of At2g25970 was responsible for high GFP signals in ebss1 BS cells and the elevated GFP signal intensity was due to an increased number of BS cells. Furthermore, At5g04940 (SUVH1) was proven to be a responsible gene for the fbss1 mutant phenotype. | |||||||
| Lizenz: |  Dieses Werk ist lizenziert unter einer Creative Commons Namensnennung 4.0 International Lizenz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Biologie » Entwicklungs- und Molekularbiologie der Pflanzen | |||||||
| Dokument erstellt am: | 20.12.2022 | |||||||
| Dateien geändert am: | 20.12.2022 | |||||||
| Promotionsantrag am: | 09.08.2022 | |||||||
| Datum der Promotion: | 28.11.2022 |
