Dokument: Identification of C4 genetic determinants by comparative transcriptomics and forward genetic approaches
| Titel: | Identification of C4 genetic determinants by comparative transcriptomics and forward genetic approaches | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=48243 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20190110-103251-6 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | M.Sc Billakurthi, Kumari [Autor] | |||||||
| Dateien: |
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| Beitragende: | Prof. Dr. Westhoff, Peter [Gutachter] Prof. Dr. Maria von Korff Schmising [Gutachter] | |||||||
| Stichwörter: | C4 photosynthesis | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 580 Pflanzen (Botanik) | |||||||
| Beschreibung: | C4 photosynthetic pathway is a coordinated evolution between development of Kranz leaf anatomy and division-of-labor i.e. spatial distribution of C4 cycle reactions within mesophyll and bundle sheath cells. However, for establishment of efficient C4 cycle, C4 Kranz anatomy is a prerequisite, which in-turn regulates the functional operation of the former. Therefore, in the presented study, two different approaches were chosen for identifying novel gene regulatory mechanisms underpinning C4 specific leaf development.
Transcriptome dataset and leaf anatomy of developmental leaf gradients from closely related C3 Flaveria robusta and C4 Flaveria bidentis was analyzed to distinguish the developmental progression of C3 and C4 leaves and to identify differentially expressed genes during C4 leaf development. Non-negative matrix factorization of the data discerned four different transcriptome patterns within the developing leaf of both the species. As expected, genes involved in Calvin-Benson-Bessham and photorespiration pathways were upregulated in C3 F. robusta while genes in the C4 cycle and cyclic electron transport complex were upregulated in C4 F. bidentis. Importantly, in both species, the expression of genes in these pathways peaks at a same developmental stage. Along with this, further, in both the species mesophyll and bundle sheath differentiation occurred at the same developmental stage as assessed via leaf anatomy. Strikingly, transcripts of auxin synthesis and auxin homeostasis related genes showed higher abundance in early C4 leaf development compared to F. robusta that might be further related to increased vein density in C4 F. bidentis and maybe one future aspect of the current study. To identify bundle sheath mutants, EMS mutagenesis and activation tagging genetic screens were performed on A. thaliana LUC and/or GFP reference line background. For this, primarily, several thousands of plants were screened based on reporter gene signal intensity with the further selection of mutant lines with deviated reporter signal intensity. In the following step, leaf anatomy of identified mutant lines was analyzed with light microscopy and transmission electron microscopy. With this approach, we could identify five EMS mutant lines with altered bundle sheath plus vascular tissue structure. Interestingly, the identified activation tagging bsom4 mutant line contains numerous plasmodesmata connections between all leaf tissue cells of A. thaliana. The unknown BSOM4 gene (bundle sheath ontogeny and morphology 4; AT1G29480) was proven to be responsible for the observed phenotype and this gene was further characterized in detail. | |||||||
| Lizenz: |  Urheberrechtsschutz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Biologie » Entwicklungs- und Molekularbiologie der Pflanzen | |||||||
| Dokument erstellt am: | 10.01.2019 | |||||||
| Dateien geändert am: | 10.01.2019 | |||||||
| Promotionsantrag am: | 14.09.2018 | |||||||
| Datum der Promotion: | 17.12.2018 |
