Dry and back again: characterization of desiccation-associated differentiation of leaf tissues in Craterostigma pumilum Hochst
| dc.contributor.advisor | Farrant, Jill Margaret | |
| dc.contributor.advisor | Reich, Ziv | |
| dc.contributor.author | Du Toit, Stephanus Francois | |
| dc.date.accessioned | 2023-09-08T11:52:08Z | |
| dc.date.available | 2023-09-08T11:52:08Z | |
| dc.date.issued | 2023 | |
| dc.date.updated | 2023-09-08T11:44:39Z | |
| dc.description.abstract | Resurrection plants are a polyphyletic group of angiosperms which display true desiccation tolerance - the ability to survive near complete loss of cellular water for extended periods, while recovering metabolic competence upon watering. This is achieved by employing tailored protection behaviours depending on the relative state of (de)hydration. Recent work has raised interest in desiccation associated changes related to tissue destiny in desiccation tolerant vegetative tissues. In this thesis, physiological and transcriptomic techniques were used to characterize such a phenomenon in the homoiochlorophyllous dicot resurrection plant Craterostigma pumilum. Detailed phenotypic observation and pulse-amplitude-modulation fluorometry were used to identify the critical water contents at which key physiological changes occur in leaves of C. pumilum and how this relates to desiccation-associated differentiation between leaf Tip and Base tissues. This was followed by transcriptomic analyses and comparison between these two tissues, to identify potentially key processes involved in desiccation associated tissue differentiation. All findings were then synthesised with existing information reported on for other resurrection plant species to create a theoretical model of desiccation-associated tissue differentiation. This differentiation phenomenon is shown to be transcriptionally initiated during the desiccation commitment stage of the C. pumilum dehydration cycle but is only realised phenotypically during early rehydration and after initial water movement through the leaf tissues. This work provides strong evidence for the existence of desiccation-associated tissue differentiation in C. pumilum and highlights the potential involvement of the phytohormone auxin in the determination of leaf tissue responses to progressive dehydration and anhydrobiosis in resurrection plants. | |
| dc.identifier.apacitation | Du Toit, S. F. (2023). <i>Dry and back again: characterization of desiccation-associated differentiation of leaf tissues in Craterostigma pumilum Hochst</i>. (). ,Faculty of Science ,Department of Molecular and Cell Biology. Retrieved from http://hdl.handle.net/11427/38471 | en_ZA |
| dc.identifier.chicagocitation | Du Toit, Stephanus Francois. <i>"Dry and back again: characterization of desiccation-associated differentiation of leaf tissues in Craterostigma pumilum Hochst."</i> ., ,Faculty of Science ,Department of Molecular and Cell Biology, 2023. http://hdl.handle.net/11427/38471 | en_ZA |
| dc.identifier.citation | Du Toit, S.F. 2023. Dry and back again: characterization of desiccation-associated differentiation of leaf tissues in Craterostigma pumilum Hochst. . ,Faculty of Science ,Department of Molecular and Cell Biology. http://hdl.handle.net/11427/38471 | en_ZA |
| dc.identifier.ris | TY - Doctoral Thesis AU - Du Toit, Stephanus Francois AB - Resurrection plants are a polyphyletic group of angiosperms which display true desiccation tolerance - the ability to survive near complete loss of cellular water for extended periods, while recovering metabolic competence upon watering. This is achieved by employing tailored protection behaviours depending on the relative state of (de)hydration. Recent work has raised interest in desiccation associated changes related to tissue destiny in desiccation tolerant vegetative tissues. In this thesis, physiological and transcriptomic techniques were used to characterize such a phenomenon in the homoiochlorophyllous dicot resurrection plant Craterostigma pumilum. Detailed phenotypic observation and pulse-amplitude-modulation fluorometry were used to identify the critical water contents at which key physiological changes occur in leaves of C. pumilum and how this relates to desiccation-associated differentiation between leaf Tip and Base tissues. This was followed by transcriptomic analyses and comparison between these two tissues, to identify potentially key processes involved in desiccation associated tissue differentiation. All findings were then synthesised with existing information reported on for other resurrection plant species to create a theoretical model of desiccation-associated tissue differentiation. This differentiation phenomenon is shown to be transcriptionally initiated during the desiccation commitment stage of the C. pumilum dehydration cycle but is only realised phenotypically during early rehydration and after initial water movement through the leaf tissues. This work provides strong evidence for the existence of desiccation-associated tissue differentiation in C. pumilum and highlights the potential involvement of the phytohormone auxin in the determination of leaf tissue responses to progressive dehydration and anhydrobiosis in resurrection plants. DA - 2023_ DB - OpenUCT DP - University of Cape Town KW - Leaf Tissues KW - Craterostigma pumilum Hochst LK - https://open.uct.ac.za PY - 2023 T1 - Dry and back again: characterization of desiccation-associated differentiation of leaf tissues in Craterostigma pumilum Hochst TI - Dry and back again: characterization of desiccation-associated differentiation of leaf tissues in Craterostigma pumilum Hochst UR - http://hdl.handle.net/11427/38471 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/38471 | |
| dc.identifier.vancouvercitation | Du Toit SF. Dry and back again: characterization of desiccation-associated differentiation of leaf tissues in Craterostigma pumilum Hochst. []. ,Faculty of Science ,Department of Molecular and Cell Biology, 2023 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/38471 | en_ZA |
| dc.language.rfc3066 | eng | |
| dc.publisher.department | Department of Molecular and Cell Biology | |
| dc.publisher.faculty | Faculty of Science | |
| dc.subject | Leaf Tissues | |
| dc.subject | Craterostigma pumilum Hochst | |
| dc.title | Dry and back again: characterization of desiccation-associated differentiation of leaf tissues in Craterostigma pumilum Hochst | |
| dc.type | Doctoral Thesis | |
| dc.type.qualificationlevel | Doctoral | |
| dc.type.qualificationlevel | PhD |