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Aspects of the prevention of light damage during drying and rehydration of the desiccation-tolerant grass Eragrostis nindensis
There are two main mechanisms of desiccation-tolerance in angiosperms. Both of these (poikilochlorophylly and homoiochlorophylly) involve adaptations to prevent light-induced damage as the plants dry and rehydrate. The poikiolchlorophyllous grass E. nindensis was investigated to determine physiologi...
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| Format: | Thesis |
| Language: | English |
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Department of Biological Sciences
2017
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| _version_ | 1867613231409790976 |
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| access_status_str | Open Access |
| author | Bergh, Nicola G |
| author2 | Farrant, Jill M |
| author_browse | Bergh, Nicola G Farrant, Jill M |
| author_facet | Farrant, Jill M Bergh, Nicola G |
| author_sort | Bergh, Nicola G |
| collection | Thesis |
| description | There are two main mechanisms of desiccation-tolerance in angiosperms. Both of these (poikilochlorophylly and homoiochlorophylly) involve adaptations to prevent light-induced damage as the plants dry and rehydrate. The poikiolchlorophyllous grass E. nindensis was investigated to determine physiological responses to light during drying, and mechanisms of tolerance of dehydration. The desiccation-sensitive E. curvula was investigated simultaneously as a control in order to compare responses of tolerant and sensitive relatives. Quantum efficiency of photosystem II was determined using chlorophyll fluorescence parameters and levels of photosynthetic pigments (chlorophylls and carotenoids) and of anthocyanins were measured. Electrolyte leakage of drying and rehydrating leaves was monitored to determine the extent of damage to membranes. Quantum efficiency and photosynthetic pigment contents were reduced in both plant§ dehydrated to <2% RWC; only E. nindensis recovered to initial levels. Both plants accumulated anthocyanins but these reached greater levels in E. nindensis and were found on the entire length of the leaf. On rehydration, E. nindensis lost the anthocyanins as it reconstituted chlorophylls. Neither species showed marked increases in electrolyte leakage but E. curvula did not recover on rewatering. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/25780 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:32:51.499Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2017 |
| publishDateRange | 2017 |
| publishDateSort | 2017 |
| publisher | Department of Biological Sciences |
| publisherStr | Department of Biological Sciences |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/25780 Aspects of the prevention of light damage during drying and rehydration of the desiccation-tolerant grass Eragrostis nindensis Bergh, Nicola G Farrant, Jill M Botany There are two main mechanisms of desiccation-tolerance in angiosperms. Both of these (poikilochlorophylly and homoiochlorophylly) involve adaptations to prevent light-induced damage as the plants dry and rehydrate. The poikiolchlorophyllous grass E. nindensis was investigated to determine physiological responses to light during drying, and mechanisms of tolerance of dehydration. The desiccation-sensitive E. curvula was investigated simultaneously as a control in order to compare responses of tolerant and sensitive relatives. Quantum efficiency of photosystem II was determined using chlorophyll fluorescence parameters and levels of photosynthetic pigments (chlorophylls and carotenoids) and of anthocyanins were measured. Electrolyte leakage of drying and rehydrating leaves was monitored to determine the extent of damage to membranes. Quantum efficiency and photosynthetic pigment contents were reduced in both plant§ dehydrated to <2% RWC; only E. nindensis recovered to initial levels. Both plants accumulated anthocyanins but these reached greater levels in E. nindensis and were found on the entire length of the leaf. On rehydration, E. nindensis lost the anthocyanins as it reconstituted chlorophylls. Neither species showed marked increases in electrolyte leakage but E. curvula did not recover on rewatering. 2017-10-25T08:20:37Z 2017-10-25T08:20:37Z 1998 2017-02-23T06:58:28Z Bachelor Thesis Honours BSc (Hons) http://hdl.handle.net/11427/25780 eng application/pdf Department of Biological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Botany Bergh, Nicola G Aspects of the prevention of light damage during drying and rehydration of the desiccation-tolerant grass Eragrostis nindensis |
| thesis_degree_str | Bachelor's / Honours |
| title | Aspects of the prevention of light damage during drying and rehydration of the desiccation-tolerant grass Eragrostis nindensis |
| title_full | Aspects of the prevention of light damage during drying and rehydration of the desiccation-tolerant grass Eragrostis nindensis |
| title_fullStr | Aspects of the prevention of light damage during drying and rehydration of the desiccation-tolerant grass Eragrostis nindensis |
| title_full_unstemmed | Aspects of the prevention of light damage during drying and rehydration of the desiccation-tolerant grass Eragrostis nindensis |
| title_short | Aspects of the prevention of light damage during drying and rehydration of the desiccation-tolerant grass Eragrostis nindensis |
| title_sort | aspects of the prevention of light damage during drying and rehydration of the desiccation tolerant grass eragrostis nindensis |
| topic | Botany |
| url | http://hdl.handle.net/11427/25780 |
| work_keys_str_mv | AT berghnicolag aspectsofthepreventionoflightdamageduringdryingandrehydrationofthedesiccationtolerantgrasseragrostisnindensis |