Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
A comparison of leaf sucrose accumulation and regulation between plants of C.Plantagineum dried in the light and dark
The resurrection plant C. plantagineum is able to survive almost complete water loss in their vegetative tissues and can then rehydrate rapidly on rewatering. The ability to recover completely from dehydration has been attributed in part to the ability of the plant to accumulate large quantities of...
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Biological Sciences
2017
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613344211402752 |
|---|---|
| access_status_str | Open Access |
| author | Rojoa, N Z |
| author2 | Farrant, Jill M |
| author_browse | Farrant, Jill M Rojoa, N Z |
| author_facet | Farrant, Jill M Rojoa, N Z |
| author_sort | Rojoa, N Z |
| collection | Thesis |
| description | The resurrection plant C. plantagineum is able to survive almost complete water loss in their vegetative tissues and can then rehydrate rapidly on rewatering. The ability to recover completely from dehydration has been attributed in part to the ability of the plant to accumulate large quantities of sucrose. The accumulation of sucrose stabilises membranes, protects proteins and contributes to cellular osmoregulation during water stress. However, it has been observed in C. wilmsii by research group of Farrant (unpublished) that sucrose accumulations differ significantly when dehydration is carried out in the light and the dark. Farrant (unpublished) observed a significant increase in sucrose accumulation when dehydration was carried in light while dehydration in the dark resulted in very low amount of sucrose. Based on these findings, using the plant C. plantagineum, metabolic factors, which could contribute to differences, observed in C. wilmsii for sucrose accumulation in both light and dark was examined in this project. To achieve this, three enzymes in relation to sucrose accumulation from leaves dried in both light and dark treatments were examined, namely: hexokinase, acid invertase and aldolase. The amount of glucose, fructose and sucrose during the dehydration process in both light and dark treatments were also examined. Results obtained show a significant decrease in sucrose (9.8-fold decrease) when tissues of C. plantagineum where dried in the dark as opposed to the light. Furthermore, the amount of hexose sugars was also significantly lower in dark dehydrated tissues. Moreover, the enzyme data for dark dehydrated samples showed that both aldolase and hexokinase activity levels were significantly low. In contrast, enzyme data for the light dehydrated tissues showed that aldolase and hexokinase activities were maintained, although a higher level of aldolase activity was recorded, until approximately 10% RWC where a drop-in activity was recorded for both enzyme. However, acid invertase activity was comparable for both light and dark dehydrated tissues. Thus, it seems that the down regulation of aldolase during dehydration in the dark might be responsible for the low sucrose content obtained in the dark for C. plantagineum. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/26097 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:34:39.078Z |
| 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:11427/26097 A comparison of leaf sucrose accumulation and regulation between plants of C.Plantagineum dried in the light and dark Rojoa, N Z Farrant, Jill M Botany The resurrection plant C. plantagineum is able to survive almost complete water loss in their vegetative tissues and can then rehydrate rapidly on rewatering. The ability to recover completely from dehydration has been attributed in part to the ability of the plant to accumulate large quantities of sucrose. The accumulation of sucrose stabilises membranes, protects proteins and contributes to cellular osmoregulation during water stress. However, it has been observed in C. wilmsii by research group of Farrant (unpublished) that sucrose accumulations differ significantly when dehydration is carried out in the light and the dark. Farrant (unpublished) observed a significant increase in sucrose accumulation when dehydration was carried in light while dehydration in the dark resulted in very low amount of sucrose. Based on these findings, using the plant C. plantagineum, metabolic factors, which could contribute to differences, observed in C. wilmsii for sucrose accumulation in both light and dark was examined in this project. To achieve this, three enzymes in relation to sucrose accumulation from leaves dried in both light and dark treatments were examined, namely: hexokinase, acid invertase and aldolase. The amount of glucose, fructose and sucrose during the dehydration process in both light and dark treatments were also examined. Results obtained show a significant decrease in sucrose (9.8-fold decrease) when tissues of C. plantagineum where dried in the dark as opposed to the light. Furthermore, the amount of hexose sugars was also significantly lower in dark dehydrated tissues. Moreover, the enzyme data for dark dehydrated samples showed that both aldolase and hexokinase activity levels were significantly low. In contrast, enzyme data for the light dehydrated tissues showed that aldolase and hexokinase activities were maintained, although a higher level of aldolase activity was recorded, until approximately 10% RWC where a drop-in activity was recorded for both enzyme. However, acid invertase activity was comparable for both light and dark dehydrated tissues. Thus, it seems that the down regulation of aldolase during dehydration in the dark might be responsible for the low sucrose content obtained in the dark for C. plantagineum. 2017-11-09T10:42:15Z 2017-11-09T10:42:15Z 2002 2017-03-07T12:53:59Z Bachelor Thesis Honours BSc (Hons) http://hdl.handle.net/11427/26097 eng application/pdf Department of Biological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Botany Rojoa, N Z A comparison of leaf sucrose accumulation and regulation between plants of C.Plantagineum dried in the light and dark |
| thesis_degree_str | Bachelor's / Honours |
| title | A comparison of leaf sucrose accumulation and regulation between plants of C.Plantagineum dried in the light and dark |
| title_full | A comparison of leaf sucrose accumulation and regulation between plants of C.Plantagineum dried in the light and dark |
| title_fullStr | A comparison of leaf sucrose accumulation and regulation between plants of C.Plantagineum dried in the light and dark |
| title_full_unstemmed | A comparison of leaf sucrose accumulation and regulation between plants of C.Plantagineum dried in the light and dark |
| title_short | A comparison of leaf sucrose accumulation and regulation between plants of C.Plantagineum dried in the light and dark |
| title_sort | comparison of leaf sucrose accumulation and regulation between plants of c plantagineum dried in the light and dark |
| topic | Botany |
| url | http://hdl.handle.net/11427/26097 |
| work_keys_str_mv | AT rojoanz acomparisonofleafsucroseaccumulationandregulationbetweenplantsofcplantagineumdriedinthelightanddark AT rojoanz comparisonofleafsucroseaccumulationandregulationbetweenplantsofcplantagineumdriedinthelightanddark |