Investigating the mechanisms of desiccation tolerance in the resurrection plant, myrothamnus flabellifolius (WELW)
type: CreativeWork
description: Resurrection plants, including Myrothamnus flabellifolius, grow in shallow soil upon rocky outcrops where they experience regular periods of water stress. Associated with this is light stress. The presence of light under water limiting conditions can result in photo-oxidation which causes damage to plant tissues. M flabellifolius is a homoichlorophyllous plant and thus retains chlorophyll during desiccation. The mechanisms whereby this plant prevents photo-oxidation damage are not known and thus one of the objectives of this study was to characterise the chloroplasts and the changes they undergo during dehydration. It was shown that chloroplasts from M flabellifolius could only be isolated using trehalose gradients (instead of sucrose gradients) and were found to have a higher buoyant density than chloroplasts isolated from another resurrection plant, Craterostigma wilmsii. The latter had the same buoyant density as those isolated from the desiccation sensitive plant Pisum sativum. The increased buoyant density in M flabellifolius was ascribed to the unusual ultrastructure of the thylakoid membranes. The latter have a staggered conformation (staircase arrangement) rather than the discrete granal and intergranal conformation found in most plants.
abstract: Resurrection plants, including Myrothamnus flabellifolius, grow in shallow soil upon rocky outcrops where they experience regular periods of water stress. Associated with this is light stress. The presence of light under water limiting conditions can result in photo-oxidation which causes damage to plant tissues. M flabellifolius is a homoichlorophyllous plant and thus retains chlorophyll during desiccation. The mechanisms whereby this plant prevents photo-oxidation damage are not known and thus one of the objectives of this study was to characterise the chloroplasts and the changes they undergo during dehydration. It was shown that chloroplasts from M flabellifolius could only be isolated using trehalose gradients (instead of sucrose gradients) and were found to have a higher buoyant density than chloroplasts isolated from another resurrection plant, Craterostigma wilmsii. The latter had the same buoyant density as those isolated from the desiccation sensitive plant Pisum sativum. The increased buoyant density in M flabellifolius was ascribed to the unusual ultrastructure of the thylakoid membranes. The latter have a staggered conformation (staircase arrangement) rather than the discrete granal and intergranal conformation found in most plants.
author: Koonjul, Priyum K
language: eng
date published: 1999
date modified: 2026-07-22T22:23:23Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Molecular and Cell Biology

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/9940