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Modification of reactive oxygen species scavenging capacity of chloroplasts through plastid transformation
Poage, Miranda; Le Martret, Benedicte; Jansen, Marcel A.K.; Nugent, Gregory; Dix, Philip
Reactive oxygen species (ROS), including superoxide anions, hydrogen peroxide and hydroxyl radicals are generated through normal biochemical processes, but their production is increased by abiotic stresses. The prospects for enhancing ROS scavenging, and hence stress tolerance, by direct gene expression in a vulnerable cell compartment, the chloroplast, have been explored in tobacco. Several plastid transformants were generated which contained either a Nicotiana mitochondrial superoxide dismutase (MnSOD) or an Escherichia coli glutathione reductase (gor) gene. MnSOD lines had a three-fold increase in MnSOD activity, but interestingly a five to nine-fold increase in total chloroplast SOD activity. Gor transgenic lines had up to 6 times higher GR activity and up to 8 times total glutathione levels compared to wild type tobacco. Photosynthetic capacity of transplastomic plants, as measured by chlorophyll content and variable fluorescence of PSII was equivalent to non-transformed plants. The response of these transplastomic lines to several applied stresses was examined. In a number of cases improved stress tolerance was observed. Examples include enhanced methyl viologen (Paraquat)-induced oxidative stress tolerance in Mn-superoxidase dismutase overexpressing plants, improved heavy metal tolerance in glutathione reductase expressing lines, and improved tolerance to UV-B radiation in both sets of plants.
Keyword(s): Chloroplast transformation; Superoxide dismutase; Glutathione reductase; Abiotic stress
Publication Date:
Type: Journal article
Peer-Reviewed: Yes
Institution: Maynooth University
Citation(s): Poage, Miranda and Le Martret, Benedicte and Jansen, Marcel A.K. and Nugent, Gregory and Dix, Philip (2011) Modification of reactive oxygen species scavenging capacity of chloroplasts through plastid transformation. Plant Molecular Biology, 76 (3). pp. 371-384. ISSN 0167-4412
Publisher(s): Springer
File Format(s): other
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First Indexed: 2016-08-25 05:00:45 Last Updated: 2018-09-04 06:11:36