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Unraveling uranium induced oxidative stress related responses in Arabidopsis thaliana seedlings. Part I: responses in the roots.
- Source :
-
Journal of environmental radioactivity [J Environ Radioact] 2011 Jun; Vol. 102 (6), pp. 630-7. Date of Electronic Publication: 2011 Apr 13. - Publication Year :
- 2011
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Abstract
- When aiming to evaluate the environmental impact of uranium contamination, it is important to unravel the mechanisms by which plants respond to uranium stress. As oxidative stress seems an important modulator under other heavy metal stress, this study aimed to investigate oxidative stress related responses in Arabidopsis thaliana exposed to uranium concentrations ranging from 0.1 to 100 μM for 1, 3 and 7 days. Besides analyzing relevant reactive oxygen species-producing and -scavenging enzymes at protein and transcriptional level, the importance of the ascorbate-glutathione cycle under uranium stress was investigated. These results are reported separately for roots and leaves in two papers: Part I dealing with responses in the roots and Part II unraveling responses in the leaves and presenting general conclusions. Results of Part I indicate that oxidative stress related responses in the roots were only triggered following exposure to the highest uranium concentration of 100 μM. A fast oxidative burst was suggested based on the observed enhancement of lipoxygenase (LOX1) and respiratory burst oxydase homolog (RBOHD) transcript levels already after 1 day. The first line of defense was attributed to superoxide dismutase (SOD), also triggered from the first day. The enhanced SOD-capacity observed at protein level corresponded with an enhanced expression of iron SOD (FSD1) located in the plastids. For the detoxification of H(2)O(2), an early increase in catalase (CAT1) transcript levels was observed while peroxidase capacities were enhanced at the later stage of 3 days. Although the ascorbate peroxidase capacity and gene expression (APX1) increased, the ascorbate/dehydroascorbate redox balance was completely disrupted and shifted toward the oxidized form. This disrupted balance could not be inverted by the glutathione part of the cycle although the glutathione redox balance could be maintained.<br /> (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Subjects :
- Arabidopsis drug effects
Arabidopsis growth & development
Ascorbic Acid metabolism
Gene Expression
Glutathione metabolism
Hydrogen Peroxide metabolism
Oxidation-Reduction
Oxidoreductases metabolism
Plant Roots drug effects
Plant Roots growth & development
Plant Roots metabolism
Radiation Dosage
Reactive Oxygen Species metabolism
Seedlings drug effects
Seedlings growth & development
Seedlings metabolism
Antioxidants metabolism
Arabidopsis metabolism
Arabidopsis Proteins metabolism
Oxidative Stress
Uranium toxicity
Subjects
Details
- Language :
- English
- ISSN :
- 1879-1700
- Volume :
- 102
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Journal of environmental radioactivity
- Publication Type :
- Academic Journal
- Accession number :
- 21492976
- Full Text :
- https://doi.org/10.1016/j.jenvrad.2011.03.015