Back to Search
Start Over
Unraveling uranium induced oxidative stress related responses in Arabidopsis thaliana seedlings. Part II: responses in the leaves and general conclusions.
- Source :
-
Journal of environmental radioactivity [J Environ Radioact] 2011 Jun; Vol. 102 (6), pp. 638-45. Date of Electronic Publication: 2011 Apr 15. - Publication Year :
- 2011
-
Abstract
- The cellular redox balance seems an important modulator under heavy metal stress. While for other heavy metals these processes are well studied, oxidative stress related responses are also known to be triggered under uranium stress but information remains limited. This study aimed to further unravel the mechanisms by which plants respond to uranium stress. Seventeen-day-old Arabidopsis thaliana seedlings, grown on a modified Hoagland solution under controlled conditions, were exposed to 0, 0.1, 1, 10 and 100 μM uranium for 1, 3 and 7 days. While in Part I of this study oxidative stress related responses in the roots were discussed, this second Part II discusses oxidative stress related responses in the leaves and general conclusions drawn from the results of the roots and the leaves will be presented. As several responses were already visible following 1 day exposure, when uranium concentrations in the leaves were negligible, a root-to-shoot signaling system was suggested in which plastids could be important sensing sites. While lipid peroxidation, based on the amount of thiobarbituric acid reactive compounds, was observed after exposure to 100 μM uranium, affecting membrane structure and function, a transient concentration dependent response pattern was visible for lipoxygenase initiated lipid peroxidation. This transient character of uranium stress responses in leaves was emphasized by results of lipoxygenase (LOX2) and antioxidative enzyme transcript levels, enzyme capacities and glutathione concentrations both in time as with concentration. The ascorbate redox balance seemed an important modulator of uranium stress responses in the leaves as in addition to the previous transient responses, the total ascorbate concentration and ascorbate/dehydroascorbate redox balance increased in a concentration and time dependent manner. This could represent either a slow transient response or a stable increase with regard to plant acclimation to uranium stress.<br /> (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Subjects :
- Antioxidants metabolism
Arabidopsis drug effects
Arabidopsis growth & development
Ascorbic Acid metabolism
Gene Expression
Glutathione metabolism
Hydrogen Peroxide metabolism
Lipid Peroxidation
Oxidation-Reduction
Oxidoreductases metabolism
Plant Leaves drug effects
Plant Leaves growth & development
Plant Leaves 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
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 :
- 21497426
- Full Text :
- https://doi.org/10.1016/j.jenvrad.2011.03.013