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A modulating role for antioxidants in desiccation tolerance.
1Seed Conservation Department, Royal Botanic Gardens, Kew, Wakehurst Place, West Sussex RH17 6TN, United Kingdom.
Integrative and Comparative Biology
|June 17, 2011
Summary
Organisms survive dehydration by scavenging free radicals with antioxidants, primarily glutathione. This antioxidant system is crucial for preventing cell damage and programmed cell death, enabling desiccation tolerance.
Area of Science:
- Biochemistry
- Cell Biology
- Ecology
Background:
- Water availability is essential for most organisms.
- Some organisms, including plants, fungi, and certain animals, exhibit desiccation tolerance.
- Water removal causes damage, primarily through free radical-induced oxidative stress.
Purpose of the Study:
- To discuss biochemical mechanisms conferring desiccation tolerance.
- To identify key molecules involved in protecting against desiccation damage.
- To explore the role of antioxidants and glutathione in survival and programmed cell death.
Main Methods:
- Literature review and synthesis of existing research on desiccation tolerance.
- Analysis of biochemical pathways and molecular mechanisms.
- Comparison of antioxidant strategies across different life forms.
Main Results:
- Free radicals are a major cause of cell death during desiccation.
- Antioxidants like glutathione, ascorbate, and tocopherols are crucial for scavenging free radicals.
- Glutathione is a universal intracellular antioxidant essential for desiccation survival.
- Secondary phenolic compounds contribute to antioxidant defense in lichens and seeds.
- Failure of antioxidant systems can trigger programmed cell death, leading to aging and death.
Conclusions:
- Desiccation tolerance relies on robust antioxidant machinery to manage free radical damage.
- Glutathione plays a dual role: protecting against oxidative stress and signaling programmed cell death.
- Effective antioxidant defense is a fundamental mechanism underlying the survival of organisms in a desiccated state.
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