Antioxidant defense system
nounPronunciation: /ˌæntiˈɒksɪdənt dɪˈfens ˈsɪstəm/
The coordinated network of enzymatic and non-enzymatic antioxidants including superoxide dismutase (SOD), catalase (CAT), peroxidases, and ascorbate-glutathione cycle components that neutralize reactive oxygen species generated during abiotic stress. A robust defense system is critical for maintaining cellular redox homeostasis.
Plain English
The collection of enzymes and molecules plants use to neutralize harmful reactive oxygen species produced during stress.
Etymology & History
Usage
"Enhanced antioxidant defense system activity was associated with superior cold tolerance in the transgenic potato lines."
Style guide notes: Specify enzymatic versus non-enzymatic components when discussing antioxidant defense mechanisms in detail.
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Frequently Asked Questions
What are the main enzymes in plant antioxidant defense?
Superoxide dismutase (SOD), catalase (CAT), and peroxidases are primary enzymes, supported by ascorbate-glutathione cycle components.
How does antioxidant capacity relate to stress tolerance?
Stronger antioxidant systems better neutralize stress-induced ROS, protecting proteins, lipids, and DNA from oxidative damage.
Why Test Candidates on This?
Commonly assessed in advanced plant physiology, biochemistry, and stress biology examinations.
Required skill level: Senior