Reactive oxygen species (ROS) accumulation
nounPronunciation: /riˈæktɪv ˈɒksɪdʒən ˈspiːʃiz əˌkjuːmjəˈleɪʃən/
The excessive buildup of highly reactive molecules including superoxide (O₂⁻), hydrogen peroxide (H₂O₂), and hydroxyl radicals (•OH) generated during stress conditions as byproducts of cellular respiration. Uncontrolled ROS causes oxidative damage to proteins, lipids, and nucleic acids.
Plain English
Harmful unstable molecules build up in plant cells during stress, damaging cellular structures if not neutralized.
Etymology & History
Usage
"ROS accumulation in drought-stressed maize leaves was accompanied by increased expression of antioxidant enzyme genes."
Style guide notes: Specify which ROS types when possible; ROS is acceptable abbreviation after first mention; avoid 'free radical' as sole descriptor.
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Frequently Asked Questions
How do plants defend against ROS accumulation?
Through enzymatic antioxidants like catalase and SOD, and non-enzymatic antioxidants like ascorbate and glutathione.
What stresses cause ROS accumulation in plants?
Drought, heat, cold, salinity, heavy metals, and UV radiation all trigger excessive ROS production in cells.
Why Test Candidates on This?
Central to understanding cellular damage mechanisms in all abiotic stress responses; frequently assessed in molecular biology contexts.
Required skill level: Mid