Photooxidative stress
nounPronunciation: /ˌfoʊtoʊˌɒksɪˈdeɪtɪv strɛs/
Cellular damage resulting from excessive light energy that generates reactive oxygen species through photosynthetic electron transport chain reactions. This occurs when light absorption exceeds photochemical capacity, leading to lipid peroxidation, protein degradation, and nucleic acid damage.
Plain English
Excess light creates harmful oxygen molecules that damage plant cells and proteins.
Etymology & History
Usage
"Alpine plants experience photooxidative stress due to high UV radiation and intense sunlight at elevation."
Style guide notes: Distinguish photooxidative stress from photoinhibition; the former emphasizes ROS-mediated damage while latter emphasizes photosynthetic capacity loss.
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Related Terms
Frequently Asked Questions
When does photooxidative stress become a concern?
It occurs when light intensity exceeds the plant's photochemical capacity and detoxification mechanisms.
Which environments trigger photooxidative stress?
High-altitude regions, deserts, and high-latitude areas with intense, prolonged sunlight exposure.
Why Test Candidates on This?
Photooxidative stress evaluation is essential for assessing plant adaptation to high-light and high-altitude environments.
Required skill level: Mid