Photooxidative damage
nounPronunciation: /ˌfoʊtoʊˌɒksɪˈdeɪtɪv ˈdæmɪdʒ/
Cellular injury resulting from excessive light energy and reactive oxygen species (ROS) production that overwhelms antioxidant defense systems, particularly during high-light stress combined with temperature extremes. This damage manifests as chlorophyll degradation, lipid peroxidation, and protein inactivation.
Plain English
Plant cell damage caused by too much light creating harmful reactive oxygen molecules that destroy cellular components.
Etymology & History
Usage
"Alpine plants exposed to intense ultraviolet radiation exhibited severe photooxidative damage unless they possessed elevated carotenoid concentrations."
Style guide notes: Distinguish from photoinhibition; clarify ROS involvement and oxidative stress mechanisms.
Also known as
Contrasted with
Related Terms
Frequently Asked Questions
Why does photooxidative damage increase under combined heat and light stress?
High temperature reduces photosynthetic efficiency and antioxidant enzyme activity, allowing ROS accumulation despite high light conditions.
Which plant tissues are most susceptible to photooxidative damage?
Photosynthetically active leaves, especially thylakoid membranes containing photosystem complexes, experience greatest damage from ROS.
Why Test Candidates on This?
Essential for understanding light stress mechanisms and plant responses to combined environmental stresses.
Required skill level: Mid