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ERIC Number: EJ939423
Record Type: Journal
Publication Date: 2005
Pages: 3
Abstractor: As Provided
Reference Count: 4
ISSN: ISSN-0021-9266
Photoinhibition of Photosystems I and II Using Chlorophyll Fluorescence Measurements
Quiles, Maria Jose
Journal of Biological Education, v39 n3 p136-138 2005
In this study the photoinhibition of photosystems (PS) I and II caused by exposure to high intensity light in oat ("Avena sativa," var Prevision) is measured by the emission of chlorophyll fluorescence in intact leaves adapted to darkness. The maximal quantum yield of PS II was lower in plants grown under high light intensity than in plants grown under low intensity, which indicates that PS II is photoinhibited by such conditions. PS I was more stable than PS II in plants exposed to strong light for a moderate time (five photoperiods) since the oxidised plastoquinone pool size under far-red (FR) light was similar in plants grown under high light intensity to plants grown under low intensity, probably as a result of the cyclic electron flow around PS I being stimulated in response to high light intensity. However, over longer times (10 photoperiods) the PS I was photoinhibited, since the oxidised plastoquinone pool size under FR light increased as a consequence of the decrease in PS I activity caused by high light intensity. This practical is intended for advanced students of plant biochemistry and plant physiology. (Contains 1 figure and 2 tables.)
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Publication Type: Journal Articles; Reports - Research
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A