Toxic effects of copper on photosystem II of spinach chloroplasts
- National Tsing Hua Univ., Taiwan (China)
The room temperature fluorescence induction of chloroplasts was utilized as a probe to locate the site of inhibition on PSII by copper. It was found that, while the initial fluorescence yield was hardly affected, the variable fluorescence yield was lowered without significant change in its kinetics. Addition of DCMU, or abolishing oxygen evolution capability by Tris treatment, did not alter this basic inhibition pattern. Copper was also found to lower the fluorescence yield of chloroplasts treated with linolenic acid which inhibited the secondary electron transport on both oxidizing and reducing sides of PSII. The data indicate that copper adversely affects the primary change separation at the PSII reaction center. We suggest that the inhibition is due to creation of a lesion close to the reaction center, leading to increased dissipation of incoming excitation energy to heat.
- OSTI ID:
- 7189348
- Journal Information:
- Plant Physiology; (USA), Vol. 87:1; ISSN 0032-0889
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COPPER
TOXICITY
PHOTOSYNTHETIC REACTION CENTERS
INJURIES
CHARGE EXCHANGE
CHLOROPLASTS
FLUORESCENCE
INHIBITION
SPINACH
CELL CONSTITUENTS
ELEMENTS
FOOD
LUMINESCENCE
MAGNOLIOPHYTA
MAGNOLIOPSIDA
METALS
PLANTS
TRANSITION ELEMENTS
VEGETABLES
560300* - Chemicals Metabolism & Toxicology