title: Fluorescence induction in intact spinach chloroplasts.
abstract: Under conditions in which the Photosystem II quencher is rapidly reduced upon illumination, either after a preillumination or following treatment with dithionite, the fluorescence-induction curve of intact spinich chloroplasts (class I type) displays a pronounced dip. This dip is probably identical with that observed after prolonged anaerobic incubation of whole algal cells ("I-D dip"). It is inhibited by 3(3,4-dichlorophenyl)-1,1-dimethylurea and occurs in the presence of dithionite, sufficient to reduce the plastoquinone pool. It is influenced by far red light, methylviologen, anaerobiosis and uncouplers in a manner consistent with the interpretation that it represents a photochemical quenching of fluorescence by an electron transport component situated between the Photosystem II quencher and plastoquinone. Glutaraldehyde inhibition may indicate that protein structural changes are involved.
mesh_terms: D000693:Anaerobiosis; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism*; D003624:Darkness; D004227:Dithionite / Q000494:pharmacology; D004237:Diuron / Q000494:pharmacology; D004579:Electron Transport; D005976:Glutaral / Q000494:pharmacology; D007700:Kinetics; D008027:Light; D010269:Paraquat; D010785:Photophosphorylation / Q000187:drug effects; D010944:Plants; D011809:Quinones / Q000494:pharmacology; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D011809:Quinones; D014475:Uncoupling Agents; D004227:Dithionite; D004237:Diuron; D010269:Paraquat; D005976:Glutaral