A spectroscopic analysis of a high fluorescent mutant of Chlamydomonas reinhardi.
Chloroplast fragments of a high fluorescent mutant of Chlamydomonas reinhardi, hfd 91, were compared against those of Acl(+), a low chlorophyll variant of the wild type. The chloroplast fragments of the mutant which have a high invariant fluorescence yield lacked photochemical activities associated with photosystem II (PSII) but retained normal photosystem I (PSI) activities. The mutant fragments also lacked the low temperature (-196 degrees C) light-induced absorbance changes due to the photoreduction of C-550 and the photooxidation of cytochrome (cyt) b-559 which are PSII-mediated reactions. A fourth-derivative analysis of the absolute spectra of the chloroplast fragments at different stages of reduction (obtained with ferricyanide, ascorbate, and dithionite) showed both the oxidized and reduced forms of C-550 and the reduced forms of cyt c-553, b-559, and b-564 in wild-type fragments. The mutant fragments lacked C-550 and an ascorbate-reducible cyt b-559 but contained cyt c-553, a dithionite-reducible cyt b-559, and cyt b-564.
D001205:Ascorbic Acid / Q000494:pharmacology; D002696:Chlamydomonas / Q000166:cytology / Q000378:metabolism; D000460:Chlorophyta / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism*; D003201:Computers; D003580:Cytochromes / Q000378:metabolism; D004579:Electron Transport; D005295:Ferrocyanides / Q000494:pharmacology; D005453:Fluorescence; D005827:Genetics, Microbial; D009154:Mutation; D010788:Photosynthesis; D013053:Spectrophotometry; D013447:Sulfites / Q000494:pharmacology
D003580:Cytochromes; D005295:Ferrocyanides; D013447:Sulfites; D001205:Ascorbic Acid