ACTIVATION OF THE CYCLIC PHOTOPHOSPHORYLATION DURING THE INDUCTION OFTHE CO2-CONCENTRATING MECHANISM IN CHLAMYDOMONAS-REINHARDTII CELLS

Authors
Citation
Ed. Demidov, ACTIVATION OF THE CYCLIC PHOTOPHOSPHORYLATION DURING THE INDUCTION OFTHE CO2-CONCENTRATING MECHANISM IN CHLAMYDOMONAS-REINHARDTII CELLS, Russian journal of plant physiology, 41(2), 1994, pp. 166-171
Citations number
29
Categorie Soggetti
Plant Sciences
ISSN journal
10214437
Volume
41
Issue
2
Year of publication
1994
Pages
166 - 171
Database
ISI
SICI code
1021-4437(1994)41:2<166:AOTCPD>2.0.ZU;2-N
Abstract
Photophosphorylation in Chlamydomonas reinhardtii (mutant cw-92 devoid of cell walls) was studied in order to clarify the involvement of cyc lic photophosphorylation in the mechanism of CO2 concentration. Cells transfer from high (2 - 5%) to low (0.03%) CO2 concentrations, in addi tion to increasing cell affinity for CO2, reversibly inactivated PS II and the V(max). In response to the decrease in CO2 concentration, a 2 - to 3-fold increase in the cyclic photophosphorylation rate was obser ved. A conclusion was drawn that the ATP energy of cyclic phosphorylat ion might sustain the active transport of CO2 against the concentratio n gradient during the induction of the CO2-concentrating mechanism. Th e phenomenon of energy storage surpassing the rate calculated upon O2- gas exchange previously reported for Chlorella cells is also anticipat ed to be a manifestation of energy of the intracellular CO2-Concentrat ing mechanism.