ISSN:
1432-072X
Keywords:
Transient state
;
Light limitation
;
Chlorophyll a
;
Phycobiliproteins
;
Cyanobacteria
;
Photosynthesis
;
Light-shade adaptation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Transitions in growth irradiance level from 92 to 7 μEm-2 s-1 and vice versa caused changes in the pigment contents and photosynthesis of Oscillatoria agardhii. The changes in chlorophyll a and C-phycocyanin contents during the transition from high to low irradiance (H→L) were reflected in photosynthetic parameters. In the L→H transition light utilization efficiencies of the cells changed faster than pigment contents. This appeared to be related to the lowering of light utilization efficiencies of photosynthesis. As a possible explanation it was hypothesized that excess photosynthate production led to feed back inhibition of photosynthesis. Time-scales of changes in the maximal rate of O2 evolution were discussed as changes in the number of reaction centers of photosystem II in relation to photosynthetic electron transport. Parameters that were subject to change during irradiance transitions obeyed first order kinetics, but hysteresis occurred when comparing H→L with L→H transients. Interpretation of first order kinetic analysis was discussed in terms of adaptive response vs changes in growth rate.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00470870
