Skip to main content
. 2014 Dec 24;167(2):472–480. doi: 10.1104/pp.114.249987

Figure 4.

Figure 4.

Model of the responses of photosynthesis, FLV activity, electron transport rate (ETR), and oxidation state of the PQ pool to the shift from CO2-saturated to CO2-limited photosynthesis in Synechocystis sp. PCC 6803. This model presents an interpretation of the processes occurring in the experiment shown in Figure 1A. A, CO2 depletion by photosynthesis. Medium [CO2] decreases due to photosynthetic consumption following the start of illumination. B, Suppression of photosynthesis by photosynthesis-induced CO2 depletion. Photosynthetic CO2 consumption cannot be balanced by the diffusion of atmospheric CO2 into the medium. C, Activities of FLV proteins. FLV1 and FLV3 function under CO2-saturated and CO2-limited conditions, while FLV2 and FLV4 become functional as mediators of AEF only under CO2-limited conditions. D, Total ETR under CO2-saturated photosynthesis is driven mainly by photosynthesis. A similar rate is maintained under CO2 limitation by an oxygen-dependent AEF. E, Changes in the redox state of the PQ pool. Under CO2-limited photosynthesis, the oxidized state is preserved by the FLV2/4-mediated, oxygen-dependent AEF.