Figure 5: Three traces of PSI measurements from oscillations in PSI reduction induced by spike in CO2, which demonstrate varying levels of re-reduction during saturating flashes. Typically, a saturating flash should fully oxidize PSI, but kinetics in electron transport can change this. (a) Extreme re-reduction of PSI can be seen during a saturation flash when PSI is most reduced, 40 s after beginning an elevated CO2 pulse. This demonstrates a high level of PSI-acceptor side limitation. (b) Less re-reduction of PSI during a saturation flash is seen when PSI is less limited by electron acceptors 60 s after beginning a CO2 pulse. (c) After returning to a new steady-state 100 s after beginning an elevated CO2pulse, PSI acceptor-side limitation is much diminished, and PSI re-reduction is minimal.
Figure 6