FIGURE 5.
Oxygen evolution and respiration rates for WT, Comp, ΔpsaAB, and Δvipp1, based on equal cell numbers (based on OD730 nm) (A) or equal Chl a (B). The vipp1 mutant strain as well as the psaAB mutant strain had much higher oxygen evolution rates than the WT strain when rates were compared on the basis of Chl but much lower oxygen evolution rates when rates were compared on the basis of equal cell numbers. Note that these values were derived from the initial rates of oxygen evolution for the vipp1 and the psaAB mutant strains, because oxygen evolution rates rapidly declined for these two strains that had no PS I activity to drive the reoxidation of the plastoquinone pool. The data shown are averages values for three biological replicates, and the error bars show the standard deviation.