Evidence for a linear variation of the miss and single hit S-state probabilities with the flash number, measured by oxygen evolution in Dunaliella tertiolecta.

Oxygen evolution in Dunaliella tertiolecta under flashing light was measured with a bare electrode, at a 10 Hz frquency. The 'sigma coefficients' of the oxygen evolution recurrence law (Thibault (1978) J Theor Biol 73, 271) were determined using groups of nine consecutive points. The S-state transition probabilities were computed from the sigma coefficients and plotted as a function of the flash number of the first of the points used. Low standard deviations over the sigma coefficients resulted from the use of our system (Meunier & Popovic (1988) Rev Sci Instr 59, 486). We observed a linear lowering of the miss probability with time, and a linear rise of the single-hit probability with the same absolute value of the slope. The hypothesis that the slopes were zero was statistically tested and was rejected with a 99.9% confidence interval. Our work demonstrates that, to be accurate, an oxygen evolution model has to take the variations in the properties of S-states into account.