FIG. 4.

Carotenoid contents of Synechococcus OS-B′ cells grown at different light irradiances and following a shift in the light conditions. (A) Carotenoid/Chl a ratios (g carotenoid/g Chl a) for P1, zeaxanthin, and β,β-carotene in Synechococcus OS-B′ cultures grown in LL, ML, and HL. Growth light irradiances are indicated in the graph. (B) Kinetics of change of carotenoid/Chl a ratios in cultures grown in LL and then transferred to HL. Note that the time axis is discontinuous. Error bars are given as described in the legend to Fig. 1.