Figure 2.

Daily variations of the ratios of the two major carotenoids (zeaxanthin and carotene) to chlorophyll a for picocyanobacterial cells acclimated to a modulated 12/12 h L/D cycle of VL with or without UV radiations. (A,C) Synechococcus sp. WH7803. (B,D) Prochlorococcus marinus PCC 9511. White and black bars above graphs indicate light and dark periods, also delineated by vertical bars and areas filled in yellow. Error bars indicate mean deviation for two biological replicates. Abbreviations as in Figure 1.