Figure 2. Photosynthetic pigment accumulation under iron-limiting conditions.

Pigment levels were measured in the wild type (open circles) and the pfsR deletion mutant (closed circles) grown under iron-limiting conditions for various lengths of time. Chlorophyll a (A) and total carotenoids (B) were extracted in dimethylfluoride (DMF) and quantified spectroscopically. Phycocyanin content (C) was determined by the loss of phycobiliprotein absorbance in samples after heating. Data (means±SD) are based on three independent experiments.