FIG. 3.

Determination of cAMP levels (pmol cAMP mg chlorophyll a⁻¹) for the N. punctiforme wild type (WT) and mutants C1068, C3212, and H1. Strains were grown to mid-exponential phase in nitrogen-replete medium. After the first sample was collected (time zero), the cells were immediately transferred to dark conditions (indicated by the arrow), and subsequent samples were collected after 1, 5, and 10 min. Four samples were analyzed for each strain, and the error bars indicate the standard errors of the means.