FIG 7.

Synechocystis sp. wild-type and ΔcphA mutant cells starved of nitrogen for 9 days and resuscitated under continuous light in liquid medium supplying fluctuating nitrogen concentrations. Values are the means of three biological replicates. Chlorotic cultures were adjusted to an OD₇₅₀ of 0.5. Resuscitation was induced by adding 10 mM nitrate. After 4 h of nitrogen availability, the cells were washed and resuspended in nitrogen-free BG-11 medium. This routine was repeated over 4 days. The progress of regreening was documented by measuring the absorbance of phycobiliproteins at 630 nm (A) and chlorophyll a/b at 680 nm (B). (C) Growth curve of the two strains.