Fig. 3.

O₂ production and consumption rates per PSII of Synechocystis sp. PCC 6803 wildtype (a, b) and the PAL mutant (c, d). Cells were acclimated to orange-red (a, c) or blue (b, d) light and subsequently exposed to increasing intensities of the same light color. The data show averages of gross photosynthetic O₂ production (diamonds), net O₂ production (circles), and O₂ consumption (triangles), measured in duplicate samples using membrane-inlet mass spectrometry (MIMS). Lines represent P–I curves fitted to the gross O₂ production using the hyperbolic tangent function; parameter estimates are given in Table 2