Growth rates of <i>Synechocystis</i> sp. PCC 6803 substrains GT-L (white circles), GT-B (red triangles) and PCC-B (blue squares) under increasing red, blue and white light.

<p>A, B–Red light was set to intensities of 25–660 μmol(photons) m<sup>-2</sup> s<sup>-1</sup> and it was supplemented with 25 μmol(photons) m<sup>-2</sup> s<sup>-1</sup> of blue light. The experiments were performed at 32°C (A) and 35°C (B). C–Red light of 220 μmol(photons) m<sup>-2</sup> s<sup>-1</sup> was supplemented with 25–220 μmol(photons) m<sup>-2</sup> s<sup>-1</sup> of blue light under 32°C. D–Red light of 220–8 μmol(photons) m<sup>-2</sup> s<sup>-1</sup> was supplemented with white light of 0–790 μmol(photons) m<sup>-2</sup> s<sup>-1</sup> (at 32°C) in order to keep the red photons (as a combination of red light and part of the white spectra) constant at 220 μmol(photons) m<sup>-2</sup> s<sup>-1</sup> (according to [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0189130#pone.0189130.ref019" target="_blank">19</a>]). All experiments were carried out in a quasi-continuous regime as described in the main text under growth saturating CO<sub>2</sub> concentration of 5 000 ppm. Each point represents average of at least four independent experiments, error bars represent standard errors. The dashed lines in panels A and B represent fitting of the data points by the function derived by Platt et al. (1980) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0189130#pone.0189130.ref051" target="_blank">51</a>]. The dashed lines in panels C and D represent linear fitting of the data points by the least squares method. Legend in panel D represents particular combinations of white light (W) and red light (R) in units of μmol(photons) m<sup>-2</sup> s<sup>-1</sup>.g.</p>