Fig. 2: Far-Red Light Photoacclimation in the Chroococcidiopsidales.

The synthesis of red-shifted chlorophylls and their incorporation into photosystems can be seen in confocal micrographs (left). In addition to florescence emission from chlorophyll a and phycobilisomes (magenta, 660–700 nm), there is emission from chlorophyll f (yellow, 720–750 nm). Rightmost micrographs mark the overlay of both channels. Excitation, 488 nm. Scale bar, 10 µm. Spectral characteristics can be also observed through a fluorescence emission scan, with the aforementioned channels highlighted (second column from the right). Y-axis: Intensity (a.u.). Composite graph for a minimum of 3 cells. Pigments were extracted and analyzed by HPLC (right). Absorbance traces at 696 nm are shown, indicating the presence of chlorophyll d (16.3 min), f (16.7 min) and a (19.0 min).