About the Cover
COVER: Photosynthetic light harvesting in cyanobacteria takes place in phycobilisomes, which contain light-absorbing phycobiliproteins. In Fremyella diplosiphon, the process of complementary chromatic adaptation regulates the biosynthesis of phycobiliproteins, resulting in the accumulation of red-colored phycoerythrin when cells are grown under green light, and blue-colored phycocyanin under red light. This maximizes photosynthetic efficiency by spectrally tuning the absorption characteristics of the phycobilisomes to the predominant wavelength of ambient light. Alvey et al. (pages 2448-2463) report the characterization of the pebAB operon, which encodes the enzymes that catalyze the reduction of biliverdin to phycoerythrobilin, the phycoerythrin chromophore. The image shows wild-type (red) surrounded by pebA mutant (green) cells of Fremyella grown under green light; the mutant appears green because it is unable to synthesize phycoerythrin. Image courtesy of Roger Hangarter, Richard Alvey, and David Kehoe.
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Copyright © 2007 by the American Society of Plant Biologists
