Identification of a dual orange/far-red and blue light photoreceptor from an oceanic green picoplankton

Photoreceptors are conserved in green algae to land plants and regulate various developmental stages. In the ocean, blue light penetrates deeper than red light, and blue-light sensing is key to adapting to marine environments. Here, a search for blue-light photoreceptors in the marine metagenome uncover a chimeric gene composed of a phytochrome and a cryptochrome (Dualchrome1, DUC1) in a prasinophyte, Pycnococcus provasolii. DUC1 detects light within the orange/far-red and blue spectra, and acts as a dual photoreceptor. Analyses of its genome reveal the possible mechanisms of light adaptation. Genes for the light-harvesting complex (LHC) are duplicated and transcriptionally regulated under monochromatic orange/blue light, suggesting P. provasolii has acquired environmental adaptability to a wide range of light spectra and intensities. Blue light penetrates deeper than red light in ocean, thus blue light sensing is critical for adaptation to marine environments. Here, the authors report the genome of Pyconococcus provasolii and identify a chimeric dual orange/far-red and blue light receptor composed of a phytochrome and a cryptochrome by analyzing the marine metagenomes.

Automated summary

Photoreceptors are crucial for various developmental stages from green algae to land plants, and blue light sensing is essential for adapting to marine environments. The discovery of a chimeric dual orange/far-red and blue light receptor in Pycnococcus provasolii sheds light on the mechanisms of light adaptation in marine organisms.