Diatom Phytochromes Reveal the Existence of Far-Red-Light-Based Sensing in the Ocean
- 3 March 2016
- journal article
- research article
- Published by Oxford University Press (OUP) in Plant Cell
- Vol. 28 (3), 616-628
- https://doi.org/10.1105/tpc.15.00928
Abstract
The absorption of visible light in aquatic environments has led to the common assumption that aquatic organisms sense and adapt to penetrative blue/green light wavelengths but show little or no response to the more attenuated red/far-red wavelengths. Here, we show that two marine diatom species, Phaeodactylum tricornutum and Thalassiosira pseudonana, possess a bona fide red/far-red light sensing phytochrome (DPH) that uses biliverdin as a chromophore and displays accentuated red-shifted absorbance peaks compared with other characterized plant and algal phytochromes. Exposure to both red and far-red light causes changes in gene expression in P. tricornutum, and the responses to far-red light disappear in DPH knockout cells, demonstrating that P. tricornutum DPH mediates far-red light signaling. The identification of DPH genes in diverse diatom species widely distributed along the water column further emphasizes the ecological significance of far-red light sensing, raising questions about the sources of far-red light. Our analyses indicate that, although far-red wavelengths from sunlight are only detectable at the ocean surface, chlorophyll fluorescence and Raman scattering can generate red/far-red photons in deeper layers. This study opens up novel perspectives on phytochrome-mediated far-red light signaling in the ocean and on the light sensing and adaptive capabilities of marine phototrophs.Keywords
This publication has 65 references indexed in Scilit:
- Tara Oceans studies plankton at planetary scaleScience, 2015
- MAREDAT: towards a world atlas of MARine Ecosystem DATaEarth System Science Data, 2013
- Genome-wide diel growth state transitions in the diatom Thalassiosira pseudonanaProceedings of the National Academy of Sciences, 2013
- Gene Regulation of Carbon Fixation, Storage, and Utilization in the Diatom Phaeodactylum tricornutum Acclimated to Light/Dark CyclesPlant Physiology, 2012
- Bacterial phytochromes: More than meets the lightCritical Reviews in Biochemistry and Molecular Biology, 2011
- Diatom PtCPF1 is a new cryptochrome/photolyase family member with DNA repair and transcription regulation activityEMBO Reports, 2009
- The Phaeodactylum genome reveals the evolutionary history of diatom genomesNature, 2008
- The Genome of the Diatom Thalassiosira Pseudonana : Ecology, Evolution, and MetabolismScience, 2004
- Convection and primary production in winterMarine Ecology Progress Series, 2003
- Penetration of light into soil and its role in the control of seed germinationPlant, Cell & Environment, 1985