Beyond red/far‐red sensing: phytochrome perception of the marine light field by microalgae

Phytochromes (PHYs) are a major group of photoreceptors, described as red and far-red light sensors in land plants. Recent genomic and metagenomic explorations have revealed the presence of PHYs also in various eukaryotic microalgae originating from distinct endosymbiotic events. Growing evidence indicates that these PHYs are spectrally and functionally tuned to shorter wavelengths, which are prevalent in the aquatic environments as depth increases. Investigations using emerging phytoplankton mo