Sensing and Signalling in Diatom Responses to Abiotic Cues.

Diatoms are prominent microalgae that proliferate in a wide range of aquaticenvironments. Still, fundamental questions regarding their biology, such as howdiatoms sense and respond to environmental variations, remain largely unanswered.In recent years, advances in the molecular and cell biology of diatomsand the increasing availability of genomic data have made it possible to exploresensing and signalling pathways in these algae. Pivotal studies of photosensoryperception have highlighted the great capacity of diatoms to accurately detectenvironmental variations by sensing differential light signals and adjust theirphysiology accordingly. The characterization of photoreceptors and light dependentprocesses described in this review, such as plastid signalling and dielregulation, is unveiling sensing systems which are unique to these algae,reflecting their complex evolutionary history and adaptation to aquatic life.Here, we also describe putative sensing components involved in the responsesto nutrient, osmotic changes, and fluid motions. Continued elucidation of themolecular systems processing endogenous and environmental cues and theirinteractions with other biotic and abiotic stress signalling pathways is expectedto greatly increase our understanding of the mechanisms controlling the abundance and distribution of the highly diverse diatom communities in marineecosystems.