Unravelling phototaxis-photosynthesis connections in a model microalga.

[Cod. ORPG-6599 PHOTO2]

In plants and algae, light is the substrate for photosynthesis but also a biological signal triggering developmental processes and physiological responses. Key responses have evolved in particular with the primary aim of regulating light exposure and preventing potentially lethal photodamage, particularly critical for photosynthetic organisms. Motile microalgae can regulate light exposure either through biochemical photoprotection or by actively swimming towards/away from the light (phototaxis). How these two regulatory processes interact is not understood. We propose an innovative combination of experiments and theory to address this question and unravel the principles and mechanisms linking phototaxis, photosynthesis and photoprotection.