Study of the interdependence of photoprotection mechanisms in model microalgae

While light is essential for the fixation of carbon dioxide by photosynthetic organisms, too intense light levels can be harmful. The oxidative stress caused by the absorption of an excess of photons can lead to the damage of the macromolecules that compose the photosynthetic apparatus, thus causing a decrease in photosynthetic yield. Among the strategies developed by photosynthetic organisms to protect themselves from high light, the ability to move away from it (photophobia) and the thermal dissipation at the level of the light-collecting antennae are the two main strategies described independently in the literature. The purpose of this project is to investigate the articulation between these two photoprotection strategies in two model species of unicellular and motile microalgae : Chlamydomonas reinhardtii (a green alga for which a large collection of mutants exists) and Euglena gracilis (a photosynthetic eukaryotic microalga of great biotechnological interest). In addition, the impact of environmental factors such as light intensity, temperature, medium composition and CO2 concentration will be studied to assess their effect on the dynamic.