Making sugar through photosynthesis or consuming it through respiration? These two seemingly opposite metabolic pathways run in parallel in photosynthetic organisms. Although they may occur simultaneously in plant chloroplasts, their interactions remain largely unknown. 

The team led by Richard Dorrell (LCQB) and his colleagues have demonstrated that direct glycolysis of sugar in the chloroplast is common in diatoms, algae that are essential for maintaining marine ecosystems.

Using two techniques - the environmental study of this pathway with the Tara Oceans consortium, and its experimental disruption in the model diatom Phaeodactylum - the authors discover that chloroplast glycolysis enables efficient management of the carbon fixed by photosynthesis. Surprisingly, this pathway is essential at high latitudes, where diatoms are the first link in the marine food chain.