Our group has been pioneer in the study of the TOR signaling pathway and autophagy in photosynthetic organisms using the unicellular green alga Chlamydomonas reinhardtii as model system. We have shown that TOR negatively regulates autophagy for the first time in a photosynthetic organism. The main goal of our research is to identify the nutrients and the underlying mechanisms that activate TOR in photosynthetic eukaryotes. To this aim, we have demonstrated that the photosynthetic assimilation of CO 2 activates TOR through the synthesis of a set of central amino acids in carbon metabolism. Our group has also shown that phosphorus, an essential macronutrient, signals to TOR via LST8 in Chlamydomonas.