Autophagy is an adaptive response by which eukaryotic cells cope with stress to maintain cellular homeostasis. Our studies using the single-cell microalga Chlamydomonas reinhardtii have shown that this catabolic process is negatively controlled by the TOR signaling pathways and is upregulated upon a wide range of stress conditions including chloroplast damage, metal toxicity or oxidative stress. The main goal of our research is to unravel the molecular mechanisms by which redox signals modulate autophagy. To this aim, using in vitro and in vivo approaches, we are analyzing the regulation of the ATG8 lipidation system.