ATG8 delipidation is dispensable for plant autophagy

Autophagy is a catabolic pathway conserved across eukaryotes. It plays a vital role in diverse stress responses by dismantling and recycling unnecessary or dysfunctional cellular parts and is orchestrated by the a u t opha g y related ATG proteins conserved among all eukaryotes[1][1],[2][2]. An astounding conservation of autophagic machinery across eukaryotes highlights the fundamental role it plays in the cell’s homeostasis. In this study we discovered that ATG4-dependent delipidation of ATG8, previously considered as critical step in autophagy mechanism of all eukaryotes, is dispensable in Arabidopsis thaliana . Moreover, using ATG4-deficient background as a model system we uncovered specific function of two Arabidopsis ATG8 orthologs in autophagosome formation. Finally, we demonstrated that ATG8 delipidation is critical for autophagy in evolutionary distant from Arabidopsis species, unicellular green algae Chlamydomonas reinhardtii . These findings provide a new insight on plant-specific aspect of autophagy, highlight important differences between higher and lower plants and she new light on the reasons behind ATG8 gene family expansion. ### Competing Interest Statement The authors have declared no competing interest. [1]: #ref-1 [2]: #ref-2