An oomycete effector impairs autophagy in evolutionary distant organisms and favors host infection

An arsenal of effector proteins from plant pathogenic species manipulates their host from inside the cells. produces the effector AVH195 during an initial, biotrophic phase of infection. The protein transiently impairs plant immune-associated hypersensitive cell death in . ATG8 Interaction Motifs in the protein indicate that the effector targets the autophagic core machinery. We selected a photosynthetic microalga with a single copy gene as an alternative model to dissect AVH195-induced autophagic perturbation. AVH195 slows down autophagic flux in thus promoting the accumulation of cargo-rich vesicles. In yeast, membrane-associated AVH195 interacts with ATG8 from Chlamydomonas and with different ATG8 isoforms from . The overexpression of in Arabidopsis promotes growth of both infecting and , an obligate biotroph. To our knowledge, this report provides first evidence that an oomycete effector non-selectively targets ATG8 in different organisms from the green lineage to slow down autophagic flux for infection.