TY - JOUR T1 - A bacterial GW-effector directly targets Arabidopsis Argonaute 1 to suppress PAMP-triggered immunity and cause disease JF - bioRxiv DO - 10.1101/215590 SP - 215590 AU - Odon Thiébeauld AU - Magali Charvin AU - Meenu Singla Rastogi AU - Fan Yang AU - Dominique Pontier AU - Cécile Pouzet AU - Laure Bapaume AU - Delase Amesefe AU - Guangyong Li AU - Laurent Deslandes AU - Thierry Lagrange AU - James R. Alfano AU - Lionel Navarro Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/01/13/215590.abstract N2 - Pseudomonas syringae (P. syringae) type-III effectors were previously found to suppress the Arabidopsis microRNA (miRNA) pathway through unknown mechanisms. Here, we first show that the P. syringae HopT1-1 effector promotes pathogenicity by suppressing the Arabidopsis Argonaute 1 (AGO1)-dependent miRNA pathway. We further demonstrate that HopT1-1 physically interacts with Arabidopsis AGO1 through conserved glycine/tryptophan (GW) motifs. Importantly, this AGO-binding platform was found to be essential for the ability of HopT1-1 to suppress both miRNA activity and PAMP-Triggered Immunity (PTI). These results therefore indicate that the RNA silencing suppression activity of HopT1-1 is intimately coupled to its virulence function. Overall, these findings provide the first evidence that a bacterial effector has evolved to directly target an AGO protein to suppress PTI and cause disease.Competing Interest StatementThe authors have declared no competing interest. ER -