Bacteria use P-body condensates to attenuate host translation during infection.

Abstract

Pathogens use sophisticated strategies to modulate host protein homeostasis by targeting proteolytic pathways, but their impact on protein synthesis remains elusive. We report that pathogenic bacteria <i>Pseudomonas syringae</i> (<i>Pst</i>) targets ribonucleoprotein condensates, known as processing bodies (P-bodies), to attenuate host translation through two effectors with liquid-like properties. We uncovered a previously unknown link that <i>Pst</i>-mediated repression of the endoplasmic reticulum stress response is required for P-body assembly. Furthermore, we identify a functional link between P-bodies and autophagy, demonstrating that autophagic clearance of P-bodies is crucial for maintaining the balance between translationally active and inactive messenger RNAs. Together, our findings provide insights on how host translation is attenuated by bacteria to dampen plant immunity and uncover unknown connections between ER stress responses and autophagy with P-body dynamics.