Queuosine promotes wecB-dependent phage resistance and biofilm formation in marine bacterium Shewanella glacialimarina

Transfer RNA (tRNA) modifications critically fine-tune translational accuracy and efficiency, influencing bacterial adaptation to environmental challenges. Among these, the queuosine (Q) modification has recently emerged as a regulator of biofilm formation, yet its role during phage infection remains unknown. Here, we investigate how Q modification links host translational control to phage infection. We show that phage infection activates the Q biosynthetic pathway, leading to elevated Q levels and enhanced translation of NAT-biased genes. This shift drives two interconnected outcomes, namely increased biofilm formation and enhanced mutagenesis mediated by translesion synthesis polymerases. We further identify conserved, slippage-prone regions within surface-related genes that act as hotspots for adaptive variation. Together, our findings uncover a novel mechanistic link between tRNA modification and phage-driven bacterial diversification.