Fig. 5: PA14 nitrogen assimilation impacts bacterial growth and C. elegans pathogenesis.

a Survival of worms infected by PA14 WT and PA14 nirB_Tn (left) or P11mut1 (right). Worms were counted every 10 hours and were declared dead if they were unresponsive to mechanical agitation. Glutamine supplementation (10 mM) decreased worm survival (%) infected by PA14 nirB_Tn (left) or P11mut1 (right) to survival (%) by PA14 WT infections. P value calculated using a Mantel-Cox test compared to PA14 WT (P = < 0.0001). b PA14 CFU’s quantified from worm guts 30 h and 50 h post infection. At 30 h, bacterial load does not differ between strains. At 50 h, PA14 nirB_Tn (left) or P11mut1 (right) is ~2× less abundant than PA14 WT and is rescued by glutamine supplementation (10 mM). P = 0.0007 (left) and P = 0.0002 (right). Bar graph error bars denote SD, center denotes mean, and each dot represents a technical replicate (5 total). One-Way ANOVA analysis was performed compared to WT. Dunett’s multiple comparison test using WT PA14 as control. *p ≤ 0.05. (Prism 9). c RNA sequencing results from PA14 ∆P11 or d PA14 nirB_Tn relative to WT PA14. 3 Biological replicates used per strain. (c, d: left) Volcano plots were generated from all identified genes in the RNA sequencing results. X axis denotes Log₂(Fold Change). Y axis denotes −Log₁₀(P adjusted) with horizontal dotted line denoting Padj = 0.05. Significantly differentially expressed gene in PA14 nirB_Tn were identified based on Log₂(Fold Change) values ≥ 2 or ≤−2 with P adjusted values ≤ 0.05. P values calculated using two-sided quasi-likelihood F test. (c, right) Gene Ontology enrichment analysis was performed to identify differentially expressed gene functional groups. For exact sample size (n), all biological replicates, p values, and full list of quantified genes from RNA sequencing results see source data file.