Figure 5. Reduced IIS and oxidative preconditioning require SKN-1 for enhanced pathogen resistance.

(A) daf-2(e1370) mutant nematodes exhibited increased resistance to P. aeruginosa, compared to that of wild-type N2 worms (p<0.0001). skn-1(RNAi) treatment of daf-2(e1370) animals increased the susceptibility to P. aeruginosa infection (p<0.0001). Killing assays were performed with at least 90 young 1-day old adult animals in each condition. (B) H₂O₂ pretreatment increased survival on PA14 in a concentration-dependent manner. Survival curves of N2 wild-type worms treated with various concentrations of H₂O₂ in liquid NGM: 1 mM (p = 0.425), 1.5 mM (p<0.0001) and 2 mM (p<0.0001) 12 h prior to the killing assay are shown. Killing assay was performed with 90 3-day old adult animals in each condition. (C) Oxidative preconditioning-induced pathogen resistance was impaired in the absence of SKN-1 or DAF-16. Increase in survival was less pronounced in either skn-1(zu135) (p = 0.0156) or daf-16(mu86) mutant (p = 0.0304), than in wild-type animals (p<0.0001). Survival curves of the same genetic background were compared in the absence and presence of H₂O₂. Data were combined from at least two experiments with 89 animals in average for each group. EV: empty vector RNAi.