Relative mRNA levels of B739_0103 and B739_0173 in R. anatipestifer CH-1 and its derived strains. R. anatipestifer CH-1, R. anatipestifer CH-1Δfur and R. anatipestifer CH-1ΔfurpLMF03::fur were grown in GCB or GCB supplemented with 100 μM EDDHA at 37 °C in a shaking incubator to the exponential growth phase (OD600 = 1.0–1.5). Total RNA and cDNA of these strains were prepared as described in the “Materials and methods”, and then the transcription of B739_0103 and B739_0173 was measured by qRT-PCR. Relative fold changes are reported in comparison with the parent strain. “c” means the complementary strain R. anatipestifer CH-1ΔfurpLMF03::fur. Statistical significance was determined using two-way ANOVA (****P < 0.0001).