FIG 11.

Siderophore production and uptake are required for full virulence. Ten-day-old sweet corn seedlings were inoculated with either a WT DC283, ΔiucA, or ΔiucA/iucA⁺ strain or 1× PBS buffer (A) or a WT DC283, ΔiutA, or ΔiutA/iutA⁺ strain or 1× PBS buffer (B). Plants were observed for symptom development daily, and disease severity was assessed based on an arbitrary rating system between 0 and 4. The graph represents the mean of three biological replicates with five technical replicates each (a total 15 plants per strain). Experiments were repeated at least three times with similar results. Error bars indicate the standard errors of the mean.