FIG 4.

Interspecies interactions can alter spatiotemporal bldN expression in S. coelicolor. (A, left) Patch of wild-type S. coelicolor harboring the P_redZ-eGFP and P_bldN-mCherry plasmids grown alone and exhibits development and morphology similar to that of an individual colony. (Middle) When grown near wild-type AA4, S. coelicolor has reduced aerial hypha formation on the side that is closest to AA4 due to depleted iron levels (white arrow). (Right) S. coelicolor, when grown next to the ΔamcG mutant (amychelin-deficient AA4), has restored aerial hypha formation, indicating iron is important for aerial hypha formation. (B) Representative micrograph of S. coelicolor patch harboring P_redZ-egfp and P_bldN-mcherry plasmids when grown alone over 36 h. Similar to the wild type, the fluorescent micrographs of the S. coelicolor patch exhibit redZ preceding bldN expression. (C) S. coelicolor harboring P_redZ-egfp and P_bldN-mcherry plasmids, when grown next to AA4, has reduced aerial hypha formation (white arrow) and reduced P_bldN-mcherry expression at the interaction interface, as shown in the representative fluorescent micrograph at 36 h. The yellow circle depicts the AA4-interacting strain for reference (not shown in the micrograph). (D) When grown next to the AA4 ΔamcG mutant, S. coelicolor P_bldN-mcherry expression is restored, as is aerial hypha formation at the interaction interface (white arrow) at 36 h, as shown in the representative BF/fluorescence micrographs. The yellow circle depicts the ΔamcG AA4 mutant-interacting strain for reference (not shown in the micrograph). (B to D) Scale bar, 1 mm.