Figure 5

alr2242 promoter- gfp was upregulated in vegetative cells of the Δ hetR mutant strain. A. Map of the full-length promoter region upstream of alr2242 that was used to drive GFP reporter expression. Bent arrow labeled TSS marks a transcription start site identified by differential RNA-seq [26]. B. The alr2242 full-length promoter fused to gfp in WT cells was not expressed prior to nitrogen deprivation (0 h). At 21 hours after nitrogen deprivation, the alr2242 promoter was expressed at a low level in vegetative cells but was off in heterocysts. However, it was strongly expressed in vegetative cells of the ΔhetR strain in N + conditions (0 h).