Project description:This study provides comparative RNA-seq datasets for four freshwater bacterial isolates, Pseudomonas sp. FBCC-B13192, Herbaspirillum sp. FBCC-B12834, Pantoea sp. FBCC-B5559, and Micrococcus sp. FBCC-B5738, cultured under iron-replete (+100 uM FeCl3) and iron-limited (no FeCl3) conditions. Iron availability is a key factor influencing bacterial fitness, and iron limitation is known to activate siderophore biosynthesis, iron transport, and homeostasis pathways. A total of eight libraries generated in 2024 and 2025 were analyzed, comprising 349.9 million processed reads. Reference-guided mapping rates varied among strains, with higher mapping efficiency observed in Pseudomonas, Herbaspirillum, and Pantoea, while Micrococcus showed comparatively lower mapping rates under both conditions. Differential expression analysis revealed strain-specific responses to iron limitation. Genes related to pyoverdine and ferrichrome uptake were enriched in Pseudomonas and Herbaspirillum, enterobactin-associated pathways were prominent in Pantoea, and genes associated with siderophore production, heme utilization, and Fe-S cluster assembly were identified in Micrococcus. Raw sequencing data are available in the NCBI Sequence Read Archive under BioProject PRJNA1456794, and processed data are deposited in a public repository. These datasets provide a valuable resource for understanding bacterial adaptation to iron availability and for comparative transcriptomic analyses.