This work is a comprehensive perspective on INS (inositol and inositol phosphates) and RFO (Raffinose Family Oligosaccharides) pathways in soybean. Besides genomic analysis, NGS-based transcriptomic methods (HT-SuperSAGE and RNA-Seq) were applied to contrast (tolerant and sensitive) soybean accessions under root dehydration. INS and RFO genes formed large gene families distributed over all twenty soybean chromosomes, and being broadly conserved within the legume clade. In addition, phosphatidylinositol-specific phospholipase C loci, not predicted in previous reports, were identified in the soybean genome. In reference to INS and RFO gene promoter regions, bona fide candidate cis-regulatory elements associated with eight (BBR-BPC, Dof-type, MYB-related, AP2-ERF, MADS-box, WRKY62, SRM1, and Squamosa) different transcription factors were found. Such molecules participate in various processes of plant physiology (e.g., plant defense) suggesting the studied pathways (or specific enzymes) could also participate in these processes in soybean plants. Regarding the transcriptomic assays, both approaches applied had satisfactory results. The transcriptional orchestration of the genes encoding phosphatidylinositol-4-phosphate 5-kinase 6 and galactinol synthase (both induced), besides phosphatidylinositol synthase, myo-inositol monophosphatase and stachyose synthase (all constitutive) enzymes, which modulated similarly in the studied accessions, could represent a general transcriptional signature of both active pathways in soybean plants under root dehydration. The difference observed between the contrasting accessions was associated with the validated transcriptional orchestration (induced, in the tolerant accession; constitutive, in the sensitive accession) of the 1-phosphatidylinositol-3-phosphate 5-kinase enzyme. The results add information to these poorly studied pathways and provide a valuable resource of soybean genes/transcripts that will benefit other studies in this field.