Genome-Wide Analysis of Iron and Zinc Transporter Genes Identifies Putative Candidates for Sorghum Biofortification

Sorghum bicolor (L.) Moench is a valuable cereal crop for tackling micronutrient malnutrition globally through biofortification of essential nutrients, iron (Fe) and zinc (Zn). Sorghum seeds exhibit significant variability in Fe and Zn content, yet only two biofortified varieties have been released so far. In this study, a comprehensive in silico identification, characterization, and expression analysis of Fe and Zn transporters was conducted to shortlist putative candidates for sorghum seed biofortification. A total of 61 transporters belonging to YSL, ZIP, HMA, NRAMP, NAS, FER, and VIT gene families were shortlisted. Their gene models, unique motifs, chromosomal locations, phylogenetic relationships, protein–protein interactions, and cis-elements were determined. Expression profiling of developing S. bicolor M35-1 seeds, and other tissues including leaf, stem, root, panicle, and mature seeds revealed putative candidates regulating Fe and Zn accumulation in seeds. These candidates will leverage future breeding and genome editing efforts for sorghum seed biofortification.