Iron biofortification in wheat: Past, present, and future

Iron (Fe) deficiency is a pressing global health concern, particularly affecting vulnerable groups like women and children in resource-limited areas. Addressing this challenge requires innovative solutions, and biofortified crops, like Fe-enriched wheat, can offer a sustainable solution to improve nutrition in cereal-based diets. While conventional breeding methods have yielded competitive Fe-biofortified wheat varieties across various nations, the imminent challenges in securing food and nutritional security for the future necessitate a delicate balance: maintaining genetic progress in grain yield while concurrently elevating grain Fe content. Despite substantial strides in elucidating the intricacies of Fe homeostasis, there remains a substantial knowledge gap, especially in the context of wheat and similar crop species. It is paramount to gain a comprehensive understanding of the hurdles impeding Fe enrichment in plant tissues and delve into the diverse mechanisms governing Fe uptake, translocation, transport, and storage within wheat. To surmount these challenges, researchers have explored a multitude of strategies, including mutagenesis, QTL mapping, meta-QTL analysis, GWAS, transgenesis, and genome editing. Furthermore, harnessing the potential of microorganisms, particularly engineered endophytes coupled with plant genes associated with Fe accumulation, emerges as a promising and pragmatic tool for augmenting Fe biofortification in wheat. This comprehensive review underscores the significant advancements made in unravelling the genetic and genomic aspects of Fe accumulation in wheat, while also delineating the future research directions in this field. By synergistically deploying these multifaceted approaches, scientists hold the potential to develop wheat varieties characterized by enhanced grain Fe content, improved bioavailability, and reduced anti-nutritional factors. Such innovations can play a pivotal role in advancing nutrition and health outcomes for populations reliant on wheat-based diets, particularly in resource-scarce regions.