Plant responses to iron nutrition with emphasis on the underutilized crop tef ( Eragrostis tef ): A review

Societal Impact Statement Iron (Fe) deficiency limits the physical health, cognitive development, and economic output of billions of people globally, especially children and productive‐age women. Tef is an underutilized and stress‐resilient crop, which is becoming popular for its grains containing high bioavailable Fe and has the potential to mitigate Fe deficiency. In this review, the mechanisms by which plants take up Fe from the soil and store it in their grains are highlighted, which have implications in biofortification strategies. Promoting tef consumption will enhance nutrition in vulnerable communities, fortify food networks, and promote equitable and sustainable agriculture in the face of climate change. Summary Iron (Fe) deficiency is a common problem worldwide, affecting over a quarter of the world's population. This is largely because of the consumption of predominantly major cereal crops such as rice, corn, and wheat, which are low in Fe. The mechanisms of Fe uptake, transport, and accumulation have been studied in model plants such as Arabidopsis thaliana and some major crops. Contrary, these mechanisms have not been investigated in Fe‐rich underutilized crops such as tef ( Eragrostis tef ). Comparison of Fe concentrations across various food crops reveals that tef contains significantly higher Fe levels than major crops such as rice and wheat. Tef has been a staple crop in Ethiopia and Eritrea for thousands of years. In Ethiopia, it is the most important cereal crop, supporting nearly 80 million people. Tef is grown on about 3 million hectares of land in Ethiopia alone, accounting for 30% of the total cereal acreage and producing nearly 5 million tons of grain. In this review, the mechanisms and strategies for Fe transport and accumulation, as well as for Fe uptake in plants, have been discussed in detail. We performed comparative genomics of Fe‐responsive genes in tef and other model and crop plants and concluded that there is a need to scrutinize Fe transport mechanisms in tef that have the potential to improve Fe content in other crops.