Assistant Professor UNC Greensboro Greensboro, North Carolina
Iron (Fe) availability is extremely limited in most soils, which not only restricts plant growth but also limit Fe accumulation in edible plant tissues. Plants have developed sophisticated mechanisms to cope with limited Fe conditions. The physiological and molecular mechanisms regulating Fe acquisition and accumulation have been characterized in the model plant Arabidopsis thaliana and a few major cereals which are generally poor in Fe content. By contrast, Fe acquisition and storage mechanisms in underutilized “orphan” crops which are rich in bioavailable Fe, for example, tef (Eragrostis tef) remained unknown. Tef is the most important crop in the Horn of Africa and is becoming popular in the western world for its healthy and nutritious grains, and forage quality of its straw. In this study, we exposed tef seedlings to hydroponic condition containing 0 or 6.4 mM Fe and measured plant growth parameters and tissue mineral composition root. Fe deficiency significantly inhibited root and shoot growth and total dry mass and modulated mineral composition in shoots and roots. Moreover, Fe deficient roots exhibited higher ferric reductase activity when cultured in agar media containing a the pH indicator. Furthermore, root and shoot transcriptome analysis in Fe deficient and control plants revealed deferential expression of genes implicated in both Strategy I and Strategy II Fe acquisition mechanisms including transporters, transcription factors and biosynthetic enzymes, suggesting that tef may employ combined strategy for Fe acquisition. Physiological and molecular studies are ongoing to scrutinize the mechanisms of Fe acquisition and storage in tef. This study will serve a foundation for elucidating Fe acquisition mechanisms in closely related orphan crops.