Finger Millet (Eleusine coracana (L.) Gaertn): Nutritional Importance and Nutrient Transporters

Finger millet is a nutri-rich cereal crop of poor people living in the developing countries of Asia and Africa. Finger millet grains contain high amounts of potassium, phosphorus, magnesium, calcium, manganese, copper, zinc, and iron. Its calcium content is 10-fold higher than all other cereals and even three times higher than milk. Finger millet seeds are also rich in cystine, methionine, tryptophan, and total aromatic amino acids as compared to other cereals. Genome sequence of finger millet gives us the opportunity to study the nutrient transporters. No attempt has been made to analyze and improve the nutrient transport in finger millet based on the genome sequence. In this review, we discuss the nutritional importance of finger millet and report the details on key nutrient transporters for the first time. We have performed a genome-wide identification of various mineral nutrient transporters (nitrogen, ammonia, phosphorous, sulfur, potassium, and micronutrients) of finger millet and analyzed their protein sequences with those of various model cereals by various computational tools. Phylogenetic relationship of each nutrient transporter with those of other plants was analyzed and reviewed. The conserved and functional residues of nutrient transporters are analyzed through homology modeling and multiple sequence alignment using transporters with available crystal structures as templates and those from key cereals. This review may provide a foundation for further studies on these nutrient transporters and would help improve the nutrient transport in finger millet and other cereals to conserve food and nutrient security in the developing countries of Asia and Africa.