Biofortification to Struggle Against Iron Deficiency

Iron is an essential micronutrient for human beings, but it is not readily available. Consequently, iron deficiency is a major threat to the health and development of the human populations in the world with more than 2 billion people suffering from iron-deficiency anemia. To alleviate iron deficiency, dietary modification or diversification, iron supplementation or food fortification, and crops biofortification have been adopted. Crops biofortification, achieved through three approaches: agronomic intervention, plant breeding, and genetic engineering, could provide a sustainable and cost-effective solution for iron deficiency in food. Agronomic intervention is a traditional approach to increase the yield and quality of crops. Some researches indicate that the application of nitrogen fertilizer and intercropping, such as maize/peanut, guava/sorghum or maize and chickpea/wheat, can facilitate iron uptake by crops. Plant breeding could improve the level and bioavailability of minerals in staple crops through their natural genetic variation. The variation in iron concentration of wheat, maize, and rice suggests that selective breeding might increase the iron content of these staple foods. The transgenic approach for iron biofortification focuses on improving iron accumulation and bioavailability, or decreasing anti-nutrient contents in crops. Expressing ferritin, an iron storage protein, has achieved great success in enhancing iron concentration in seeds. Studies have shown that cysteine could enhance iron absorption in human bodies and thus, greater iron availability is expected by increasing the amount of cysteine residues in crop tissues. Reducing antinutrients such as phytic acid can also increase the bioavailability of iron.