Advancing Nutritional Quality through Genomic Approaches for Biofortification in Cereal Crops: A Review

Abstract

Hidden hunger, characterized by micronutrient deficiencies, remains a pervasive challenge in marginalized regions worldwide, where the main source of sustenance is cereal crops. This review study examines how improving the nutritional value of cereal crops through genetic "biofortification" could help fight hidden hunger. It focuses on the biochemical and genetic underpinnings of zinc, iron, and critical amino acid accumulation. While conventional breeding efforts have made significant contributions, the complex genetic nature of mineral content in grains presents challenges. In response, molecular techniques such as CRISPR/Cas genome editing offer promising solutions. The paper underscores the widespread prevalence of iron and zinc deficiencies, affecting over a large population. Children under five and pregnant and lactating women in developing countries are particularly vulnerable. Biofortification, defined as the breeding of staple food crops with elevated micronutrient levels, emerges as a cost-effective and sustainable strategy to improve health in resource-poor households. It discusses the transfer of genes and quantitative trait loci (QTLs) from wild and related species to cultivated wheat, emphasizing the need for marker-assisted selection and genomic selection to accelerate breeding progress. The emergence of CRISPR/Cas genome editing techniques in recent decades has revolutionized the field of plant breeding. The paper highlights the successful application of CRISPR/Cas9 in numerous cereal crops such as rice, wheat, maize and barley, to improve crop yields and nutritional content. It also explores the potential for precise base editing and gene expression modifications. However, challenges such as transformation efficiency, specific promoters, and ethical and regulatory concerns are also mentioned and discussed. In conclusion, genetic biofortification through CRISPR/Cas-mediated genome editing presents a promising avenue for alleviating hidden hunger in cereal-dependent regions.