Unveiling molecular mechanisms of iron and zinc dynamics in rice

Iron (Fe) and zinc (Zn) are essential micronutrients critical for human health, yet their deficiencies are widespread, particularly in rice-dependent populations. Rice, a staple food for over half the global population, lacks sufficient bioavailable Fe and Zn in its grains, contributing to global malnutrition. This review delves into the molecular mechanisms governing Fe and Zn transport in rice, focusing on gene families such as IRT, YSL, ZIP, and HMA, which regulate uptake, translocation, and storage. These transporters exhibit intricate interactions and crosstalk, influenced by environmental factors and shared pathways, underscoring the complexity of Fe-Zn homeostasis. Biofortification, through genetic engineering and conventional breeding, emerges as a promising solution to address Fe and Zn deficiencies. Genetic strategies include overexpression of ferritin and nicotianamine synthase genes, alongside manipulation of metal transporter genes, to enhance micronutrient accumulation in rice grains. The advanced breeding approaches including marker-assisted selection and quantitative trait loci (QTL) mapping, complement genetic engineering, offering non-transgenic alternatives for micronutrient enhancement. The common challenges such as regulatory barriers, public perception, and trait stability under diverse conditions necessitate interdisciplinary collaboration and technological advancements.