Transcriptomic dataset reveals the molecular basis of genotypic variation in hexaploid wheat (T. aestivum L.) in response to Fe/Zn deficiency

Critical assessment of wheat biofortification for iron and zinc: a comprehensive review of conceptualization, trends, approaches, bioavailability, health impact, and policy framework

Addressing global hidden hunger, particularly in women of childbearing age and children under five, presents a significant challenge, with a focus on iron (Fe) and zinc (Zn) deficiency. Wheat, a staple crop in the developing world, is crucial for addressing this issue through biofortification efforts. While extensive research has explored various approaches to enhance Fe and Zn content in wheat, there remains a scarcity of comprehensive data on their bioavailability and impact on human and animal health. This systematic review examines the latest trends in wheat biofortification approaches, assesses bioavailability, evaluates the effects of biofortified wheat on health outcomes in humans and animals, and analyzes global policy frameworks. Additionally, a meta-analysis of per capita daily Fe and Zn intake from average wheat consumption was conducted. Notably, breeding-based approaches have led to the release of 40 biofortified wheat varieties for commercial cultivation in India, Pakistan, Bangladesh, Mexico, Bolivia, and Nepal, but this progress has overlooked Africa, a particularly vulnerable continent. Despite these advancements, there is a critical need for large-scale systematic investigations into the nutritional impact of biofortified wheat, indicating a crucial area for future research. This article can serve as a valuable resource for multidisciplinary researchers engaged in wheat biofortification, aiding in the refinement of ongoing and future strategies to achieve the Sustainable Development Goal of eradicating hunger and malnutrition by 2030.

Wheat Biofortification: Utilizing Natural Genetic Diversity, Genome-Wide Association Mapping, Genomic Selection, and Genome Editing Technologies

Alleviating micronutrients associated problems in children below five years and women of childbearing age, remains a significant challenge, especially in resource-poor nations. One of the most important staple food crops, wheat attracts the highest global research priority for micronutrient (Fe, Zn, Se, and Ca) biofortification. Wild relatives and cultivated species of wheat possess significant natural genetic variability for these micronutrients, which has successfully been utilized for breeding micronutrient dense wheat varieties. This has enabled the release of 40 biofortified wheat cultivars for commercial cultivation in different countries, including India, Bangladesh, Pakistan, Bolivia, Mexico and Nepal. In this review, we have systematically analyzed the current understanding of availability and utilization of natural genetic variations for grain micronutrients among cultivated and wild relatives, QTLs/genes and different genomic regions regulating the accumulation of micronutrients, and the status of micronutrient biofortified wheat varieties released for commercial cultivation across the globe. In addition, we have also discussed the potential implications of emerging technologies such as genome editing to improve the micronutrient content and their bioavailability in wheat.

Comparative physiological, biochemical and transcriptomic analysis of hexaploid wheat (T. aestivum L.) roots and shoots identifies potential pathways and their molecular regulatory network during Fe and Zn starvation

The combined effect of iron (Fe) and zinc (Zn) starvation on their uptake and transportation and the molecular regulatory networks is poorly understood in wheat. To fill this gap, we performed a comprehensive physiological, biochemical and transcriptome analysis in two bread wheat genotypes, i.e. Narmada 195 and PBW 502, differing in inherent Fe and Zn content. Compared to PBW 502, Narmada 195 exhibited increased tolerance to Fe and Zn withdrawal by significantly modulating the critical physiological and biochemical parameters. We identified 25 core genes associated with four key pathways, i.e. methionine cycle, phytosiderophore biosynthesis, antioxidant and transport system, that exhibited significant up-regulation in both the genotypes with a maximum in Narmada 195. We also identified 26 microRNAs targeting 14 core genes across the four pathways. Together, core genes identified can serve as valuable resources for further functional research for genetic improvement of Fe and Zn content in wheat grain.