1 Introduction

Many people around the world are now deficient in micronutrients, especially iron. Iron deficiency anemia has become a serious public health problem. This problem is most common among women and children in developing countries (Taskın and Gunes, 2022; Gupta et al., 2024; Tanin et al., 2024). Iron deficiency is not only harmful to the body, but also affects intellectual development. People's work efficiency becomes lower and their quality of life also declines. Therefore, how to get everyone to consume more iron is an important task in global nutrition work (Gupta et al., 2024; Tanin et al., 2024).

Biofortification is a way to improve the nutrition of staple food. There are two main ways: one is agronomic measures, such as fertilization, leaf spraying, and seed treatment; the other is through breeding, such as traditional breeding, molecular breeding, and the newer gene editing (Ludwig and Slamet-Loedin, 2019; Zulfiqar et al., 2020; Tanin et al., 2024; Gupta et al., 2024; Zhou et al., 2024). Compared with taking nutritional supplements or fortified foods, biofortification is to add nutrients when planting. This method is more cost-effective and more sustainable, especially for areas with fewer resources (Ludwig and Slamet-Loedin, 2019; Gupta et al., 2024; Tanin et al., 2024). Scientists have also found that using microorganisms to help crops absorb iron is also an environmentally friendly and effective new method (Shi et al., 2020; Sun et al., 2021).

Wheat is one of the most important grains in the world. It is grown in Asia, Africa, Europe and America. Many people get their daily energy and protein from wheat (Ludwig and Slamet-Loedin, 2019; Gupta et al., 2024; Tanin et al., 2024). But the problem now is that most wheat varieties do not have high iron content. Iron is mainly concentrated in the bran, and many people eat processed white flour, which loses a lot of iron. Therefore, people who eat wheat for a long time are more likely to be iron deficient (Ludwig and Slamet-Loedin, 2019; Gupta et al., 2024). Increasing the iron content in wheat grains and making it easier for the human body to absorb this iron are the keys to solving the problem of iron deficiency (Ludwig and Slamet-Loedin, 2019; Gupta et al., 2024; Tanin et al., 2024).

This study mainly introduces the latest research results in wheat iron biofortification. The content includes many methods, such as soaking seeds in liquid, spraying fertilizers on leaves, using nanofertilizers, as well as traditional and molecular breeding, gene editing, and using microorganisms to help. We will also evaluate the effectiveness of these methods in improving the iron content, yield and absorption efficiency in wheat. The article will also analyze the actual application of these methods in combination with some real cases, and propose possible future research directions.

2 Iron Deficiency and Public Health Impact

2.1 Epidemiological data: Prevalence of iron deficiency in developing vs. developed nations

Iron deficiency is one of the most common nutritional problems in the world today, affecting nearly 2 billion people. It is one of the main causes of many diseases (Zimmermann and Hurrell, 2007). In developing countries, iron deficiency anemia is already very common, especially among children aged 0 to 5 and women of childbearing age (Kumar et al., 2022; Manish, 2025). According to data from the World Health Organization in 2019, about 1.62 billion people suffer from anemia, and most of them are caused by iron deficiency (Manish, 2025). Although the iron deficiency rate in developed countries is lower than that in developing countries, in some countries like the United States, many pregnant women and children still suffer from iron deficiency anemia (Jefferds et al., 2022; Manish, 2025).

2.2 Vulnerable populations: Children, pregnant women, and the elderly

Iron deficiency mainly affects children, pregnant women, women of childbearing age and the elderly (Pasricha et al., 2020; Benson et al., 2021; Chouraqui, 2022; Iriarte-Gahete et al., 2024; Manish, 2025). Children and adolescents are in the growth and development stage and need a lot of iron (Chouraqui, 2022). If they do not eat enough, they are prone to iron deficiency. Pregnant women are also prone to iron deficiency or even anemia because their bodies need more iron, which will affect the health of mothers and fetuses (Benson et al., 2021; Manish, 2025). Elderly people and some patients with chronic diseases (such as heart patients) are also common in iron deficiency, which can make symptoms more severe and reduce the quality of life (Von Haehling et al., 2015).

2.3 Consequences: Cognitive impairment, reduced productivity, maternal mortality

Iron deficiency not only causes anemia, but also causes many other problems. Children may have slow intellectual development, poor motor skills, poor learning, and reduced resistance (Zimmermann and Hurrell, 2007; Benson et al., 2021; Chouraqui, 2022; Kumar et al., 2022; Bjørklund et al., 2024; Manish, 2025). Adults may feel tired and weak, and their work efficiency will also decrease. If pregnant women are iron deficient, they may have poor pregnancy outcomes, such as a higher risk of death or cognitive problems in their babies after birth (Zimmermann and Hurrell, 2007; Benson et al., 2021). If patients with chronic diseases are iron deficient, their conditions may worsen and recovery will be more difficult (Von Haehling et al., 2015).

2.4 Current interventions and their limitations: Supplementation, fortification, and food diversification

There are three common methods now: taking iron supplements, eating fortified foods, and changing the diet structure to consume more iron (Zimmermann and Hurrell, 2007; Chouraqui, 2022; Kumar et al., 2022; Manish, 2025). Iron supplements are effective and are the most commonly used treatment, but taking too much may have side effects, such as stomach discomfort. In addition, when there is inflammation, the body's absorption of iron will also deteriorate (Pasricha et al., 2020; Iriarte-Gahete et al., 2024). Fortified foods, such as iron-added flour and infant formula, are helpful in controlling iron deficiency, but there are still many technical difficulties, such as iron is not easily absorbed by the body (Zimmermann and Hurrell, 2007; Chouraqui, 2022). A diverse diet can also increase iron intake, but in many low-income areas, it is not easy to eat this way, and it is also limited by economic conditions and eating habits (Chouraqui, 2022; Kumar et al., 2022). There are some problems with current testing methods, such as insufficient sensitivity or incomplete data, which also makes it difficult for high-risk groups to be detected in time, thereby delaying intervention (Benson et al., 2021; Jefferds et al., 2022).

3 Biological Mechanisms of Iron Uptake, Transport, and Storage in Wheat

3.1 Soil-to-root uptake mechanisms: Strategy II (chelation strategy in grasses)

Wheat is a grass plant that absorbs iron mainly through the "Strategy II" mechanism. When iron is deficient, wheat roots turn on some special genes that allow the plant to produce more substances called plant siderophores (PS), especially DMA. These PS molecules are secreted into the soil by the roots, where they can grab Fe(III) in the soil and turn it into a complex that the plant can absorb. Genes like NAS and DMAS become particularly active when iron is deficient. They help synthesize and transport these small iron-grabbing molecules, making it easier for wheat to absorb iron from the soil (Wang et al., 2019; Wang et al., 2020).

3.2 Transport systems: Role of YS1/YSL transporters, ZIP family proteins

Once iron is absorbed by the roots, it has to rely on the transport system in the body to transport it to other parts, such as leaves and grains. In this process, some special proteins play a key role. YS1 and YSL proteins can transport small molecules linked to iron, such as Fe-NA or Fe-DMA, across the cell membrane. They are particularly important in long-distance transport from roots to leaves and leaves to grains. Proteins of the ZIP family also help iron move back and forth between cells. In addition, proteins such as NRAMP and MFS are also involved in the redistribution of iron to keep the body's iron in balance (Connorton et al., 2017; Wang et al., 2019; Wang et al., 2020).

3.3 Iron storage: Ferritin localization, iron distribution in wheat grain

Iron is not randomly distributed in wheat grains, but has a certain location. It is mostly stored in cells in the form of ferritin, especially concentrated in the organelles of the aleurone layer and endosperm. Using some imaging techniques and isotope labeling methods, studies have found that iron is transported along the symplasmic route and finally accumulates in the aleurone layer, endosperm and embryo. If wheat is allowed to express more iron transport proteins like TaVIT2, the iron content in the grain, especially the white flour part, can be increased without increasing anti-nutritional components such as phytate (Connorton et al., 2017; Sheraz et al., 2021).

3.4 Genomic insights: Key genes/QTLs involved in iron homeostasis

The mechanism by which wheat regulates iron content is related to many genes and QTLs (quantitative trait loci). When iron is deficient, some genes responsible for absorbing, transporting and storing iron will be "turned on", such as NAS, DMAS, TOM, YSL, NRAMP and bHLH. The transcription factors of the bHLH family are very critical in this process. They regulate the expression of other genes like switches. Now, through QTL analysis and genome-wide association studies (GWAS), many gene loci related to grain iron content have been found. These results also provide new directions and targets for future wheat breeding (Wang et al., 2020; Tanin et al., 2024) (Figure 1).

4 Biofortification Strategies for Wheat

4.1 Agronomic biofortification

4.1.1 Iron fertilizers (soil and foliar)

Agronomic biofortification mainly relies on the application of iron fertilizers, such as ferrous sulfate, iron chelates, and nano-iron fertilizers. Foliar iron fertilizer spraying wheat can increase the iron content in the grain, with an average increase of 18.2%. Direct application to the soil is also effective, with an increase of about 26.7% (Zhou et al., 2024). Before the wheat blooms, if more sprays are made and the concentration is slightly higher (for example, more than 0.1%), the effect will be better. If 1% ferrous sulfate and urea are sprayed on the leaves together, the iron content in the grain can reach up to 50 mg/kg, which is a very effective method (Ramzan et al., 2020; Taskın and Gunes, 2022). Soaking seeds with iron nanoparticles can also promote better wheat growth and more iron accumulation (Sundaria et al., 2019; Zulfiqar et al., 2020).

4.1.2 Role of chelators and plant growth conditions

Iron chelators, such as Fe-EDDHA, can make iron in the soil more easily absorbed by plants (Taskın and Gunes, 2022). The method of retaining the surface and not tilling the soil, such as "zero tillage", can increase the organic matter and microorganisms in the soil, and indirectly help wheat absorb iron (Zulfiqar et al., 2020). If zinc and iron are sprayed at the same time (such as 0.5% zinc sulfate plus 1% ferrous sulfate), not only can the yield be increased, but the quality of the grain will also be better (Ramzan et al., 2020).

4.2 Conventional breeding

4.2.1 Screening of landraces and wild relatives

Conventional breeding is to select local wheat varieties with high iron content or its "wild relatives", and then slowly cultivate new varieties with high iron content. In countries like India and Pakistan, more than 40 high-iron wheat varieties have been promoted through this method (Gupta et al., 2024). At present, there are not many high-quality high-iron gene resources, which also limits the further development of conventional breeding in this regard (Ludwig and Slamet-Loedin, 2019; Tanin et al., 2024).

4.2.2 QTL mapping and marker-assisted selection

Molecular breeding techniques, such as QTL positioning, Meta-QTL analysis and GWAS research, have been used to study the genetic basis of wheat iron content. These methods also help scientists find genes related to "high iron" more quickly (Ludwig and Slamet-Loedin, 2019; Tanin et al., 2024). Through molecular marker-assisted selection (MAS), these good genes can be combined more quickly to cultivate a new generation of high-iron wheat (Ali and Borrill, 2020; Tanin et al., 2024) (Figure 2).

4.3 Transgenic approaches

4.3.1 Overexpression of ferritin genes (soybean, rice)

Some methods add ferritin genes from other plants, such as soybeans or rice, into wheat. This method can significantly increase the iron content in the grain (Ludwig and Slamet-Loedin, 2019; Tanin et al., 2024). There have been successful cases in rice, and wheat can also learn from this method (Ludwig and Slamet-Loedin, 2019).

4.3.2 Manipulation of NAAT and NAS genes

Another way is to regulate the genes responsible for iron transport in wheat itself, such as NAAT and NAS. This allows wheat to absorb and accumulate more iron, and the iron content in the grain will also increase (Ludwig and Slamet-Loedin, 2019; Tanin et al., 2024).

4.4 Gene editing (CRISPR/Cas9): Targeted modifications for iron accumulation

Gene editing tools such as CRISPR/Cas9 can accurately "cut and modify" key genes in wheat, such as those that control iron absorption, transportation, and storage. It does not require the introduction of foreign genes to turn wheat into a "new high-iron variety". It is a very promising method and is more easily accepted by the public (Ludwig and Slamet-Loedin, 2019; Tanin et al., 2024).

5 Factors Affecting Bioavailability of Iron in Wheat Grains

5.1 Phytate content: Its role as an anti-nutrient and strategies to reduce it

Phytic acid is the main "anti-nutritional factor" in wheat grains. It binds to iron, making it more difficult for the body to absorb the iron (Singh et al., 2013; Abid et al., 2017; Huyskens et al., 2025). Abid et al. (2017) found that adding the phytase gene to wheat can reduce the phytic acid in the grain, making iron and zinc easier to absorb. The phytic acid content of these transgenic wheats can be reduced by up to 76%, and the utilization rate of iron can be greatly improved. In addition to transgenic, some simple treatment methods are also useful, such as heat treatment. If hydrothermal treatment with citric acid buffer is used, the absorption rate of iron can be increased by 6 times compared to the original (Huyskens et al., 2025). Some studies have also pointed out that the relationship between phytic acid and iron may be different for different wheat varieties. Wright et al. (2021) found through research that sometimes, even if phytic acid is reduced, iron absorption remains unchanged. This shows that simply reducing phytic acid may not be enough.

5.2 Polyphenols and other inhibitors

In addition to phytic acid, wheat also contains polyphenols and other "blockers" that can also affect iron absorption (Singh et al., 2013; Tanin et al., 2024). These substances form insoluble complexes with iron, making iron difficult to absorb. The distribution of iron in the grain and its combination with elements such as phosphorus and sulfur will also affect the body's utilization of iron. Different varieties of wheat may have different locations of iron in their bodies, which can also lead to different absorption effects (Singh et al., 2013).

5.3 Enhancers of iron absorption: Ascorbic acid, citric acid

Some substances are in turn "good helpers" that can help the body absorb iron better. For example, ascorbic acid (vitamin C) and citric acid are common factors that promote iron absorption. Citric acid can reduce the effects of phytic acid and combine with iron to form a soluble complex, which makes iron easier to absorb by the body (Huyskens et al., 2025). Studies have also found that when citric acid is added during hydrothermal treatment, the absorption rate of iron can be increased by nearly 10 times, indicating that it has great potential in fortified foods.

5.4 Processing methods: Milling, fermentation, parboiling.

How wheat is processed can also affect iron absorption. Grinding (especially fine grinding) can break down cell walls, making the iron inside easier to release (Aslam et al., 2024). Fermentation and pre-cooking are also useful. They can break down phytic acid and other substances that hinder iron absorption, thereby improving iron utilization (Abid et al., 2017; Diego Quintaes et al., 2017). If heat-treated with citric acid water, iron absorption can be greatly improved (Huyskens et al., 2025). Some traditional processes, such as fermentation and baking, have also been shown to help iron absorption (Diego Quintaes et al., 2017).

6 Breeding Progress and Available Iron-Rich Wheat Varieties

6.1 Notable varieties released globally: e.g., India’s WB02 and WB03

In recent years, many countries have successfully launched high-iron wheat varieties through biofortification breeding. For example, India has released 40 such varieties, including WB02 and WB03. These wheats have been promoted for cultivation in India, Pakistan, Bangladesh, Mexico, Bolivia and Nepal (Gupta et al., 2024). Nepal also launched 5 new varieties in 2020. These wheats are not only high-yielding and disease-resistant, but also have 30% to 40% higher iron and zinc content than ordinary wheat (Thapa et al., 2022). In addition, South Asia and Mexico have also developed a number of wheat varieties with high iron and zinc content (Velu et al., 2019).

6.2 Yield vs. nutrition trade-offs

In the breeding process, how to improve yield and nutrition at the same time has always been a difficult problem. Some experiments have shown that there is not much relationship between iron and zinc content and yield, and sometimes it may even be a bit opposite (Govindan et al., 2022; Thapa et al., 2022; Wani et al., 2022). However, through purposeful hybridization and screening of large populations, some high-yield and iron-rich strains have been selected. These strains can improve nutrition and yield together (Velu et al., 2019; Govindan et al., 2022; Thapa et al., 2022). The yield of some high-iron and high-zinc wheat can reach or exceed 95% to 110% of ordinary varieties (Velu et al., 2019).

6.3 Multi-location trials and stability

To know whether a variety is stable and suitable for different places, you have to do multi-point field trials for many years. The results showed that different locations and years will affect yield and iron and zinc content. However, most biofortified wheats are stable in multiple locations and have strong genetics (Govindan et al., 2022; Thapa et al., 2022). In 2022, Govindan's team found in a trial in Nepal that the iron and zinc levels in different places are indeed different, but these high-iron varieties are better than ordinary varieties in terms of yield and nutrition (Thapa et al., 2022).

6.4 Role of CGIAR and HarvestPlus programs

CGIAR's CIMMYT (International Maize and Wheat Improvement Center) and the HarvestPlus project have played an important role in the global promotion of biofortified breeding. HarvestPlus and global partners have released or tested 393 biofortified crop varieties, covering 63 countries and helping more than 48 million people (Cakmak et al., 2010; Virk et al., 2021; Kumar et al., 2023). CIMMYT and other CGIAR institutions are also using new methods such as high-throughput phenotyping, genomic selection, and rapid breeding to promote the promotion of high-iron and high-zinc wheat (Virk et al., 2021; Govindan et al., 2022; Wani et al., 2022). These international collaborations not only bring new wheat varieties, but also support nutrition research, policy making, and impact assessment, contributing to global food and nutrition security (Cakmak et al., 2010; Virk et al., 2021; Kumar et al., 2023).

7 Genomic and Transcriptomic Tools in Iron Biofortification

7.1 Genome-wide association studies (GWAS)

GWAS is a method that can help us find "iron-related gene regions" in wheat. Using this method, researchers conducted detailed genotyping tests (such as SNP typing) on ​​many different types of wheat, and recorded their iron content performance in different environments. The results showed that some specific DNA markers were related to iron content, and these markers (MTA) were distributed on multiple chromosomes. They are close to some key iron-related genes, such as iron transporters, F-box proteins, multidrug excretion proteins, and zinc finger proteins. These research results not only allow us to better understand how iron is regulated in wheat, but also provide useful molecular tools for the next step of breeding high-iron wheat (Krishnappa et al., 2022; Wani et al., 2022).

7.2 RNA-seq and gene expression profiling under iron-deficient conditions

RNA-seq can be used to analyze the gene expression of wheat under iron deficiency and non-iron deficiency conditions. By comparing the transcriptomes under the two conditions, scientists found many genes that are "turned on" when iron is deficient. These genes mainly include iron transport proteins, enzymes that synthesize iron chelators (such as NAS, YSL and ZIP families) and related metabolic pathways. These genes with changed expression help us understand more clearly how wheat copes with iron deficiency. They are also potential targets for future gene editing or molecular breeding (Mallikarjuna et al., 2020; Wani et al., 2022).

7.3 CRISPR-Cas9 validation of candidate genes

Now with gene editing tools such as CRISPR-Cas9, scientists can directly "modify" genes that may be related to iron content. They can choose to knock out a gene or make it express more. Doing so can directly see whether these genes have an effect on the iron content of the grain. This method not only speeds up the verification, but also provides a very practical tool for the precise improvement of high-iron wheat in the future (Borrill et al., 2014; Wani et al., 2022).

7.4 Integration with phenotyping platforms

Now there is also a very effective way, which is to combine the phenotypic platform with genetic data. Scientists will measure the iron content of a large number of wheat materials in many locations and different years, and then analyze these data together with GWAS results, RNA-seq analysis, and gene editing results. This will help find useful genes more quickly and select excellent varieties more accurately. This combination of "gene + phenotype" makes the breeding of high-iron wheat more efficient and systematic (Lung'aho et al., 2011; Velu et al., 2016; Wani et al., 2022).

8 Challenges and Knowledge Gaps

8.1 Yield penalty and pleiotropic effects

When breeding iron-fortified wheat, one of the biggest problems is how to increase iron content and yield at the same time. Sometimes these two goals will "fight" because they are controlled by many genes and the relationship is relatively complex. Although some QTLs can increase iron content, it takes a lot of time to breed them to maintain this advantage in a high-yield background (Wani et al., 2022). Those iron-related genes may also affect other agronomic traits, such as how fast wheat grows and how strong its disease resistance is. This "pleiotropic effect" is not yet fully understood and needs to be further systematically studied (Ali and Borrill, 2020; Wani et al., 2022; Tanin et al., 2024).

8.2 Consumer and regulatory acceptance (especially of GM varieties)

Although gene editing and transgenic technologies can help us quickly breed high-iron wheat, many consumers and regulatory authorities still have concerns about transgenic crops. Especially in some countries, people are not very receptive to such crops (Ali and Borrill, 2020; Gupta et al., 2024). In addition, policy and market uncertainties, such as complex approval processes and many market restrictions, also make it difficult to promote genetically modified wheat. In addition, many people are also worried about whether genetically modified foods will affect health, so it is even more necessary to strengthen popular science publicity and safety assessment (Gupta et al., 2024).

8.3 Environmental variability: soil pH, microbiome effects

Whether wheat can absorb iron is also related to the planting environment. For example, the pH of the soil, the type of soil, and the microorganisms around the roots will affect the absorption of iron (Taskın and Gunes, 2022; Shi et al., 2020). In different soils, the "availability" of iron is different, and the absorption efficiency of wheat roots will also change. Microorganisms such as bacteria and fungi in the rhizosphere can sometimes help plants absorb and transport iron, but we don’t know much about these mechanisms, especially in real fields, which is even more difficult to predict (Shi et al., 2020).

8.4 Trade and intellectual property barriers

There are still many policy and regulatory "blocking points" to promote iron-fortified wheat globally. Countries have different standards for the approval of new varieties, the ownership of seeds, and whether they can be freely circulated, which brings a lot of difficulties to international promotion (Gupta et al., 2024). In some developing countries, such as Africa, the commercialization of iron-fortified wheat is still relatively slow. This is not only a technical problem, but also related to policies and trade barriers. To solve these problems, countries need to strengthen cooperation and promote policy coordination.

9 Case Study: Success Story of Iron-Biofortified Wheat in India

9.1 Institutional collaboration: HarvestPlus, ICAR, IARI

India’s successful promotion of iron-fortified wheat is inseparable from the cooperation of multiple institutions. HarvestPlus, the Indian Council of Agricultural Research (ICAR), and the Indian Agricultural Research Institute (IARI) are all involved in this process. These institutions have worked together on breeding, promotion, and policy support. Through resource integration and technology sharing, they have promoted the research and development and large-scale application of iron-fortified wheat, helping India lay the foundation for nutritional security (Kamble et al., 2022; Gupta et al., 2024).

9.2 Breeding process: Use of donor parents and marker-assisted selection

During the breeding process, researchers first selected parent materials with high iron content. Then, molecular marker technology was used to help speed up screening, combine good traits together, and make breeding more efficient. Genotypes such as HP-06 and HP-22 have high iron and zinc contents and are suitable for continued use as breeding parents (Kamble et al., 2022; Sheera et al., 2023; Gupta et al., 2024).

9.3 Field performance and adoption: Yield comparison, farmer acceptance

Some iron-fortified wheat varieties perform well in the field, such as HD 3298 and HI 8802. Not only are they high in iron content (HD 3298 has 43.1 ppm), they also have high yields and can adapt to harsh environments. Even when sown very late, HD 3298 can still produce 47.4 quintals/hectare, and HI 8802 has performed better than ordinary varieties in multiple local trials (Yadav et al., 2022; Singh et al., 2022). These varieties are nutritious, easy to grow, and accepted by farmers, and were quickly promoted throughout India (Kamble et al., 2022; Singh et al., 2022; Yadav et al., 2022).

9.4 Nutritional outcomes: human trials showing improved iron status

Studies have shown that after replacing ordinary wheat with iron-fortified wheat, people eat a lot more "absorbable iron". Simulation data show that this will increase the available iron in the diet by 28%, and about 22.6 million people (almost 8% of the total population) will be freed from insufficient iron intake (Dhillon et al., 2008). Iron-fortified wheat is really useful in helping to solve the problem of iron deficiency (Dhillon et al., 2008; Gupta et al., 2024).

9.5 Lessons learned: scalability, supply chain, policy support

Based on India’s experience, the large-scale promotion of iron-fortified wheat requires the coordination of several aspects: breeding must keep up, seed supply must be smooth, government support must be provided, and multiple institutions must work together (Kamble et al., 2022; Gupta et al., 2024; Ram et al., 2024). More efforts must be made in the future, such as improving supply chain management, ensuring continuous policy support, and conducting long-term evaluations of the effects of nutritional improvement. Only in this way can iron-fortified wheat be promoted for a long time and truly improve people’s health (Kamble et al., 2022; Gupta et al., 2024; Ram et al., 2024).

10 Future Perspectives and Policy Implications

The technology for iron-fortified wheat is advancing rapidly. New technologies such as bioinformatics and synthetic biology now make it easier to find genes related to iron, analyze their effects, and modify them precisely. These tools are expected to solve wheat's problems in absorbing, transporting, and storing iron.

Some new inputs, such as nanofertilizers, are also thought to make iron more accessible to plants. At the same time, the use of microorganisms to help wheat absorb iron, combined with gene editing and multi-omics data, is also accelerating the breeding process, making iron fortification more efficient and precise. But relying on just one breeding method may not be enough. Combining traditional breeding, molecular breeding, and field management measures, such as using biofertilizers or conditioning soil methods, can improve the iron content and absorption rate in wheat grains. We can also use the combination of engineered microorganisms and plant genes to make wheat more likely to accumulate and transport iron, providing a new direction for the next step of comprehensive fortification.

In order to truly promote iron-fortified wheat, efforts from all parties are needed. Governments, companies, and research institutions can promote the promotion and large-scale planting of new varieties through "public-private partnerships" (PPPs). At the same time, through popular science and nutrition education, more consumers can understand and accept such crops, which can help the market grow faster. Countries like India and Pakistan have already commercialized 40 iron-fortified wheat varieties. However, in some high-risk areas such as Africa, this technology has not been widely used and needs more promotion and support.

We can introduce some encouraging policies, such as subsidies for farmers to grow iron-fortified wheat and support for enterprises to promote new varieties. At the same time, more money should be invested in basic research and technology applications to transform new achievements into real productivity as soon as possible. A more complete regulatory system should also be established to ensure that these new crops are safe, effective and sustainable. By strengthening international cooperation, it can also help some resource-deficient regions to fill the technological gap and jointly promote global nutrition security.

Iron biofortification is a good way to solve "hidden hunger". It not only helps improve health, but also has economic and social benefits. As long as we continue to work hard in science, technology, policies and management, it is entirely possible that iron-fortified wheat will be widely promoted around the world and contribute to reducing malnutrition and achieving sustainable development goals.

Acknowledgments

We would like to express our gratitude to the two anonymous peer researchers for their constructive suggestions on our manuscript.

Conflict of Interest Disclosure

The authors affirm that this research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest.

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