Journal of Energy Bioscience 2025, Vol.16, No.3, 139-150 http://bioscipublisher.com/index.php/jeb 145 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).
RkJQdWJsaXNoZXIy MjQ4ODYzNA==