Targeting candidate genes for the macronutrient accumulation of wheat grains for improved human nutrition

Wheat biofortification represents a promising avenue to combat global micronutrient deficiencies. Therefore, understanding the genetic basis of desirable alleles underpinning all minerals is important for wheat biofortification. A core collection of 111 wheat genotypes was evaluated for both years to measure macronutrient contents, including magnesium (Mg), calcium (Ca), phosphorus (P), and potassium (K). Our study showed significant natural phenotypic variation for all of the studied macronutrients underlying both years with high heritability values. Using a genome-wide association scan (GWAS), 474 significant SNP markers were detected and associated with all the evaluated macronutrients for both years. Upon GWAS analysis, several reliable genomic regions with different potential candidate genes were found to play essential roles in the biofortified wheat grains. For instance, the gene TraesCS1A02G261200 was located on chromosome 1A and annotated as calcium ion binding proteins. These proteins play a crucial role in regulating mineral accumulation in wheat grains by influencing signal transduction, mineral transporter regulation, stress responses, cell wall stability, seed development, and enzymatic activity modulation. Notably, the accessions carrying T allele showed a higher accumulation of Mg, P, and Ca in wheat grains than the accessions carrying C allele, suggesting the positive selection of the accessions carrying T allele in the wheat panel. Therefore, exploring the mechanisms and regulation of these proteins could lead to techniques for enhancing the nutritional value of wheat grains, specifically mineral content.