Mineral Bioavailability in Low Phytic Acid Wheat (Triticum aestivum L.).

Human mineral malnutrition can be exacerbated by consumption of plant tissue and grain with low minerals concentrations and/or high concentrations of antinutrients such as phytic acid (PA). Gpc-B1, a gene introduced to common wheat (Triticum aestivum L.) from T. turgidum var. dicoccoides, is associated with 10 to 15% increase in grain protein content (GPC) in some environments. GPC also has been shown to elevate iron and zinc concentrations. A low PA (LPA) mutant in wheat is now available and has been reported to reduce PA in wheat kernels by up to 35%. However, little is known about the effects of the wheat LPA mutant, alone or in combination with Gpc-B1, on the bioavailability of iron and zinc. Our objective was to evaluate the effect of Gpc-B1 and LPA traits on mineral bioavailability in winter wheat populations. Four genotypes (LPA-GPC, LPA-WT, WT-GPC, and WT-WT) of recombinant inbred lines (RILs) from four Nebraska locations were evaluated for bioaccessibility of minerals using a newly developed in vitro microdigestion and dialysis procedure. There were significant differences among the genotypic groups for bioavailable zinc, calcium and cobalt, but not for iron, copper and manganese content. The LPA allele alone and in combination with the GPC allele significantly increased bioavailable zinc and calcium content. Conversely, the LPA allele alone significantly reduced bioavailable cobalt content, but the effect on this mineral was reversed in the LPA-GPC combination. The dialysis protocol developed can be used effectively in high-throughput systems and our LPA-GPC wheat lines have the potential to be used to biofortify germplasm in other breeding programs.