Biofortification of hard red winter wheat by genes conditioning low phytate and high grain protein concentration

Authors: VENEGAS, JORGE - University Of Nebraska; Graybosch, Robert; Wienhold, Brian; ROSE, DEVIN - University Of Nebraska; WATERS, BRIAN - University Of Nebraska; BAENZIGER, PETER - University Of Nebraska; ESKRIDGE, KENT - University Of Nebraska; Bai, Guihua; St Amand, Paul

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2018
Publication Date: 7/26/2018
Citation: Venegas, J.P., Graybosch, R.A., Wienhold, B.J., Rose, D.J., Waters, B.M., Baenziger, P.S., Eskridge, K., Bai, G., St Amand, P.C. 2018. Biofortification of hard red winter wheat (Triticum aestivum L.) by genes conditioning low phytate and high grain protein concentration. Crop Science. 58(5):1942-1953. https://doi.org/10.2135/cropsci2018.03.0175.
DOI: https://doi.org/10.2135/cropsci2018.03.0175

Interpretive Summary: Iron deficiency occurs in approximately 60% of the world’s human population, while zinc deficiencies occur in over 30%. This situation is attributed to production areas with low mineral phytoavailability, and consumption of staple crops with low mineral concentrations and/or high concentrations of antinutrients such as phytate. Experimental lines of winter wheat were used to determine whether combining a mutation conditioning low phytate (LPA) with a second mutation (GPC) alleged to provide higher grain protein would simultaneously boost beneficial mineral concentrations and grain protein without negative effects on grain yield. Results indicated LPA and GPC combined did not lower grain yield, grain protein, or total grain Fe and Zn concentrations. Unfortunately, the LPA-GPC combination significantly reduced grain volume weight. This could have a negative economic effect unless the grain volume weight deficit could be overcome by breeding. The LPA allele alone reduced grain protein concentration. LPA alone and in combination with GPC increased potential bioavailable Zn, Ca and Mn. introgression of the Gpc-B1 and lpa1-1 alleles into adapted Great Plains winter wheat materials can increase grain protein and dialyzed Zn, Ca and Mn concentrations without reducing grain yield.

Technical Abstract: Recombinant inbred lines (RILs) of winter wheat (Triticum aestivum L.) were used to determine whether the combination of low grain phytate (LPA) conditioned by lpa1-1, and Gpc-B1 (GPC- grain protein content) alleles would simultaneously increase beneficial mineral concentrations and grain protein without pleiotropic effects on grain yield. Four different genotypes (LPA-GPC, LPA-WT, WT-GPC, or WT-WT) were used as treatments in field experiments in Nebraska. Genotypic effects on senescence, grain yield, grain volume weight, and grain protein, Fe, Zn, and other mineral grain concentrations were determined. Results indicated LPA and GPC combined did not lower grain yield, grain protein, or total grain Fe and Zn concentrations. However, the LPA-GPC combination significantly reduced grain volume weight. The LPA allele alone reduced grain protein concentration. LPA alone and in combination with GPC increased dialyzed Zn, Ca and Mn. Gpc-B1 had a slight effect on grain protein concentration in the tested genetic backgrounds and environments. Introgression of lpa1-1 alleles into adapted Great Plains winter wheat materials can improve dialyzed Zn, Ca and Mn concentrations without reducing grain yield, and, coupled with introgression of Gpc-B1, provide more nutritious wheat kernels.