Roles of nitrogen and zinc nutrition in biofortification of wheat grain

Official URL: http://192.168.1.20/record=b1302948 (Table of Contents)

Deficiencies of zinc (Zn) and iron (Fe) are widespread nutritional problems, caused mainly by low dietary intake. Biofortification of cereal grains with Zn and Fe in order to alleviate the health problems associated with these deficiencies is a global challenge. Based on the hypothesis that nitrogen (N) nutrition may affect the transporter proteins and other nitrogenous molecules which are involved in root uptake, root-to-shoot transport, remobilization, phloem transport and grain accumulation as well as grain localization of Zn and Fe, the potential of N fertilization in biofortification of wheat grain was investigated in this project. For this purpose, wheat plants were grown with different N and Zn treatments under greenhouse or growth chamber conditions. Increasing N application improved the grain Zn and Fe concentrations by up to 100%. This impact of N on grain Zn concentration disappeared at low Zn supply, whereas the combination of high N and Zn treatments gave rise to synergistic results. Under high Zn availability, higher N supply increased the shoot Zn and Fe contents by up to 300%, indicating a tremendous enhancement in root uptake. Higher N application also led to a 240% increase in Zn and 70% increase in Fe remobilization to grains. Improving the N nutrition enhanced the Zn and Fe concentrations not only in the whole grain but also the endosperm, the most widely consumed part of wheat grain. As an agronomic biofortification tool, optimized N applications may rapidly and effectively contribute to the mitigation of Zn and Fe deficiency problems in developing countries.