Effect of various doses of zinc and nitrogen applied at different times on wheat grain zinc concentration

Increasing zinc (Zn) concentration of cereal grains is a global challenge to alleviate Zn deficiency-related health problems in humans caused by low dietary Zn intake. The number of studies on the crucial role of nitrogen nutrition on plants Zn and Fe uptake, transportation and accumulation is increasing.This study was focused on the potential of N fertilization in biofortification of wheat grain based on the assumption that N nutrition is affecting transporter proteins along with other nitrogen bearing molecules which involved in Zn and Fe uptake, transportation and accumulation. For this purpose, wheat plants were grown with different N and Zn treatments at greenhouse and field conditions.According to the results of field and greenhouse trials; grain Zn concentration was greatly enhanced by soil or foliar applied zinc. Similar to Zn increase, treatments also affected N and Fe concentrations of grain. When Zn was adequately supplied, both soil and foliar N applications improved grain zinc concentration. Under greenhouse conditions, with sufficient Zn treatment along with high N application contributed to the the uptake and remobilization of Zn and Fe from vegetative tissues. Under field conditions, the positive effect of adequate N nutrition on remobilization of micro elements might be more relevant, when uptake is limited during grain development due to drought or any other stress condition.