Department of Plant Sciences

More than half the world’s population is at moderate to high risk of zinc (Zn) deficiency, and biofortification has become an important strategy to alleviate the problem. Grain loading is likely to be a major bottleneck in cereal biofortification. However, very little is known about the transporters involved in this process. We have used barley as a model system to study the transporter genes which are potentially important in grain Zn loading. Here we report effect of over-expressing a barley ZIP gene in barley on grain Zn content. Our results showed that when the transgenic plants were grown at low Zn supply, grain Zn concentrations of transgenic lines were not different from those of the null lines, but with a low dose of Zn supplement during anthesis grain Zn content in transgenic lines increased by 50%. When plants were grown at a high Zn supply, grain Zn concentration of the transgenic lines was doubled relative to the null lines and wildtype. The enhanced concentration of Zn in the grain of the transgenic plants did not alter concentrations of other micronutrients. These results indicate that the constitutive expression of HvZIP7 could specifically increase grain Zn content.