The major components of wheat storage proteins are gliadins and glutenins, and as they contribute differently to baking quality, a balanced mixture of these components is essential. The application of foliar nitrogen (N) at anthesis is a common practice to improve protein concentration and composition. The aim of this study was to investigate the effects of a foliar N application at anthesis on storage protein gene expression during grain development and on the distribution of protein concentration and protein body size within the grain. In this experiment, an additional N application at anthesis stimulated the expression of genes of the majority of storage proteins when the N supply was low. Furthermore, it led to higher protein concentrations in the subaleurone layers, while in the center of the lobes, the protein concentrations were decreased. These changes will affect the protein recovery in white flours, as proportionally more protein might be lost during milling processes.
Keywords: gene expression; gluten protein; grain protein distribution; protein body size distribution; wheat.