The starchy endosperm of wheat, Triticum aestivum, has three major components: protein, starch and cell wall polysaccharides, which are are not homogenously distributed across the tissue. Using antibodies for specific gluten protein types, Tosi et al. find that quantitative and qualitative gradients in gluten protein composition are established during grain development. These gradients may be due to the origin of subaleurone cells, or could result from the action of specific regulatory signals produced by the maternal tissue on specific domains of the gluten protein gene promoters.
