EN
Maturation of Norway maple (Acer platanoides L.) seeds produces deep physiological dormancy and resistance to desiccation. This study used two-dimensional electrophoresis to investigate the protein products of genes activated during the complex developmental process of maturation. Qualitative and quantitative changes in protein composition during maturation were tracked in this species. The most intensive changes in protein content appeared at the end of seed maturation, in embryo axes and cotyledons. During this time their protein content increased significantly and new proteins appeared. Presumably the proteins Q (15 kDa, pI 8) and X (16 kDa, pI 5) separated from cotyledons are associated with maturation of seeds.