Germination-induced Changes in Chromosomal Proteins of Spring and Winter Wheat Embryos

The template activity of chromatin from winter wheat embryos gradually increased during germination and was regulated with some nonhistone proteins different from the two major ones, molecular weight 39k and 59k polypeptides, previously reported.To clarify chromosomal proteins which are involved in regulation of template activity of chromatin, we studied the quantitative and qualitative changes in chromosomal proteins. Differences in acid-soluble and acid-insoluble proteins between chromatins from wheat germ and embryos germinated for various times were visualized by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis.Nonhistone proteins of 39k, 41k, and 50k molecular weights were specifically present in wheat germ and in 24- or 48-hour germinated wheat embryos, thereafter greatly reduced or finally disappeared. In contrast, nonhistone protein of 37k was absent in germ and in embryos germinated for 24 hours and appeared after 48 hours of germination. Thereafter it was present in abundant amounts in 96-hour germinated winter wheat embryos and in 72-hour germinated spring embryos, corresponding to 7 and 10% of total nonhistone proteins, respectively. Histone H1, especially H1d, was slightly reduced after 48-hour germination, as much as basic nonhistone proteins having electrophoretic mobilities between H1d and H2B. Further-more, similarity and diversity of chromosomal proteins between spring and winter wheat embryos are shown in this study. A subspecies of histone H1c of spring wheat had faster electrophoretic mobility than that of winter wheat.