CHANGES IN SOLUBLE SUGARS AND PROTEINS DURING DEVELOPMENT OF RYE COLEOPTILES

An analysis was made of the changes in dry mass, soluble sugars and pr otein complement in coleoptiles of rye seedlings (Secale cereale L.) t hat were either grown in darkness or irradiated with white light. Dry mass and the concentration of soluble sugars (glucose, fructose) incre ased during growth of the juvenile organ. After emergence of the prima ry leaf (cessation of coleoptile elongation) dry mass and sugar conten t decreased. Cytoplasmic proteins have been extracted from growing and non-growing (mature) coleoptiles and separated by gel electrophoresis . Examination of the silver stained profiles of polypeptides revealed only minor changes, i.e. no loss of protein was detected. Because prot ein breakdown is a main characteristic of senescence, we conclude that the pierced coleoptile is a mature, metabolically active organ that p rovides carbohydrates for the growing parts of the developing seedling .