Effect of the phenylurea cytokinin 4-PU-30 on the growth and protein composition of maize seedlings

The action of the phenylurea cytokinin 4-PU-30 on maize seedling growth, photosynthetic parameters, and leaf protein composition was investigated. The applied phenylurea cytokinin increased leaf growth and photosynthetic activity of the seedlings. It also elevated chlorophyll and total nitrogen content in leaves, as well as the quantity of individual protein fractions. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDSPAGE) of soluble proteins (albumins plus globulins) revealed four protein polypeptides with molecular masses of 27,000, 24,000, 17,000, and 15,000. Comparison of the polypeptides from treated plants with relevant polypeptides from control plants showed some significant, quantitative differences. New proteins, of similar molecular mass, may be produced in treated plants.