Changing Patterns of Regulation as Root Cells of Zea mays Mature ) )

Abstract

Summary Additions of glucose to root tip (5 mm) sections of Zea mays result in an enhanced incorporation of acetate carbon into the neutral and basic amino acid fraction, and into protein and a reduced incorporation of acetate carbon into asparagine. Similar experiments with mature root sections (20–25mm from the tip) show that the glucose effect on protein synthesis and asparagine formation have been lost. When proline is used as the radioactive tracer the incorporation of carbon into protein is enhanced and the oxidation of proline is inhibited by the addition of glucose to root tip sections. In mature sections there is no effect of glucose on protein synthesis. It does, however, still inhibit the oxidation of proline.