The enzymatic incorporation of (32)P into ATP and other organic compounds by sieve-tube sap of Macrocystis integrifolia Bory

Abstract

The stipe of Macrocystis integrifolia Bory, when cut near its base, released sieve-tube sap at a rate of 1.55 to 2.1 ml h(-1). This sap contained a high amount of ATP. When the sap was incubated with (32)PO4 (3-) the radioactivity was rapidly incorporated into a number of organic compounds, of which ATP was the most heavily labeled. This incorporation was due to enzymatic activity present in the sieve tube sap. The physiological significance of these results in translocation of assimilates in the brown algae is discussed.