Protein Metabolism in Senescing Wheat Leaves 1: Determination of Synthesis and Degradation Rates and Their Effects on Protein Loss

摘要

Wheat leaves (Triticum aestivum L.) at the moment of their maximum expansion were detached and put in darkness. Their protein, RNA and DNA contents, as well as their rates of protein synthesis and degradation, were measured at different times from 0 to 5 days after detachment. Rates of protein synthesis were measured by incorporation into proteins of large amounts of [3H]leucine. Fractional rates of protein degradation were estimated either from the difference between the rates of synthesis and the net protein change or by the disappearance of radioactivity from proteins previously labeled with [3H]leucine or [14C]proline.