CHARACTERIZATION OF THE 32,000 DALTON MEMBRANE PROTEIN—I. EARLY SYNTHESIS DURING PHOTOINDUCED PLASTID DEVELOPMENT OF SPIRODELA

The kinetics of ³⁵S methionine incorporation into soluble and membrane proteins during the transition from steady state dark growth to greening was studied in Spirodela. A sharp increase in the rate of incorporation occurred at 3 h, which was several h before major increases in chlorophyll were apparent. Part of this enhanced incorporation was due to enhanced synthesis of a 32 ,000 dalton membrane protein. This synthesis was paralleled by a temporal increase in in uitro template capacity for this protein and an increase in 0.5 × 10⁶ dalton plastid messenger RNA.