Changes in the Composition and Synthesis of Proteins in Cellular Membranes of Echinochloa crus-galli (L.) Beauv. Seeds during the Transition from Dormancy to Germination.

The effect of alcohols which stimulate or have no effect on germination on the composition and synthetic pattern of proteins in the cellular membranes of Echinochloa crus-galli (L.) Beauv. seeds was studied. Imbibition of dry seeds was accompanied by an increase in the synthesis of proteins and by synthesis of new proteins in their intracellular membranes. The transition of the seeds from a dormant to a nondormant state was associated with synthesis of specific proteins and a decrease in content of others in the plasma membrane. The synthesis of a 23 kilodalton protein was strongly increased upon release from dormancy. The changes in the pattern of protein synthesis were not directly associated with the beginning of germination. The results suggest that the plasma membrane constitutes the first site in the seed cells, at which the stimulus from external factors affecting seed dormancy is detected.