Protrusion of the radicle is the first physical evidence of seed germination. our previous analysis of the fine structure of radicles from dry seeds revealed an abundance of protein and lipid reserves in the cortical parenchyma of hypocotyls and radicles. In this study we tested the hypothesis that utilization of stored protein is involved in radicle protrusion. Data for elongation and protein content (total and SDS PAGE) of intact and excised axes(hypocotyl and radicle), hypocotyls and radicles from cotton (Gossypium hirsutum L. var M-8) seeds were analyzed and compared after 24 h imbibition in vitro 30 C. Results indicate storage proteins in radicles are utilized during 24 h imbibition in parallel with radicle elongation. The extent of excised radicle elongation is similar or slightly less than radicles of intact seeds. This difference in radicle length changed remarkably when excised axes were used. The change in protein content and dry weight were greatly reduced for radicles after 24 hr in vitro germination. In fact, the elongation of radicles was 50% greater than for radicles of intact seeds or excised organs. These results suggest a role of hypocotyls in radicle elongation which is not readily observed in intact seeds. These differences were further reflected in changes in total protein and polypeptide patterns of dry versus imbibed hypocotyl and radicle tissues, particularly in major storage proteins.