The reconstruction of the proteolytic system responsible for the profound hydrolysis of the main storage protein of buckwheat seeds, 13S globulin, has been carried out in vitro. It was found that subsequent action of a metalloproteinase from dry buckwheat seeds and cysteine proteinase and carboxypeptidase from growing seedlings led to a profound hydrolysis of the storage protein. The 13S globulin that was not hydrolyzed with metalloproteinase was not degraded by the proteolytic enzymes of growing seedlings. A scheme is proposed, which describes the functioning of the proteolytic system hydrolyzing the storage protein in growing buckwheat seedlings in vivo.