Abstract
Storage proteins in cotyledon of legume plant are degraded by proteases expressed during seed germination and are mobilized to the embryonic axis for its growth. In aleuron layers of rice or barley, expression of proteases is induced by gibberellin (GA) and its induction is antagonized by abscisic acid (ABA). We examined whether GA and ABA regulate expression of the proteases in cotyledons of germinated bean seeds with RNA blot analysis of the genes for 7 cysteine proteases, EP-C1, CP1, CP2, CP3, CP4, LLP1 and LLP2. Our result indicated that expression of the 6 genes except of CP4 was repressed by GA biosynthesis inhibitors or ABA, suggesting that GA and ABA regulates mainly the expression of the proteases in germinated cotyledons. We will report effects of inhibitors of ethylene action on the expression of the genes, because ethylene is known to be involved in regulation ofgermination.
