Physiological change and the regulation of γ-aminobutyric acid accumulation in germinated soybean under inhibitors of calcium channel treatment

The effect of membrane calcium channel inhibitor( La Cl3) and endometrium calcium channel inhibitor( Heparin) on the main physiological metabolism and γ- aminobutyric acid( GABA) accumulation in soybeans during germination under Na Cl stress were investigated. Under Na Cl combining La Cl3 treatment,the growth of germinating soybeans was further suppressed,the sprout length decreased significantly,while no significant change was observed under heparin treatment. However,the respiratory rate both increased significantly under La Cl3 and heparin treatment.Compared with Na Cl treatment,rate- limiting enzyme activities of GABA metabolism in cotyledon decreased significantly under Na Cl plus La Cl3 or heparin treatment.Under La Cl3 treatment,GABA content was 50% and 79% of the Na Cl treatment in cotyledon and embryo,respectively.However,under heparin treatment,GABA content in cotyledon and embryo was 70% and 66% of the Na Cl treatment,respectively.This result indicates that the inhibit effect of endogenous calcium stores on GABA content was smaller than membrane calcium channel.