Gamma-aminobutyric acid (GABA), a nonproteinous amino acid with some benefits on human health, is synthesized by GABA-shunt and the polyamine degradation pathway in plants. The regulation of Ca2þ and aminoguanidine on GABA accumulation in germinating soybean (Glycine max L.) under hypoxia-NaCl stress was investigated in this study. Exogenous Ca2þ increased GABA content significantly by enhan…