Abstract:

After 4-day germination, the germination percentage, sprout length and respiratory rate of the soybean cultivarYH-NJ were higher than those of all other cultivars tested. The increment of soluble protein, free amino acids and proteaseactivity in YH-NJ sprouts were higher than those of the other cultivars. The content of (GABA) was increased and its levelin YH-NJ sprouts was the highest. Thus, the cultivar YH-NJ was selected for GABA accumulation in further experiments.Using orthogonal design method, the optimal culture conditions for GABA accumulation in 4-day germinated YH-NJ sprouts weredetermined as germination in a culture solution at pH 5.0 for another 48 h under hypoxia stress at 30 ℃. Under these conditions,the content of GABA was 1.97 mg/g DW, which was 1.56 times higher than the control.

Key words: soybean, germination, γ-aminobutyric acid (GABA), accumulation, cultivar selection, condition optimization, hypoxia stress