3.4. Effects of GA3 in soaking solution
GABA contents were significantly increased (P < 0.01) by adding
GA3 in the soaking water, and there was a significant difference
between the two cultivars (Fig. 5). With GA3 in soaking
water, GABA content in indica rice showed a linear increase
until 42 h after germination (Fig. 5A), while that in japonica
rice increased until 24 h, but dropped between 24 and 36 h of
germination (Fig. 5B). In both cultivars, an intermediate GA3
concentration of 0.25 mg L−1 had the greatest positive effect
on GABA content in GBR. The optimal GA3 treatment
(soaking at 0.25 mg L−1) resulted in high levels of GABA at 6 h