Figure 2.

ABA Sensitivity of 35S-ABF3 and 35S-ABF4 Plants.

(A) Growth of transgenic plants on Murashige and Skoog (1962) medium (MS) containing 0.5 μM ABA. Seed were germinated and grown for 12 days.

(B) Growth of transgenic plants on MS medium containing 0.25 μM ABA. Seed were germinated on the medium for 3 days, and representative plants are shown.

(C) ABA dose response of germination. Seed, 6 months old after harvest and prechilled at 4°C for 4 days, were germinated on media containing various concentrations of ABA, and seedlings with fully emerged radicles were counted after 3 days. Experiments were performed in triplicate (n = 50 each), and the bars show standard errors.

(D) ABA dose response of root growth. Seed were germinated for 4 days on ABA-free medium, and the seedlings (n = 6) were transferred to media containing various concentrations of ABA. Root elongation was measured 5 days after the transfer. The experiments were performed more than four times, sometimes using different transgenic lines, and the results were consistent. The small bars represent standard errors. Transgenic lines A319 (ABF3) and A405 (ABF4) were used.