Figure 5.

Saturation curves (●) of the ABA-binding activities to the crude (a) and purified ABA-binding proteins (b). ³H-(±)ABA at a gradient of concentrations was added to the incubation medium. The free ³H-ABA concentrations were adjusted to ³H-(+)ABA concentrations (one-half of the ³H-[±]ABA concentrations). As indicated in both of the figures above, the nonspecific binding (○) was determined with 1,000-fold molar excess of cold ABA and was lower than 10%. Points are means ± sd of five determinations.