Fig. 4.

ABA-binding assay of the recombinant CHLH protein. a, b Coomassie Brilliant Blue staining of the recombinant His-tagged CHLH, PYR1, and ABI1 proteins used for the ABA-binding assay. Asterisks indicate degradation products of CHLH. The sizes of the molecular weight markers are shown on the left. c Determination of ABA-binding activity of the recombinant proteins by the filter method. Two micromolar recombinant protein and 50 nM ³H-labeled ABA were incubated in the absence (black) or presence of 1,000-fold unlabeled ABA (white) for 1 h at 25°C. Data represent the mean of three independent experiments with SD