Figure 2.

Effect of external pH on hormonal regulation of carboxypeptidase III (2437 cDNA) and thiol protease (2529 cDNA) transcript accumulation. Wheat de-embryonated half grains were incubated for 2 d on filter paper soaked with 20 mm sodium acetate, pH 5.0; 20 mm sodium phosphate, pH 7.0 (I); or 20 mm Mops-NaOH, pH 7.0 (II), supplemented with 10 mm CaCl₂. Hormone treatments were as follows: lanes 1, no hormone; lanes 2, 5 μm GA₃; lanes 3, 25 μm ABA; lanes 4, 5 μm GA₃ plus 25 μm ABA. RNA samples (10 μg) were electrophoresed, blotted onto Hybond-N filters, and hybridized with ³²P-labeled 2529 cDNA (thiol protease) or 2437 cDNA (carboxypeptidase III). Even loading was checked by rehybridizing filters with ³²P-labeled 18S rRNA.