Figure 5.

Constitutive expression of hab1^W385A leads to reduced ABA sensitivity. A, Seed germination and seedling establishment of representative Columbia (Col) wild-type, 35S:HAB1, and 35S:hab1^W385A plants in medium lacking or supplemented with ABA. Photographs were taken 7 d after sowing. B, Inhibition of seed germination and seedling establishment by ABA in Columbia wild-type, 35S:HAB1, and 35S:hab1^W385A plants. C, Immunoblot analysis using antibody against HA tag to quantify phosphatase expression in transgenic lines. Ponceau staining from the large subunit of Rubisco is shown as loading control. D, Enhanced water loss measured in detached leaves of 35S:HAB1 and 35S:hab1^W385A plants as compared to Columbia wild type. Values are averages from two independent experiments (n = 10), and sd (not shown) was below 7%. E, The photograph illustrates the severe phenotype observed in 35S:hab1^W385A plants after 60 min of water loss. F, Reduced expression of ABA-inducible genes in 35S:hab1^W385A (line 4) and 35S:HAB1 plants compared with Columbia wild type. Values are expression levels reached in the transgenic lines with respect to wild type (value 1) as determined by reverse transcription-quantitative PCR analysis. Expression of gene markers was analyzed in 10-d-old seedlings treated with 10 μm ABA for 3 h. Values are averages ± sd for two independent experiments (n = 30–40 seedlings per experiment). MS, Murashige and Skoog medium. [See online article for color version of this figure.]