Figure 5: ABI1 degradation is promoted by ABA or ABA receptors in plants, and delayed by ABI1-1 dominant mutation.

(a) ABA promotes ABI1 degradation. The 7-day-old wild type seedlings were treated with 100 μM CHX or 100 μM CHX plus 50 μM ABA for different times. At each time point, proteins were extracted and used for immunoblotting analysis. ACTIN was used as a loading control. (b) Quantitative analysis of the signal intensity in a. The abundance of ABI1 at the 0 h (CHX, CHX+ABA) was set to 1 as a reference for calculating relative abundance of various time point. Error bars are means±s.e.m. (n=3 independent experiments). (c) ABI1 protein is more stabilized in pyr1 pyl1 pyl2 pyl4 quadruple mutant than in the wild type. The total extracted proteins were extracted from 7-day-old seedlings treated with 100 μM CHX for different times and used for immunoblotting analysis with anti-ABI1 antibody. ACTIN was used as a loading control. (d) Quantitative analysis of the signal intensity in e. The abundance of ABI1 at the Col 0 h was set to 1 as a reference for calculating relative abundance of various time point. Error bars are means±s.e.m. (n=3 independent experiments). (e) ABI1 protein is more stable in abi1-1 than in the wild type. The total extracted proteins from the 7-day-old wild type or abi1-1 (Col) seedlings treated with 100 μM CHX for different times were used for immunoblotting analysis with anti-ABI1 antibody. ACTIN was used as a loading control. (f) Quantitative analysis of the signal intensity in g. The abundance of ABI1 at the Col 0 h was set to 1 as a reference for calculating relative abundance of various time point. Error bars are means±s.e.m. (n=3 independent experiments).