Figure 4.

CDL1 Interacts with OST1 in Vitro and in Vivo.

(A) Yeast two-hybrid assay to test the interaction between CDL1 and OST1. CDL1 fused to the DNA binding domain (BD), OST1 fused to the activation domain (AD), BD, and AD constructs were cotransformed into yeast cells according to the indicated combination. Yeast cells were grown on SD or SD-histidine (His) medium with different concentration of 3-amino-1,2,4-triazole (3-AT).

(B) In vitro interaction of CDL1 with OST1. MBP-OST1 pulled down by GST-CDL1 bound beads was analyzed by anti-MBP antibody and anti-GST antibody. An asterisk indicates full length of MBP-OST1 protein.

(C) Both ABA and BR increase CDL1 binding to OST1 in Arabidopsis. Coimmunoprecipitation assay was performed using protein extracts from double transgenic plants coexpressing the indicated constructs. Plants were treated by mock, 0.1 μM BL, 1 μM ABA, or the combination of BL and ABA for 1 h prior to protein extraction.