Fig. 2.

BIK1 negatively regulates BR signaling. (A) BES1 phosphorylation in WT and bik1 mutant plants. The phosphorylated (pBES1) and dephosphorylated BES1 proteins were detected with an α-BES1 antibody (Upper). Equal loading was ensured by total protein quantification before loading and by Coomassie brilliant blue staining (CBS) of the membrane (Lower). The band intensity was quantified by ImageJ software and labeled under the gel. (B) Expression of BR responsive genes with qRT-PCR analysis. Ten-day-old seedlings were treated with 2 μM BL or H₂O for 2 h. The expression of BR6OX, CPD, or DWF4 was normalized to the expression of UBQ10. The data are shown as mean ± SE from three independent biology repeats. Asterisk indicates a significant difference with P < 0.05 compared with data from WT seedlings. The above experiments were repeated three times with similar results.