Figure 8: BZR1 represses the expression of TPL and TPRs.
From: TOPLESS mediates brassinosteroid-induced transcriptional repression through interaction with BZR1
(a) ChIP-Seq analyses shows BZR1 binding on the promoters of TPL and TPRs. Arrows indicate the direction of transcription. (b) ChIP assays confirm that BZR1 binds to promoters of TPL and TPRs. Transgenic plants expressing bzr1-1D-CFP from the native BZR1 promoter were used for the ChIP assays. BZR1-bound DNA was immunoprecipitated using anti-GFP antibody and analysed by qPCR. BZR1 DNA binding was calculated as the ratio between bzr1-1D-CFP and wild-type samples, normalized to that of PP2A. (c) The expression levels of TPL and TPR3 are reduced by BR treatment. Seedlings grown on the medium containing 2 μM PPZ medium for 7 days were treated with mock (M) or 100 nM BL for 4 h. (d) TPR3 repression by BZR1 requires TPL/TPR activity. Total RNA were extracted from etiolated seedlings grown on the medium containing 2 μM PPZ. The relative gene expression levels were determined by qRT–PCR. Numbers indicate the ratios of expression levels (bzr1-1D/Col-0 or bzr1-1D;tpl;tpr1;tpr4/tpl;tpr1;tpr4). The error bars in b–d indicate the s.d. (n=3). **P<0.01 and *P<0.05 by Student’s t-test.
