Figure 7: BR repression of gene expression requires HDA activity.
From: TOPLESS mediates brassinosteroid-induced transcriptional repression through interaction with BZR1
(a) BZR1 associates with both TPL and HDA19 in vivo. Arabidopsis mesophyll protoplasts were transfected with bzr1-1D-GFP together with TPL-Myc and HDA19-Myc, and the extracted proteins were immunoprecipitated by anti-GFP antibody. Gel blots were probed with anti-Myc or anti-GFP antibody. (b) HDA inhibitor, trichostatin A (TSA) diminishes BR repressive effect on the expression of DWF4 and CPD. Total RNA was extracted from 2-week-old plants treated with 100 nM BL±10 μM TSA for 1 h. The relative gene expression levels were determined by qRT–PCR. Error bars indicate the s.d. (n=3). Numbers indicate the ratios of expression levels (BL/M or TSA+BL/TSA). (c) TSA treatment inhibits BZR1 promotion of hypocotyl elongation. Seedlings were grown on the medium containing 2 μM PPZ with or without 1 μM TSA in the dark. The error bars in the lower graph indicate the s.d. (n=10 plants). Scale bar, 5 mm.
