Fig. 1.

HERK1, THE1, and FER are related receptor-like kinases induced by BRs. (A) Expression of HERK1, THE1, and FER is induced by BL treatment in 10-day-old seedlings and 4-week-old adult plants. Triplicate biological samples were used to prepare RNA for quantitative RT PCR. The relative expression levels compared with UBQ5 gene were used to determine the BL-induction levels of each gene. The averages and standard deviations from 3 biological repeats are shown. (B) HERK1, THE1, and FER are up-regulated in bes1-D and down-regulated in bri1. Ten-day-old seedlings were used to prepare RNA for qRT-PCR as described in A. (C–E) HERK1 cellular localization: A HERK1-GFP (C) or BES1-D-GFP (D) construct was introduced into protoplasts or transgenic plants (E). HERK1 is mostly localized at the plasma membrane (C and E), whereas BES1-D is primarily in the nucleus (D). (F) HERK1 displayed kinase activity. Recombinant proteins fused with MBP representing the WT HERK1 kinase domain (WT), and a mutant version with disrupted kinase activity (mutant), were used in kinase assay. Autophosphorylation was detected by phosphorimaging, and the proteins were detected by SYPRO RUBY staining. (G–I) Expression patterns of HERK1, THE1, and FER in 10-day-old seedlings (G and H) or 3-week-old adult leaves (I) as revealed by GUS reporter gene. (Scale bars: C and D, 10 μm; G and H, 2.5 mm; I, 10 mm.)