PhoB also translocates to plant nuclei in leaf and crown cells in response to HK activation with exogenous cytokinin. PhoB also translocates to plant nuclei in leaf and crown cells in response to HK activation with exogenous cytokinin. (A–D) Localization of PhoB‐GFP in leaves. Leaf (A) before and (B) after exogenous cytokinin treatment. (C) Close‐up view of leaf showing punctate PhoB‐GFP. (D) DAPI staining of the same area showing that the punctate compartments are nuclei. (E–H) PhoB‐GFP localization in the Arabidopsis crown, a stem‐like region. Crown (E) before and (F) after cytokinin treatment. (G) Close‐up view of (F) showing punctate GFP localization. (H) DAPI staining of area shown in (G), indicating that punctate GFP compartments are nuclei. Arrowheads point to nuclei. −CK, tissues before cytokinin treatment; +CK same tissue after cytokinin treatment; DAPI, tissues treated with DAPI to stain DNA. Scale bars, 50 μm in (A, B, E, F); scale bars, 10 μm in (C, D, G, H). Mauricio S Antunes et al. Mol Syst Biol 2009;5:270 © as stated in the article, figure or figure legend