title: Cell fate in the Arabidopsis root epidermis is determined by competition between WEREWOLF and CAPRICE.
abstract: The root hair and nonhair cells in the Arabidopsis (Arabidopsis thaliana) root epidermis are specified by a suite of transcriptional regulators. Two of these are WEREWOLF (WER) and CAPRICE (CPC), which encode MYB transcription factors that are required for promoting the nonhair cell fate and the hair cell fate, respectively. However, the precise function and relationship between these transcriptional regulators have not been fully defined experimentally. Here, we examine these issues by misexpressing the WER gene using the GAL4-upstream activation sequence transactivation system. We find that WER overexpression in the Arabidopsis root tip is sufficient to cause epidermal cells to adopt the nonhair cell fate through direct induction of GLABRA2 (GL2) gene expression. We also show that GLABRA3 (GL3) and ENHANCER OF GLABRA3 (EGL3), two closely related bHLH proteins, are required for the action of the overexpressed WER and that WER interacts with these bHLHs in plant cells. Furthermore, we find that CPC suppresses the WER overexpression phenotype quantitatively. These results show that WER acts together with GL3/EGL3 to induce GL2 expression and that WER and CPC compete with one another to define cell fates in the Arabidopsis root epidermis.
authors.affiliation: Department of Systems Biology, Yonsei University, Seoul 120-749, Korea.
authors.forename: Sang-Kee
authors.initials: SK
authors.lastname: Song
authors.forename: Kook Hui
authors.initials: KH
authors.lastname: Ryu
authors.forename: Yeon Hee
authors.initials: YH
authors.lastname: Kang
authors.forename: Jae Hyo
authors.initials: JH
authors.lastname: Song
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Cho
authors.forename: Sang-Dong
authors.initials: SD
authors.lastname: Yoo
authors.forename: John
authors.initials: J
authors.lastname: Schiefelbein
authors.forename: Myeong Min
authors.initials: MM
authors.lastname: Lee
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D019070:Cell Lineage; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D059828:Plant Cells / Q000378:metabolism; D019441:Plant Epidermis / Q000166:cytology* / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D020598:Proto-Oncogene Proteins c-myb / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C511989:CPC protein, Arabidopsis; D004268:DNA-Binding Proteins; D020598:Proto-Oncogene Proteins c-myb; C402111:WER protein, Arabidopsis