The NAC domain transcription factors FEZ and SOMBRERO control the orientation of cell division plane in Arabidopsis root stem cells.
Because plant cells do not migrate, cell division planes are crucial determinants of plant cellular architecture. In Arabidopsis roots, stringent control of cell divisions leads to a virtually invariant division pattern, including those that create new tissue layers. However, the mechanisms that control oriented cell divisions are hitherto poorly understood. Here, we reveal one such mechanism in which FEZ and SOMBRERO (SMB), two plant-specific NAC-domain transcription factors, control the delicately tuned reorientation and timing of cell division in a subset of stem cells. FEZ is expressed in root cap stem cells, where it promotes periclinal, root cap-forming cell divisions. In contrast, SMB negatively regulates FEZ activity, repressing stem cell-like divisions in the root cap daughter cells. FEZ becomes expressed in predivision stem cells, induces oriented cell division, and activates expression of its negative regulator, SMB, thus generating a feedback loop for controlled switches in cell division plane.
Willemsen
Viola
V
Department of Molecular Genetics, University of Utrecht, Utrecht, The Netherlands.
Bauch
Marion
M
Bennett
Tom
T
Campilho
Ana
A
Wolkenfelt
Harald
H
Xu
Jian
J
Haseloff
Jim
J
Scheres
Ben
B
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D002455:Cell Division; D003001:Cloning, Molecular; D004742:Enhancer Elements, Genetic; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D008954:Models, Biological; D008969:Molecular Sequence Data; D016296:Mutagenesis; D018517:Plant Roots / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*
D029681:Arabidopsis Proteins; C534300:FEZ protein, Arabidopsis; C534299:SOMBRERO protein, Arabidopsis; D014157:Transcription Factors