The formation of the root epidermis of Arabidopsis provides a simple and elegant model for the analysis of cell patterning. A novel gene, WEREWOLF (WER), is described here that is required for position-dependent patterning of the epidermal cell types. The WER gene encodes a MYB-type protein and is preferentially expressed within cells destined to adopt the non-hair fate. Furthermore, WER is shown to regulate the position-dependent expression of the GLABRA2 homeobox gene, to interact with a bHLH protein, and to act in opposition to the CAPRICE MYB. These results suggest a simple model to explain the specification of the two root epidermal cell types, and they provide insight into the molecular mechanisms used to control cell patterning.
Bibliographical noteFunding Information:
We thank Julia Fuzak and Chen-Yi Hung for technical assistance, Philip Benfey's laboratory for assistance with in situ hybridizations, John Larkin for advice on trichome analysis, and Hailing Jin, Ruth Meissner, and Cathie Martin for helpful discussions and MYB clones. We acknowledge the Arabidopsis Biological Resource Center (Columbus, OH) for providing IGF BAC filter sets and clones, Xuejun Hua for the p5cr marker clone, Alan Lloyd for the R cDNA clone, and James Carrington for the pRTL2-GUS clone. We also thank Liam Dolan, Yan Lin, Alan Lloyd, David Marks, Kiyotaka Okada, Ben Scheres, and Amanda Walker for helpful discussions. This work was supported by a KOSEF postdoctoral fellowship (M. M. L.) and by a grant from the National Science Foundation (IBN-9724149).
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)