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WUSCHEL controls meristem function by direct regulation of cytokinin-inducible response regulators


Plants continuously maintain pools of totipotent stem cells in their apical meristems from which elaborate root and shoot systems are produced. In Arabidopsis thaliana, stem cell fate in the shoot apical meristem is controlled by a regulatory network that includes the CLAVATA (CLV) ligand–receptor system and the homeodomain protein WUSCHEL (WUS)1,2. Phytohormones such as auxin and cytokinin are also important for meristem regulation3. Here we show a mechanistic link between the CLV/WUS network and hormonal control. WUS, a positive regulator of stem cells, directly represses the transcription of several two-component ARABIDOPSIS RESPONSE REGULATOR genes (ARR5, ARR6, ARR7 and ARR15), which act in the negative-feedback loop of cytokinin signalling4,5. These data indicate that ARR genes might negatively influence meristem size and that their repression by WUS might be necessary for proper meristem function. Consistent with this hypothesis is our observation that a mutant ARR7 allele, which mimics the active, phosphorylated form, causes the formation of aberrant shoot apical meristems. Conversely, a loss-of-function mutation in a maize ARR homologue was recently shown to cause enlarged meristems6.

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Figure 1: Expression profiles of ARR5, ARR6, ARR7 and ARR15.
Figure 2: Expression patterns of ARR7 and WUS in response to meristematic signals.
Figure 3: Direct interaction of WUS with regulatory sequences of ARR7.
Figure 4: Phenotypes of type-A ARR mutant plants.


  1. Schoof, H. et al. The stem cell population of Arabidopsis shoot meristems in maintained by a regulatory loop between the CLAVATA and WUSCHEL genes. Cell 100, 635–644 (2000)

    CAS  Article  Google Scholar 

  2. Brand, U., Fletcher, J. C., Hobe, M., Meyerowitz, E. M. & Simon, R. Dependence of stem cell fate in Arabidopsis on a feedback loop regulated by CLV3 activity. Science 289, 617–619 (2000)

    ADS  CAS  Article  Google Scholar 

  3. Leyser, O. Regulation of shoot branching by auxin. Trends Plant Sci. 8, 541–545 (2003)

    CAS  Article  Google Scholar 

  4. Kiba, T. et al. The type-A response regulator, ARR15, acts as a negative regulator in the cytokinin-mediated signal transduction in Arabidopsis thaliana. Plant Cell Physiol. 44, 868–874 (2003)

    CAS  Article  Google Scholar 

  5. To, J. P. et al. Type-A Arabidopsis response regulators are partially redundant negative regulators of cytokinin signalling. Plant Cell 16, 658–671 (2004)

    CAS  Article  Google Scholar 

  6. Giulini, A., Wang, J. & Jackson, D. Control of phyllotaxy by the cytokinin-inducible response regulator homologue ABPHYL1. Nature 430, 1031–1034 (2004)

    ADS  CAS  Article  Google Scholar 

  7. Laux, T., Mayer, K. F., Berger, J. & Jurgens, G. The WUSCHEL gene is required for shoot and floral meristem integrity in Arabidopsis. Development 122, 87–96 (1996)

    CAS  PubMed  Google Scholar 

  8. Long, J. A., Moan, E. I., Medford, J. I. & Barton, M. K. A member of the KNOTTED class of homeodomain proteins encoded by the STM gene Arabidopsis. Nature 379, 66–69 (1996)

    ADS  CAS  Article  Google Scholar 

  9. Clark, S. E., Running, M. P. & Meyerowitz, E. M. CLAVATA1, a regulator of meristem and flower development in Arabidopsis. Development 119, 397–418 (1993)

    CAS  PubMed  Google Scholar 

  10. Clark, S. E., Running, M. P. & Meyerowitz, E. M. CLAVATA3 is a specific regulator of shoot and floral meristem development affecting the same processes a CLAVATA1. Development 121, 2057–2067 (1995)

    CAS  Google Scholar 

  11. Kayes, J. M. & Clark, S. E. CLAVATA2, a regulator of meristem and organ development in Arabidopsis. Development 125, 3843–3851 (1998)

    CAS  PubMed  Google Scholar 

  12. Mayer, K. F. X. et al. Role of WUSCHEL in regulating stem cell fate in the Arabidopsis shoot meristem. Cell 95, 805–815 (1998)

    CAS  Article  Google Scholar 

  13. Fletcher, J. C., Brand, U., Running, M. P., Simon, R. & Meyerowitz, E. M. Signaling of cell fate decisions by CLAVATA3 in Arabidopsis shoot meristems. Science 283, 1911–1914 (1999)

    ADS  CAS  Article  Google Scholar 

  14. Rojo, E., Sharma, V. K., Kovaleva, V., Raikhel, N. V. & Fletcher, J. C. CLV3 is localized to the extracellular space, where it activates the Arabidopsis CLAVATA stem cell signalling pathway. Plant Cell 14, 969–977 (2002)

    CAS  Article  Google Scholar 

  15. Clark, S. E., Williams, R. W. & Meyerowitz, E. M. The CLAVATA1 gene encodes a putative receptor kinase that controls shoot and floral meristem size in Arabidopsis. Cell 89, 575–585 (1997)

    CAS  Article  Google Scholar 

  16. Jeong, S., Trotochaud, A. E. & Clark, S. E. The Arabidopsis CLAVATA2 gene encodes a receptor-like protein required for the stability of the CLAVATA1 receptor-like kinase. Plant Cell 11, 1925–1934 (1999)

    CAS  Article  Google Scholar 

  17. Lohmann, J. U. et al. A molecular link between stem cell regulation and floral patterning in Arabidopsis. Cell 105, 793–803 (2001)

    CAS  Article  Google Scholar 

  18. Roslan, H. A. et al. Characterization of the ethanol-inducible alc gene-expression system in Arabidopsis thaliana. Plant J. 28, 225–235 (2001)

    CAS  Article  Google Scholar 

  19. Lenhard, M., Bohnert, A., Jürgens, G. & Laux, T. Termination of stem cell maintenance in Arabidopsis floral meristems by interactions between WUSCHEL and AGAMOUS. Cell 105, 805–814 (2001)

    CAS  Article  Google Scholar 

  20. Lemon, W. J., Liyanarachchi, S. & You, M. A high performance test of differential gene expression for oligonucleotide arrays. Genome Biol. 4, R67 (2003)

    Article  Google Scholar 

  21. D'Agostino, I. B., Deruere, J. & Kieber, J. J. Characterization of the response of the Arabidopsis response regulator gene family to cytokinin. Plant Physiol. 124, 1706–1717 (2000)

    CAS  Article  Google Scholar 

  22. D'Agostino, I. B. & Kieber, J. J. Phosphorelay signal transduction: the emerging family of plant response regulators. Trends Biochem. Sci. 24, 452–456 (1999)

    CAS  Article  Google Scholar 

  23. Skoog, F. & Miller, C. O. Chemical regulation of growth and organ formation in plant tissues cultured in vitro. Symp. Soc. Exp. Biol. 54, 118–130 (1957)

    Google Scholar 

  24. Hwang, I. & Sheen, J. Two-component circuitry in Arabidopsis cytokinin signal transduction. Nature 413, 383–389 (2001)

    ADS  CAS  Article  Google Scholar 

  25. Schmid, M. et al. A gene expression map of Arabidopsis thaliana development. Nature Genet. 37, 501–506 (2005)

    MathSciNet  CAS  Article  Google Scholar 

  26. Brand, U., Grunewald, M., Hobe, M. & Simon, R. Regulation of CLV3 expression by two homeobox genes in Arabidopsis. Plant Physiol. 129, 565–575 (2002)

    CAS  Article  Google Scholar 

  27. Lenhard, M., Jurgens, G. & Laux, T. The WUSCHEL and SHOOTMERISTEMLESS genes fulfil complementary roles in Arabidopsis shoot meristem regulation. Development 129, 3195–3206 (2002)

    CAS  PubMed  Google Scholar 

  28. Hass, C. et al. The response regulator 2 mediates ethylene signalling and hormone signal integration in Arabidopsis. EMBO J. 23, 3290–3302 (2004)

    CAS  Article  Google Scholar 

  29. Schmid, M. et al. Dissection of floral induction pathways using global expression analysis. Development 130, 6001–6012 (2003)

    CAS  Article  Google Scholar 

  30. Wu, Z., Irizarry, R. A., Gentleman, R., Murillo, F. M. & Spencer, F. A. A model based background adjustment for oligonucleotide expression arrays. Working Paper 1 (Dept of Biostatistics Working Papers, Johns Hopkins Univ., Baltimore, Maryland, 2004).

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We thank A. Greenland for providing the AlcA system, J. Palatnik for sharing unpublished results, R. Schwab for establishing the in situ protocol, R. Chen for preparing the WUS antiserum, K. Harter and D. Weigel for discussion, and K. Bomblies, I. Lohmann, M. Schmid, J. Palatnik and D. Weigel for reading the manuscript critically. This work was supported by a Career Development Award of the International Human Frontier Science Program (HFSP) Organization (J.U.L.), a Ph.D. fellowship of the Cusanuswerk (W.B.), grants from the NSF and the NIH (J.J.K.) and the Max Planck Society (J.U.L).Author Contributions A.L. performed in situ hybridizations and qRT–PCRs, constructed reporter genes, the mutated alleles of ARR7 and performed electron microscopy; J.P.C.T. and J.J.K. generated and analysed the arr double and septuple mutants; W.B. performed the ChIP experiments; S.S. generated constructs and transgenic lines of ARR genes; A.K. generated AlcA::CLV3 plants; M.D. performed qRT–PCRs; and J.U.L. carried out the microarray experiment and analysis, performed gel-shifts and wrote the paper. All authors discussed the results and commented on the manuscript.

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Correspondence to Jan U. Lohmann.

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Microarray data have been deposited at ArrayExpress ( under accession number E-MEXP-432. Reprints and permissions information is available at The authors declare no competing financial interests.

Supplementary information

Supplementary Figure 1

Expression patterns of ARR7 RNA. (PDF 105 kb)

Supplementary Figure 2

Activity of ARR5, ARR6, ARR7 and ARR15 GUS reporter genes. (PDF 65 kb)

Supplementary Figure 3

Direct interaction of WUS with regulatory sequences of ARR7. (PDF 81 kb)

Supplementary Table 1

Genes responsive to WUS induction. (PDF 57 kb)

Supplementary Table 2

Oligonucleotides used in Leibfried et al. (PDF 60 kb)

Supplementary Methods

Additional information on mutants and ChIP. (PDF 68 kb)

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Leibfried, A., To, J., Busch, W. et al. WUSCHEL controls meristem function by direct regulation of cytokinin-inducible response regulators. Nature 438, 1172–1175 (2005).

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