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Article

  • The EMBO Journal (2004) 23, 3290 - 3302
  • doi:10.1038/sj.emboj.7600337

Published online: 29 July 2004

The response regulator 2 mediates ethylene signalling and hormone signal integration in Arabidopsis

Claudia Hass1, Jens Lohrmann2, Verónica Albrecht3,4, Uta Sweere1,2, Florian Hummel2, Sang Dong Yoo5, Ildoo Hwang6, Tong Zhu7, Eberhard Schäfer2, Jörg Kudla3,4 and Klaus Harter1

  1. Botanisches Institut, Universität zu Köln, Köln, Germany
  2. Institut für Biologie II, Universität Freiburg, Freiburg, Germany
  3. Institut für Botanik und Botanischer Garten, Universität Münster, Münster, Germany
  4. Molekulare Botanik, Universität Ulm, Ulm, Germany
  5. Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
  6. Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, Korea
  7. Syngenta Biotechnology Inc., Research Triangle Park, NC, USA

Correspondence to:

Jörg Kudla, Institut für Botanik und Botanischer Garten, Universität Münster, Schlossgarten 3, 48149 Münster, Germany. Tel.: +49 251 83 24813; Fax: +49 251 83 23823; E-mail: jkudla@uni-muenster.de

Klaus Harter, Botanisches Institut, Universität zu Köln, Gyrhofstr. 15, 50931 Köln, Germany. Tel.: +49 221 470 6897; Fax: +49 221 470 7765; E-mail: klaus.harter@uni-koeln.de

Received 8 December 2003; Accepted 29 June 2004

Hormones are important regulators of plant growth and development. In Arabidopsis, perception of the phytohormones ethylene and cytokinin is accomplished by a family of sensor histidine kinases including ethylene-resistant (ETR) 1 and cytokinin-response (CRE) 1. We identified the Arabidopsis response regulator 2 (ARR2) as a signalling component functioning downstream of ETR1 in ethylene signal transduction. Analyses of loss-of-function and ARR2-overexpressing lines as well as functional assays in protoplasts indicate an important role of ARR2 in mediating ethylene responses. Additional investigations indicate that an ETR1-initiated phosphorelay regulates the transcription factor activity of ARR2. This mechanism may create a novel signal transfer from endoplasmic reticulum-associated ETR1 to the nucleus for the regulation of ethylene-response genes. Furthermore, global expression profiling revealed a complex ARR2-involving two-component network that interferes with a multitude of different signalling pathways and thereby contributes to the highly integrated signal processing machinery in higher plants.

  • Keywords:

    • expression profiling,
    • phosphorelay,
    • phytohormone signalling,
    • response regulator,
    • two-component system