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Ectopic Expression of EFFECTOR OF TRANSCRIPTION Perturbs Gibberellin-Mediated Plant Developmental Processes

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Abstract

The plant hormone gibberellin (GA) is known to modulate various aspects of plant cell differentiation and development. The current model of GA-mediated regulation is based on a de-repressible system and includes specific protein modification and degradation. HRT, a zinc finger protein from barley has been shown to have GA-dependent transcriptional repressing activity on the seed-specific α-amylase promoter [Raventos, D., Skriver, K., Schlein, M., Karnahl, K., Rogers, S.W., Rogers, J.C. and Mundy, J. 1998. J.␣Biol. Chem. 273: 23313–23320]. Here we report the characterization of a dicot homologue from Brassica napus (BnET) and provide evidence for its role in GA response modulation suggesting that this could be a conserved feature of this gene family. When BnET is ectopically expressed in either Arabidopsis or tobacco the phenotypes include dwarfism due to shorter internodes and late flowering, reduced germination rate, increased anthocyanin content and reduced xylem lignification as a marker for terminal cell differentiation. Transient expression in protoplasts supports the notion that this most likely is due to a transcriptional repression of GA controlled genes. Finally, histological analysis showed that in contrast to other GA deficient mutants the shorter internodes were due to fewer but not smaller cells, suggesting a function of BnET in GA-mediated cell division control.

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  1. M. Ellerström & W. Reidt

    Present address: Botanik 2, University Karlsruhe, Kaiserstrasse 12, 76131, Karlsruhe, Germany

Authors and Affiliations

  1. Botanical Institute, Gothenburg University, Box 461, SE- 405 30, Gothenburg, Sweden

    M. Ellerström

  2. Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Corrensstrasse 3, 06466, Gatersleben, Germany

    W. Reidt, R. Ivanov, J. Tiedemann, M. Melzer, A. Tewes, H.-P. Mock & H. Bäumlein

  3. Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 87, Umeå, Sweden

    T. Moritz

  4. Department of Medical Biochemistry and Microbiology, Uppsala University, Box 582, SE-751 23, Uppsala, Sweden

    F. Sitbon & L. Rask

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M. Ellerström and W. Reidt have contributed equally to this study and should both be considered as first authors.

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Ellerström, M., Reidt, W., Ivanov, R. et al. Ectopic Expression of EFFECTOR OF TRANSCRIPTION Perturbs Gibberellin-Mediated Plant Developmental Processes. Plant Mol Biol 59, 663–681 (2005). https://doi.org/10.1007/s11103-005-0669-9

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