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Schriftzug Angewandte Genetik Collage von Motiven der Angewandten Genetik

Dahlem Research School

Member of Dahlem Centre of Plant Sciences (DCPS)

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Research group Werner

Research interest

Plant development and growth are multifactorial processes regulated by a large number of endogenous signals and environmental cues. Besides other functions, the plant hormone cytokinin is a key morphogenic factor controlling cell division and thus formation and growth rate of organs during the plant life cycle. The question, which plant developmental programs are under cytokinin control and which molecular mechanisms underlie cytokinin action in these processes, is in the focus of our research.

Scheme of cytokinin metabolism
Schematic model of cytokinin metabolism. Biosynthesis of cytokinins is initiated by adenosine phosphate-isopentenyltransferases (IPTs) to form iP-nucleotides which can be converted to the corresponding tZ-nucleotides by cytochrome P450 monooxygenases (CYP735As). Cytokinin nucleotides can be directly converted to active free bases by cytokinin nucleoside 5'-monophosphate phosphoribohydrolases (LOGs). Biologically active cytokinins are highlighted in grey, and can be inactivated by cytokinin oxidases/dehydrogenases (CKXs) and by conjugation to sugar moieties through glycosyltransferases (UGTs).

We are interested in metabolic regulation of cytokinin concentration in plant cell with a specific focus on catabolic pathway mediated by cytokinin oxidases/dehydrogenases (CKX) enzymes. We also aim to understand underlying mechanisms of cytokinin activity and to identify new genetic factors, which mediate or interact with the hormone activity. To this end, we carried out a suppressor mutagenesis of cytokinin deficient Arabidopsis plants - plants overexpressing CKX gene and displaying complex phenotypic changes such as dwarfed shoot - and screened for a phenotypic reversion. We isolated several recessive and dominant second-site suppressor alleles termed rock (repressor of cytokinin deficiency), which we currently map and functionally characterise.

Examples of phenotypic reversions in different second-site <i>rock</i> suppressor lines
Examples of phenotypic reversions in different second-site rock suppressor lines.


Junior-Prof. Dr. Tomáš Werner
Group leader
Phone office: +49-(0)30-838-56796
Fax: +49-(0)30-838-54345
e-mail: tower{at}

Felicitas Wronski
Lab technician
Phone office: +49-(0)30-838-56792
Phone lab: +49-(0)30-838-56874
e-mail: f.wronski{at}

Dr. Michael Niemann
Research assistant
Phone office: +49-(0)30-838-56792
Phone lab: +49-(0)30-838-56874
e-mail: micniem{at}

Louisa Brock
Ph.D. student
Phone office: +49-(0)30-838-56792
Phone lab: +49-(0)30-838-56874
e-mail: louisa.brock{at}

Tianqi Guo
Ph.D. student
Phone office: +49-(0)30-838-56794
Phone lab: +49-(0)30-838-56874
e-mail: guotianqi03{at}

Jenny Engelmann
Ph.D. student
Phone office: +49-(0)30-838-56792
Phone lab: +49-(0)30-838-56874
e-mail: j.engelmann{at}

Georgeta Leonte
Ph.D. student
Phone office: +49-(0)30-838-56792
Phone lab: +49-(0)30-838-56874
e-mail: getta{at}

Joshua Alcaniz
Master student
Phone office: +49-(0)30-838-56792
Phone lab: +49-(0)30-838-56874
e-mail: joshuaalcaniz{at}

Duc Tung Le
Master student
Phone office: +49-(0)30-838-56792
Phone lab: +49-(0)30-838-56874
e-mail: supernakmachine{at}

Antonia Niedobitek
Master student
Phone office: +49-(0)30-838-56792
Phone lab: +49-(0)30-838-56874
e-mail: antonia.niedobitek{at}

Photograph of the Werner group members
Group photo (2015)
From left to right: Michael, Tomáš, Georgeta, Antonia, Tung, Louisa, Jenny, Joshua, Felicitas, Tianqi

Former members


Niemann M.C.E., Werner T. (2015) Endoplasmic reticulum: Where nucleotide sugar transport meets cytokinin control mechanisms. Plant Signal. Behav. 10: e1072668

Niemann M.C.E., Bartrina I., Ashikov A., Weber H., Novák O., Spíchal L., Strnad M., Strasser R., Bakker H., Schmülling T., Werner T. (2015) Arabidopsis ROCK1 transports UDP-GlcNAc/UDP-GalNAc and regulates ER protein quality control and cytokinin activity. Proc. Natl. Acad. Sci. USA 112: 291-296

Köllmer I., Novák O., Strnad M., Schmülling T., Werner T. (2014) Overexpression of the cytosolic cytokinin oxidase/dehydrogenase (CKX7) from Arabidopsis causes specific changes in root growth and xylem differentiation. Plant J. 78: 359-371

Macková H., Hronková M., Dobrá J., Turečková V., Novák O., Lubovská Z., Motyka V., Haisel D., Hájek T., Prášil I.T., Gaudinová A., Štorchová H., Ge E., Werner T., Schmülling T., Vanková, R. (2013) Enhanced drought and heat stress tolerance of tobacco plants with ectopically enhanced cytokinin oxidase/dehydrogenase gene expression. J. Exp. Bot. 64: 2805-2815

Holst K., Schmülling T., Werner T. (2011) Enhanced cytokinin degradation in leaf primordia of transgenic Arabidopsis plants reduces leaf size and shoot organ primordia formation J. Plant Physiol. 168: 1328-1334

Köllmer I., Werner T., Schmülling T. (2011) Ectopic expression of different cytokinin-regulated transcription factor genes of Arabidopsis thaliana alters plant growth and development. J. Plant Physiol. 168: 1320-1327

Nishiyama R., Watanabe Y., Fujita Y., Le D. T., Kojima M., Werner T., Vankova R., Yamaguchi-Shinozaki K., Shinozaki K., Kakimoto T., Sakakibara H., Schmülling T., Tran L.-S. P. (2011) Analysis of cytokinin mutants and regulation of cytokinin metabolic genes reveals important regulatory roles of cytokinins in drought, salt and abscisic acid responses, and abscisic acid biosynthesis. Plant Cell 23: 2169-2183

Vercruyssen, L., Gonzalez, N., Werner, T., Schmülling, T., Inzé, D. (2011) Combining enhanced root and shoot growth reveals crosstalk between pathways that control plant organ size in Arabidopsis. Plant Physiol.: pp.110.167049

Bartrina, I., Otto, E., Strnad, M., Werner, T., Schmülling, T. (2011) Cytokinin regulates the activity of reproductive meristems, flower organ size, ovule formation, and thus seed yield in Arabidopsis thaliana. Plant Cell 23, 69-80

Werner, T., Nehnevajova, E., Köllmer, I., Novák, O., Strnad, M., Krämer, U., Schmülling, T. (2010) Root-specific reduction of cytokinin causes enhanced root growth, drought tolerance, and leaf mineral enrichment in Arabidopsis and tobacco. Plant Cell 22: 3905-3920

Werner, T., Schmülling, T. (2009) Cytokinin action in plant development. Curr. Opin. Plant Biol. 12: 527-538

Spíchal, L., Werner, T., Popa, I., Riefler, M., Schmülling, T., Strnad, M. (2009). The purine derivative PI-55 blocks cytokinin action via receptor inhibition. FEBS J. 276: 244-253

Werner T., Holst K., Mustroph A., Guivarc'h A., Pörs Y., Chriqui D., Grimm B., Schmülling T. (2008) The influence of cytokinin-deficiency on sink and source parameters. J. Exp. Bot. 59: 2659-2672

Frébortová J., Galuszka P., Werner T., Schmülling T., Frébort I. (2007) Functional expression and purification of cytokinin dehydrogenase from Arabidopsis thaliana (AtCKX2) in Saccharomyces cerevisiae. Biol. Plantarum 51: 673-682

Galuszka P., Popelková H., Werner T., Frébortová J., Pospísilová H., Mik V., Köllmer I., Schmülling T., Frébort I. (2007) Biochemical characterization of cytokinin oxidases/dehydrogenases from Arabidopsis thaliana expressed in Nicotiana tabacum L. J. Plant Growth Regul. 26: 255-267

Riefler M., Heyl A., Werner T. (2007) Cytokinins. In Encyclopedia of life sciences. John Wiley & Sons, Ltd: Chichester (DOI: 10.1002/9780470015902.a0020095)

Heyl A., Werner T., Schmülling T. (2006) Metabolism and signal transduction of cytokinin. In P. Hedden, S. Thomas, eds, Plant hormone signalling, Annual Plant Reviews. Blackwell Publishing Ltd., Oxford, pp 93-123

Werner T., Köllmer I., Bartrina I., Holst K., Schmülling T. (2006) New insights into the biology of cytokinin degradation. Plant Biol. 8: 1-12

Schmülling T., Werner T., Krämer U., Riefler M. (2005) The enhanced root system of cytokinin-deficient plants and its consequences for mineral uptake. In C.J. Li, ed, Plant nutrition for food security, human health and environmental protection. Tsinghua University Press, Beijing, pp 474-475

Galuszka P., Frébortová J., Werner T., Yamada M., Strnad M., Schmülling T., Frébort I. (2004) Cytokinin oxidase/dehydrogenase genes in barley and wheat: cloning and heterologous expression. Eur. J. Biochem. 271: 3990-4002

Schmülling T., Werner T., Riefler M., Krupková E., Bartrina y Manns I. (2003) Structure and function of cytokinin oxidase/dehydrogenase genes of maize, rice, Arabidopsis and other species. J. Plant Res. 116: 241-252

Schmülling T., Werner T., Riefler M., Krupková E., Bartrina y Manns I., Dortay H. (2003) Cytokinin as a regulatory factor for yield and biomass distribution in crop plants. In I. Machácková, G.A. Romanov, eds, Phytohormones in Plant Biotechnology and Agriculture. Kluwer Academic Publishers, Dordrecht/Boston/London, pp 97-108

Werner T., Motyka V., Laucou V., Smets R., Van Onckelen H., Schmülling T. (2003) Cytokinin-deficient transgenic Arabidopsis plants show multiple developmental alterations indicating opposite functions of cytokinins in the regulation of shoot and root meristem activity. Plant Cell 15: 2532-2550

Werner T., Hanus J., Holub J., Schmülling T., van Onckelen H., Strnad M. (2003) ) New cytokinin metabolites in IPT transgenic Arabidopsis thaliana plants. Physiol. Plant. 118: 127-137

Frébort I., Šebela M., Galuszka P., Werner T., Schmülling T., Pec P. (2002) Cytokinin oxidase/cytokinin dehydrogenase assay: Optimized procedures and applications. Anal. Biochem. 306: 1-7

Werner T., Motyka V., Strnad M., Schmülling T. (2001) Regulation of plant growth by cytokinin. Proc. Natl. Acad. Sci. USA 98: 10487-10492

Rupp H.M., Frank M., Werner T., Strnad M., Schmülling T. (1999) Increased steady state mRNA levels of the STM and KNAT1 homeobox genes in cytokinin overproducing Arabidopsis thaliana indicate a role for cytokinins in the shoot apical meristem. Plant J. 18: 557-563


New publication

An article about the analysis of a cytokinin-responsive gene of Arabidopsis thaliana encoding a novel F-box protein regulating sterol biosynthesis has been published in Journal of Experimental Botany.
May 2017

New publication

A report about constitutively active mutants of the cytokinin receptors AHK2 und AHK3 and their impact on organ size, flowering time, and plant longevity has been published in Plant Physiology.
March 2017

New publication

An article about the role of the transcription factor ERF105 in freezing tolerance and cold acclimation has been published in Plant Cell and Environment.
January 2017

Krolow Award 2016

The Krolow Award 2016 was given to Dr. Anne Cortleven for her work about the role of Cytokinin in the plant response to high light stress.
November 2016
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Updated: 2017-04-23