A MADS domain gene involved in the transition to flowering in Arabidopsis

Authors

  • Rony Borner,

    1. Swiss Federal Institute of Technology, Institute for Plant Sciences, Universitätstrasse 2, CH-8092 Zürich, Switzerland, and
    Search for more papers by this author
    • Both authors contributed equally to this work.

  • Grit Kampmann,

    1. Swiss Federal Institute of Technology, Institute for Plant Sciences, Universitätstrasse 2, CH-8092 Zürich, Switzerland, and
    Search for more papers by this author
    • Both authors contributed equally to this work.

  • John Chandler,

    1. Swiss Federal Institute of Technology, Institute for Plant Sciences, Universitätstrasse 2, CH-8092 Zürich, Switzerland, and
    Search for more papers by this author
  • Roland Gleißner,

    1. Swiss Federal Institute of Technology, Institute for Plant Sciences, Universitätstrasse 2, CH-8092 Zürich, Switzerland, and
    Search for more papers by this author
  • Ellen Wisman,

    1. Max-Planck-Institut für Züchtungsforschung, Abteilung Molekulare Pflanzengenetik, Carl-von-Linné-Weg 10, D-50829 Köln, Germany
    Search for more papers by this author
    • Present address: MSU-DOE Plant Research Lab, Michigan State University, 322 Plant Biology, East Lansing, MI 48824-1312, USA.

  • Klaus Apel,

    1. Swiss Federal Institute of Technology, Institute for Plant Sciences, Universitätstrasse 2, CH-8092 Zürich, Switzerland, and
    Search for more papers by this author
  • Siegbert Melzer

    Corresponding author
    1. Swiss Federal Institute of Technology, Institute for Plant Sciences, Universitätstrasse 2, CH-8092 Zürich, Switzerland, and
    Search for more papers by this author

*For correspondence (fax +41 1632 1081; e-mail smelzer@ipw.biol.ethz.ch).

Summary

Flowering time in many plants is triggered by environmental factors that lead to uniform flowering in plant populations, ensuring higher reproductive success. So far, several genes have been identified that are involved in flowering time control. AGL20 (AGAMOUSLIKE20) is a MADS domain gene from Arabidopsis that is activated in shoot apical meristems during the transition to flowering. By transposon tagging we have identified late flowering agl20 mutants, showing that AGL20 is involved in flowering time control. In previously described late flowering mutants of the long-day and constitutive pathways of floral induction the expression of AGL20 is down-regulated, demonstrating that AGL20 acts downstream to the mutated genes. Moreover, we can show that AGL20 is also regulated by the gibberellin (GA) pathway, indicating that AGL20 integrates signals of different pathways of floral induction and might be a central component for the induction of flowering. In addition, the constitutive expression of AGL20 in Arabidopsis is sufficient for photoperiod independent flowering and the over-expression of the orthologous gene from mustard, MADSA, in the classical short-day tobacco Maryland Mammoth bypasses the strict photoperiodic control of flowering.

Ancillary