The Arabidopsis SOC1-like genes AGL42, AGL71 and AGL72 promote flowering in the shoot apical and axillary meristems

Authors

  • Carmen Dorca-Fornell,

    1. Dipartimento di Biologia, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
    Search for more papers by this author
    • Present address: Department of Animal and Plant Science, The University of Sheffield, Sheffield S10 2TN, UK.

    • These authors contributed equally to this work.

  • Veronica Gregis,

    1. Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
    Search for more papers by this author
    • These authors contributed equally to this work.

  • Valentina Grandi,

    1. Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
    Search for more papers by this author
  • George Coupland,

    1. Max Planck Institute for Plant Breeding Research, D–50829 Cologne, Germany
    Search for more papers by this author
  • Lucia Colombo,

    1. Dipartimento di Biologia, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
    Search for more papers by this author
  • Martin M. Kater

    Corresponding author
    1. Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
    Search for more papers by this author

(fax +39 02 50315047; e-mail martin.kater@unimi.it).

Summary

The floral transition is the switch from vegetative development to flowering. Proper timing of the floral transition is regulated by different pathways and is critical for the reproductive success of plants. Some of the flowering pathways are controlled by environmental signals such as photoperiod and vernalization, others by autonomous signals such as the developmental state of the plant and hormones, particularly gibberellin. SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1) acts in Arabidopsis as an integrative centre of these pathways, promoting the floral transition. In this work, we show that AGAMOUS-LIKE 42 (AGL42), AGAMOUS-LIKE 71 (AGL71) and AGAMOUS-LIKE 72 (AGL72), which encode MADS-box transcription factors phylogenetically closely related to SOC1, are also involved in the floral transition. They promote flowering at the shoot apical and axillary meristems and seem to act through a gibberellin-dependent pathway. Furthermore SOC1 directly controls the expression of AGL42, AGL71 and AGL72 to balance the expression level of these SOC1-like genes. Our data reveal roles for AGL42, AGL71 and AGL72 in the floral transition, demonstrate their genetic interactions with SOC1 and suggest that their roles differ in the apical and axillary meristems.

Ancillary