Plant Cell, Tissue and Organ Culture

, Volume 90, Issue 3, pp 325–330 | Cite as

Use of fused gfp and gus reporters for the recovery of transformed Medicago truncatula somatic embryos without selective pressure

  • Ana Sofia Duque
  • Susana de Sousa Araújo
  • Matilde Ataíde CordeiroEmail author
  • Dulce Maria Santos
  • Manuel Pedro Fevereiro
Original Paper


We developed an alternative methodology for in vitro selection of transgenic Medicago truncatula cv. Jemalong plants using a bifunctional construct in which the coding sequences for the green fluorescent protein (GFP) and the β-glucuronidase protein (GUS) are fused. An Agrobacterium-mediated transformation protocol was used followed by regeneration via somatic embryogenesis in the dark, to avoid the synthesis and the consequent autofluorescence of chlorophyll. This method is a clear advantage over antibiotic and herbicide selection in which survival of non-transformed tissue is commonly reported, with the reassurance that all the somatic embryos selected as GFP positive are transformed. This was subsequently corroborated by the detection of GUS activity in leaves, stems and roots of the regenerated plants. Without antibiotic selection, and performing the embryo induction in the dark, it was possible to attest the advantage of using GFP as an in vivo detectable reporter for early embryo selection. The fusion with the GUS coding sequence provided additional evidence for the transformation of the previously selected embryos.


Agrobacterium-mediated transformation Antibiotic-free Dark embryo induction 



Green fluorescent protein




Embryo induction medium


Embryo proliferation medium


Embryo conversion medium



S. Duque (BD/1164/2000), S. Araújo (BD/5225/2001) and D. Santos (BPD/21968/2005), are supported by Fundação para a Ciência e Tecnologia, Portugal. The authors wish to thank Dr. H. Spaink (Institute of Molecular Plant Sciences, Leiden) for providing the plasmid pMP2482. We also wish to thank to Dr. A. M. Vieira (Instituto Gulbenkian da Ciência, Oeiras) for helping with the software of image acquisition.


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Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Ana Sofia Duque
    • 1
  • Susana de Sousa Araújo
    • 1
  • Matilde Ataíde Cordeiro
    • 1
    Email author
  • Dulce Maria Santos
    • 1
  • Manuel Pedro Fevereiro
    • 1
    • 2
  1. 1.Laboratory of Plant Cell BiotechnologyInstituto de Tecnologia Química e Biológica (ITQB)OeirasPortugal
  2. 2.Departamento de Biologia VegetalFaculdade de Ciências da Universidade de LisboaLisboaPortugal

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