24-Methyl/methylene sterols increase in monoxenic roots after colonization by arbuscular mycorrhizal fungi

Authors

  • J. Fontaine,

    1. Laboratoire Mycologie/Phytopathologie/Environnement, Université du Littoral, Côte d’Opale, BP 699, 62228 Calais cedex, France
    Search for more papers by this author
  • A. Grandmougin-Ferjani,

    Corresponding author
    1. Laboratoire Mycologie/Phytopathologie/Environnement, Université du Littoral, Côte d’Opale, BP 699, 62228 Calais cedex, France
      Author for correspondence: A. Grandmougin-Ferjani Tel: +33 03 21 96 48 07 Fax: +33 03 21 34 71 13 Email: grand@uni-littoral.fr
    Search for more papers by this author
  • V. Glorian,

    1. Laboratoire Mycologie/Phytopathologie/Environnement, Université du Littoral, Côte d’Opale, BP 699, 62228 Calais cedex, France
    Search for more papers by this author
  • R. Durand

    1. Laboratoire Mycologie/Phytopathologie/Environnement, Université du Littoral, Côte d’Opale, BP 699, 62228 Calais cedex, France
    Search for more papers by this author

Author for correspondence: A. Grandmougin-Ferjani Tel: +33 03 21 96 48 07 Fax: +33 03 21 34 71 13 Email: grand@uni-littoral.fr

Summary

  • • Characteristic sterols of transformed carrot (Daucus carota) and chicory (Cichorium intybus) roots colonized by different strains of arbuscular mycorrhizal (AM) fungi were identified.
  • • Sterols were extracted, analysed and identified by gas chromatography/mass spectrometry (GC-MS) from monoxenic cultures of mycorrhizal and nonmycorrhizal roots. After colonization by Glomus intraradices, Glomus proliferum and Glomus sp., carrot and chicory roots exhibited a significantly higher 24-methyl/methylene sterol content. A correlation was established between the content of the sum of 24-methyl cholesterol, 24-methylene cholesterol and 24-methyl desmosterol.
  • • This study clearly established that the increment of these characteristic sterols is an appropriate indicator of colonization by AM fungi of transformed roots.
  • • Metabolic origin and specificity of these sterols in mycorrhizal roots was researched. The 24-methyl/methylene sterol increase was observed only when the interaction between fungus and plant was completely established and the fungus was present inside the roots.

Ancillary