Frédéric Lapeyrie

Publications (2)5.63 Total impact

• Article: Transcriptional changes in two types of pre-mycorrhizal roots and in ectomycorrhizas of oak microcuttings inoculated with Piloderma croceum.

  Patrick Frettinger, Jérémy Derory, Sylvie Herrmann, Christophe Plomion, Frédéric Lapeyrie, Ralf Oelmüller, Francis Martin, François Buscot
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  ABSTRACT: The formation of the ectomycorrhiza implies an alteration in gene expression of both the plant and fungal partners, a process which starts before the formation of any symbiotic interface. However, little is known on the regulation pattern occurring in different parts of the root system. Our experimental system consisting of a micropropagated oak with a hierarchical root system was shown to exhibit symbiosis functional traits prior to any mycorrhizal tissue differentiation after the inoculation with the basidiomycete Piloderma croceum. Using a cDNA array, the plant gene regulation was analyzed in the pre-mycorrhizal phase. Seventy-five transcripts showed differential expression in pre-mycorrhizal lateral and principal roots, and both root types exhibited different sets of responsive genes. For transcripts selected according to a statistical analysis, the alteration in gene expression was confirmed by RT-PCR and quantitative real-time PCR. Genes regulated in pre-mycorrhizal lateral roots displayed an almost identical expression in mycorrhizas. In contrast, genes regulated in pre-mycorrhizal principal roots were often regulated differently in ectomycorrhizas. Down-regulation affected most of the regulated genes involved in metabolism, whereas most of the regulated genes related to cell rescue functions, water regulation and defence response were up-regulated. Regulation of such genes could explain the increase of global resistance observed in mycorrhizal plants.
  Planta 02/2007; 225(2):331-40. · 3.00 Impact Factor
• Source

  Available from: Francois Buscot

  Article: Differential expression of two class III chitinases in two types of roots of Quercus robur during pre-mycorrhizal interactions with Piloderma croceum.

  Patrick Frettinger, Sylvie Herrmann, Frédéric Lapeyrie, Ralf Oelmüller, François Buscot
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  ABSTRACT: Expression of two plant chitinase genes, representing members of class III chitinases, was studied in Quercus robur roots during interactions in a pre-mycorrhizal stage with the ectomycorrhizal fungus Piloderma croceum. Chitinase gene expression was compared in lateral roots destined to form ectomycorrhiza, and in principal roots that are not directly involved in mycorrhizal interactions. The transcript level of the first chitinase (QrchitIII-1) was upregulated in lateral roots, whereas no significant differential expression was observed in principal roots. The second chitinase (QrchitIII-2) was regulated neither in lateral nor in principal roots in presence of the fungus. Because P. croceum did not induce significant chitinase responses in principal roots, the enhanced expression of QrchitIII-1 in lateral roots after inoculation may be related to some steps in symbiosis ontogenesis.
  Mycorrhiza 06/2006; 16(3):219-23. · 2.63 Impact Factor