Partenaires et organisations internationales
(Anglais)
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AT, BE, BG, CH, DE, DK, ES, FI, FR, GR, HU, IE, IT, LT, NO, PT, SE, SI, UK
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Résumé des résultats (Abstract)
(Anglais)
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Arbuscular mycorrhizas are the most common non-pathogenic symbioses in the roots of plants. It is generally assumed that this symbioses played a crucial role in facilitating the colonization of land by plants several hundred million years ago. In arbuscular mycorrhizas, fungal hyphae often extend between the root cells and tuft-like branched structures (arbuscules) form within the cell lumina that act as the functional interface for nutrient exchange. In the mutualistic arbuscular-mycorrhizal (AM) symbiosis the host plant derives mainly phosphorus from the fungus, which in turn benefits from plant-based glucose. The molecular basis of the establishment and functioning of the AM symbiosis is just starting to be understood. In studying the molecular biology of symbiotic phosphorus uptake into the plant we have recently identified the phosphate transporter gene StPT3 in potato (Solanum tuberosum). StPT3 is specifically expressed in root sectors where mycorrhizal structures are formed. In this project, we aim at understanding the molecular mechanisms of Pi transport in tree roots. In a molecular-genetic approach, the StPT3 promoter-GUS reporter gene construct was used to test the hypothesis that the signal perception and transduction pathway leading to the expression of mycorrhiza-specific phosphate transporters is conserved among a wide range of terrestrial plant species including trees. To this end, transgenic poplar plants carrying the StPT3 reporter gene construct have been generated and studied upon cultivation in presence and absence of mycorrhizal fungi. The use of poplar allows the study of plant interactions in their rhizosphere with both endo- and ectomycorrhizal fungi.
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