Ectomycorrhizal fungi and mobilisation of phosphorus: novel data and actual role

Autor: Plassard, Claude, Louche, Julien, Ali, M.A., Duchemin, Myriam, Legname, Elvira, Cloutier-Hurteau, Benoît, Tatry, Marie Violaine, El Kassis, Elie
Přispěvatelé: Ecologie Fonctionnelle et Biogéochimie des Sols (Eco&Sols), Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Ecole Nationale Supérieure Agronomique de Montpellier (ENSA M), Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes (UMR Eco&Sols), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA), ProdInra, Migration
Jazyk: angličtina
Rok vydání: 2009
Předmět:
Zdroj: 6. International Conference on Mycorrhiza (ICOM6)
6. International Conference on Mycorrhiza (ICOM6), Aug 2009, Belo Horizonte, Brazil
Popis: International audience; Ectomycorrhizal (ECM) symbiosis improves markedly the P nutrition of the host plant, but the mechanisms sustaining this positive effect are not all understood. In our group, we focused on (1) the identification of fungal P transporters and (2) the role of fungal phosphatase (Pase) released into the soil solution on organic P (Po) mobilisation. To address the first question, we worked on the model fungal ECM species Hebeloma cylindrosporum. We identified two phosphate (Pi) transporters (HcPT1 and HcPT2) able to mediate Pi:H+ symport in yeast with different affinities for Pi. Expression patterns of the two genes in ECM plants grown in a low-P or high-P soil indicate that HcPT1 and HcPT2 might be involved in the uptake of Pi from the soil solution in the two conditions of soil P availability used. To address the second question, we worked on the quantification of Pase released by ECM tips collected in various forest ecosystems through Europe differing by their levels of water and nutrient availability. We used also H. cylindrosporum as this species is able to release huge amounts of Pase activity when grown in vitro in P-starved conditions. The results obtained so far showed that the regulation of Pase activity evaluated in situ is complex. H. cylindrosporum released four acid Pase fractions displaying different efficiency to release Pi from Po extracted from podzol. A novel scheme of the possible role of ECM fungal Pase in Po mobilisation from forest soil will be proposed.
Databáze: OpenAIRE