Jourand Philippe auteur aut IRD Hannibal Laure auteur aut IRD Majorel Clarisse auteur aut IRD Mengant S. auteur aut IRD Ducousso M. auteur aut IRD Lebrun M. auteur aut IRD text journalArticle eng text/pdf born digital access Ectomycorrhizal fungi (ECM) isolates of Pisolithus albus (Cooke and Massee) from nickel-rich ultramafic topsoils in New Caledonia were inoculated onto Acacia spirorbis Labill. (an endemic Fabaceae) and Eucalyptus globulus Labill. (used as a Myrtaceae plant host model). The aim of the study was to analyze the growth of symbiotic ECM plants growing on the ultramafic substrate that is characterized by high and toxic metal concentrations i.e. Co, Cr, Fe, Mn and Ni, deficient concentrations of plant essential nutrients such as N, P, K, and that presents an unbalanced Ca/Mg ratio (1/19). ECM inoculation was successful with a plant level of root mycorrhization up to 6.7%. ECM symbiosis enhanced plant growth as indicated by significant increases in shoot and root biomass. Presence of ECM enhanced uptake of major elements that are deficient in ultramafic substrates; in particular P, K and Ca. On the contrary, the ECM symbioses strongly reduced transfer to plants of element in excess in soils; in particular all metals. ECM-inoculated plants released metal complexing molecules as free thiols and oxalic acid mostly at lower concentrations than in controls. Data showed that ECM symbiosis helped plant growth by supplying uptake of deficient elements while acting as a protective barrier to toxic metals, in particular for plants growing on ultramafic substrate with extreme soil conditions. Isolation of indigenous and stress-adapted beneficial ECM fungi could serve as a potential tool for inoculation of ECM endemic plants for the successful restoration of ultramafic ecosystems degraded by mining activities. specialized SYMBIOSE ECTOMYCORHIZE INOCULATION ARBRE ESPECE ENDEMIQUE CROISSANCE BIOMASSE METAL LOURD TOLERANCE NICKEL NUTRITION MINERALE ADAPTATION RACINE MINE ETUDE EXPERIMENTALE ETUDE COMPARATIVE SOL ULTRAMAFIQUE NOUVELLE CALEDONIE 084SYMBIO03 068PROSOL 171 164-172 2014 0176-1617 https://www.documentation.ird.fr/hor/fdi:010060181 10.1016/j.jplph.2013.10.011 0176-1617 [F B010060181] https://www.documentation.ird.fr/hor/fdi:010060181 https://www.documentation.ird.fr/intranet/publi/depot/2013-11-26/010060181.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2013-11-26 2016-09-05 fdi:010060181 fre