Fomina Marina, Charnock John M, Hillier Stephen, Alexander Ian J, Gadd Geoffrey M
Division of Environmental and Applied Biology, Biological Sciences Institute, School of Life Sciences, University of Dundee, Dundee, DD1 4HN, Scotland, UK.
Microb Ecol. 2006 Aug;52(2):322-33. doi: 10.1007/s00248-006-9004-5. Epub 2006 May 19.
In this research, we investigate zinc phosphate transformations by Paxillus involutus/pine ectomycorrhizas using zinc-resistant and zinc-sensitive strains of the ectomycorrhizal fungus under high- and low-phosphorus conditions to further understand fungal roles in the transformation of toxic metal minerals in the mycorrhizosphere. Mesocosm experiments with ectomycorrhizas were performed under sterile conditions with zinc phosphate localized in cellophane bags: zinc and phosphorus mobilization and uptake by the ectomycorrhizal biomass were analyzed. In the presence of a phosphorus source, an ectomycorrhizal association with a zinc-resistant strain accumulated the least zinc compared to a zinc-sensitive ectomycorrhizal association and non-mycorrhizal plants. Under low-phosphorus conditions, mycorrhizal seedlings infected with the zinc-resistant strain increased the dissolution of zinc phosphate and zinc accumulation by the plant. Extended X-ray absorption fine structure analysis of both mycorrhizal and nonmycorrhizal roots showed octahedral coordination of zinc by oxygen-containing ligands such as carboxylates or phosphate. We conclude that zinc phosphate solubilization and zinc and phosphorus uptake by the association depend on ectomycorrhizal infection, strain of the mycobiont, and the phosphorus status of the matrix.
在本研究中，我们利用外生菌根真菌的耐锌和锌敏感菌株，在高磷和低磷条件下，研究了卷缘桩菇/松树外生菌根对磷酸锌的转化作用，以进一步了解真菌在菌根际有毒金属矿物转化中的作用。在无菌条件下，将磷酸锌置于玻璃纸袋中，进行外生菌根的中宇宙实验：分析外生菌根生物量对锌和磷的活化及吸收情况。在有磷源存在的情况下，与锌敏感外生菌根组合及非菌根植物相比，与耐锌菌株形成的外生菌根组合积累的锌最少。在低磷条件下，感染耐锌菌株的菌根幼苗增加了磷酸锌的溶解及植物对锌的积累。对菌根和非菌根根的扩展X射线吸收精细结构分析表明，锌与羧酸盐或磷酸盐等含氧配体呈八面体配位。我们得出结论，该组合对磷酸锌的溶解以及对锌和磷的吸收取决于外生菌根感染、菌根真菌的菌株以及基质的磷状况。
