title: [Influence of aluminum and manganese on the growth, nutrient uptake and the efflux by ectomycorrhizal fungi].
abstract: Al3+ and Mn2+ limit forest growth and vegetation restoration in strongly acidic soils and mining areas of aluminum and manganese. The knowledge on the influence of these two elements on ectomycorrhizal fungi can provide theoretical and technical supports for the selection of powerful ectomycorrhizal fungal strains and the bioremediation of contaminated soil. Three ectomycorrhizal fungal strains, namely Suillus luteus 13 (Sl 13), Cenococcum geophilum 04 (Cg 04) and Pisolithus tinctorius 715 (Pt 715), were grown in liquid culture mediums with Al3+ and Mn2+ added alone and together to investigate fungal growth, nutrient uptake and organic acid efflux. The results showed that the biomass of Sl 13, Cg 04 and Pt 715 was decreased by 70.35%, 52.44% and 18.55%, respectively, under Mn2+ stress. Al3 also decreased the biomass of Sl 13 by 50.74% but increased that of Cg 04. The growth of ectomycorrhizal fungi was further inhibited when grown in culture solutions with addition of both Mn2+ and Al3 and the least growth inhibition was found with Pt 715. Cg 04 might thus have a strong resistance to Al3+ stress and Pt 715 to both Al3+ and Mn2+ compared to the others. Al3+ and Mn2+ decreased the nutrient uptake by the fungi, particularly by Sl 13 which showed more obvious reduction than Pt 715 and Cg 04. However, Al3+ and Mn2+ increased the efflux of oxalic acid and protons by ectomycorrhizal fungi. An additional oxalic acid exudation by Cg 04 was observed in the coexistence of Al3+ and Mn2+ and Pt 715 exuded not only oxalic acid but also succinic acid. Therefore, ectomycorrhizal fungi resistant to Mn2+ and Al3+ could effuse more organic acids than the sensitive ones in order to alleviate the harmfulness through complexation under the stress.
authors.affiliation: College of Resources and Environment, Southwest University, Chongqing 400716, China. 1056307239@qq.com
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Huang
authors.forename: Ling
authors.initials: L
authors.lastname: Yuan
mesh_terms: D000535:Aluminum / Q000737:chemistry* / Q000302:isolation & purification; D001673:Biodegradation, Environmental; D008345:Manganese / Q000737:chemistry* / Q000302:isolation & purification; D038821:Mycorrhizae / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D012989:Soil Pollutants; D008345:Manganese; D000535:Aluminum