zinc-adapted fungus protects pines from zinc stress

• Published in: The New phytologist 2004-02, Vol.161 (2), p.549-555
• Main Authors: Adriaensen, K, Lelie, D. van der, Laere, A. van, Vangronsveld, J, Colpaert, J.V
• Format: Article
• Language: English
• Subjects: ammonium compounds; Animal, plant and microbial ecology; Applied ecology; Biodegradation of pollutants; Biological and medical sciences; Biotechnology; Ecotoxicology, biological effects of pollution; ectomycorrhizae; ectomycorrhizal symbiosis; Effects of pollution and side effects of pesticides on plants and fungi; Environment and pollution; forest trees; Fundamental and applied biological sciences. Psychology; Fungal biomass; Fungi; Genotypes; host plants; Industrial applications and implications. Economical aspects; metal tolerance; Nutrient uptake; phosphates; phytoremediation; Pine trees; Pinus sylvestris; Pinus sylvestris (Scots pine); plant stress; Plants; pollutants; Seedlings; Soil pollution; Suillus bovinus; tissue distribution; Toxicity; transpiration; Zinc; Zn tolerance; Zn toxicity
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1046/j.1469-8137.2003.00941.x

• Here we investigated zinc tolerance of ectomycorrhizal Scots pine (Pinus sylvestris) seedlings. An ectomycorrhizal genotype of Suillus bovinus, collected from a Zn-contaminated site and showing adaptive Zn tolerance in vitro, was compared with a nonadapted isolate from a nonpolluted area. • A dose-response experiment was performed. Dynamics of plant and fungal development, and phosphate and ammonium uptake capacity, were assessed under increasing Zn stress. Effects of Zn on transpiration, nutrient content and Zn accumulation were analysed. • Significant Zn-inoculation interaction effects were observed for several responses measured, including uptake rates of phosphate and ammonium; phosphorus, iron and Zn content in shoots; transpiration; biomass of external mycelia; and fungal biomass in roots. • The Zn-tolerant S. bovinus genotype was particularly efficient in protecting pines from Zn stress. The growth of a Zn-sensitive genotype from a normal wild-type population was inhibited at high Zn concentrations, and this isolate could not sustain the pines' acquisition of nutrients. This study shows that well adapted microbial root symbionts are a major component of the survival strategy of trees that colonize contaminated soils.