Fungus, mycorrhizal

Paxillus involutus (Batsch) Fr.

Brown roll-rim

An ectomycorrhizal fungus with a broad host range and a model for cadmium studies in mycorrhizal fungi. Associated with poplar on heavily polluted soil it nearly doubles leaf cadmium: unlike Suillus and Pisolithus, here mycorrhiza increases extraction rather than reducing it.

Karelj, Public domain

How it works

Mechanisms: mycorrhizal supportphytoextraction

Contaminants

Contaminant	Evidence	What was shown
Cadmium	greenhouse	Pot experiment with soil from a contaminated site, willow (Salix viminalis) and poplar (Populus canadensis) with three ectomycorrhizal fungi, four replicates: in poplar with P. involutus leaf Cd rose to 2.74 ± 0.34 mg/kg dry matter, nearly 100% above the control, with greater root-to-leaf translocation and greater total extraction. In the mycelium, at 0.05 µM Cd, the metal is distributed between cell wall (50%), cytoplasm (30%) and vacuole (20%). Sell et al. (2005) Contribution of ectomycorrhizal fungi to cadmium uptake of poplars and willows from a heavily polluted soil. Plant Soil, 2005 Blaudez, Botton & Chalot (2000) Cadmium uptake and subcellular compartmentation in the ectomycorrhizal fungus Paxillus involutus. Microbiology 146:1109-1117, 2000

Contaminant

Evidence

What was shown

Cadmium

greenhouse

Pot experiment with soil from a contaminated site, willow (Salix viminalis) and poplar (Populus canadensis) with three ectomycorrhizal fungi, four replicates: in poplar with P. involutus leaf Cd rose to 2.74 ± 0.34 mg/kg dry matter, nearly 100% above the control, with greater root-to-leaf translocation and greater total extraction. In the mycelium, at 0.05 µM Cd, the metal is distributed between cell wall (50%), cytoplasm (30%) and vacuole (20%).

Limits

2.74 mg/kg in leaves is still a low concentration: even doubled, extraction would take a great many harvest cycles. The effect holds for the poplar-P. involutus combination, not in general. The species shows no adaptive zinc tolerance in populations near smelters (Colpaert et al. 2004). The mushroom is poisonous if eaten.