Soil metatranscriptomics for mining eukaryotic heavy metal resistance genes.

Heavy metals are pollutants which affect all organisms. Since a small number of eukaryotes have been investigated with respect to metal resistance, we hypothesize that many genes that control this phenomenon remain to be identified. This was tested by screening soil eukaryotic metatranscriptomes which encompass RNA from organisms belonging to the main eukaryotic phyla.

OmZnT1 and OmFET, two metal transporters from the metal-tolerant strain Zn of the ericoid mycorrhizal fungus Oidiodendron maius, confer zinc tolerance in yeast.

Two full-length cDNAs (OmZnT1 and OmFET) encoding membrane transporters were identified by yeast functional screening in the heavy metal tolerant ericoid mycorrhizal isolate Oidiodendron maius Zn. OmZnT1 belongs to the Zn-Type subfamily of the cation diffusion facilitators, whereas OmFET belongs to the family of iron permeases. Their properties were investigated in yeast by functional complementation of mutants affected in metal uptake and metal tolerance.