Fungal Soil Community Targeted loci

Copper (Cu)-based fungicides have been used in viticulture to prevent downy mildew since the end of the 19th century, and are still used nowadays to reduce fungal diseases. Consequently, Cu has built up in many vineyard soils, and it is still unclear how this affects soil functioning. The aim of the present study was to assess the effects of Cu contamination on the soil fungal community.Two contrasting agricultural soils, an acidic sandy loam and an alkaline silt loam, were used for an eco-toxicological greenhouse pot experiment. The soils were spiked with a Cu-based fungicide in seven concentrations (0-5000 mg Cu kg-1 soil) and alfalfa was grown in the pots for 3 months.Sampling was conducted at the beginning and at the end of the study period to test copper’s soil microbial toxicity in total microbial biomass and basal respiration as well as enzyme activities. Fungal abundance was analysed by ergosterol at both samplings. At the second sampling, fungal community structure was evaluated via ITS amplicon sequences.Soil microbial biomass C as well as microbial respiration rate decreased with increasing Cu concentrations. Oxidative extracellular enzymes showed a trend of increasing activity at the first sampling, but a decline in peroxidase activity was observed at the second sampling. We found remarkable Cu-induced changes in the community abundance and composition, but not in diversity. A high number of diverse fungi were able to thrive under elevated Cu concentrations, though the order of Hypocreales declined. In summary, our results showed distinct Cu toxicity effects on soil fungal community structure, which was more pronounced for the acidic soil.