Alleviating the toxicity of heavy metals by combined amendments in cultivated bag of Pleurotus cornucopiae.

The substrate of mushroom can be polluted with heavy metals and subsequently contaminate mushroom, which requires alternative solutions to reduce associated environmental and human health risks. The effects of amendment application on alleviating Cu and Cd toxicities to Pleurotus cornucopiae were investigated in a cultivated bag experiment conducted with the naturally contaminated substrate. Addition of combined amendments (sodium bentonite, silicon fertilizer, activated carbon, and potassium dihydrogen phosphate) increased the P. cornucopiae biomass and substrate pH. Cu and Cd concentration in P. cornucopiae as well as the available Cu and Cd in substrate reduced for the presence of amendments, and the silicon fertilizer had the biggest inhibition on metal uptake. The smallest amount of Cu and Cd in P. cornucopiae was only 30.8 and 5.51% of control, respectively. Moreover, application of amendments also decreased malondialdehyde (MDA) and hydrogen peroxide (H2O2) level in metal-stressed mushroom by 4.38-53.74 and 8.90-58.42% relative to control, respectively. The decreased oxidative stress could well contribute to the growth of P. cornucopiae, and the elevated substrate pH might lead to the lower metal availability, thus resulting in the reduction of metal accumulation in mushroom. These above results suggest that application of combined amendments in mushroom substrate could be implemented in a general scheme aiming at controlling metal content in P. cornucopiae.