title: Fungal inoculation and elevated CO2 mediate growth of Lolium mutiforum and Phytolacca americana, metal uptake, and metal bioavailability in metal-contaminated soil: evidence from DGT measurement.
abstract: Fungal inoculation and elevated CO2 may mediate plant growth and uptake of heavy metals, but little evidence from Diffusive Gradients in Thin-films (DGT) measurement has been obtained to characterize the process. Lolium mutiforum and Phytolacca americana were grown at ambient and elevated CO2 on naturally Cd and Pb contaminated soils inoculated with and without Trichoderma asperellum strain C3 or Penicillium chrysogenum strain D4, to investigate plant growth, metal uptake, and metal bioavailability responses. Fungal inoculation increased plant biomass and shoot/root Cd and Pb concentrations. Elevated CO2 significantly increased plants biomass, but decreased Cd and Pb concentrations in shoot/root to various extents, leading to a metal dilution phenomenon. Total Cd and Pb uptake by plants, and DGT-measured Cd and Pb concentrations in rhizosphere soils, were higher in all fungal inoculation and elevated CO2 treatments than control treatments, with the combined treatments having more influence than either treatment alone. Metal dilution phenomenon occurred because the increase in DGT-measured bioavailable metal pools in plant rhizosphere due to elevated CO2 was unable to match the increase in requirement for plant uptake of metals due to plant biomass increase.
authors.affiliation: Centre for Research in Ecotoxicology and Environmental Remediation, Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, P. R. China.
authors.forename: Ningning
authors.initials: N
authors.lastname: Song
authors.forename: Fangli
authors.initials: F
authors.lastname: Wang
authors.forename: Changbo
authors.initials: C
authors.lastname: Zhang
authors.forename: Shirong
authors.initials: S
authors.lastname: Tang
authors.forename: Junkang
authors.initials: J
authors.lastname: Guo
authors.forename: Xuehai
authors.initials: X
authors.lastname: Ju
authors.forename: Donald L
authors.initials: DL
authors.lastname: Smith
mesh_terms: D059827:Agricultural Inoculants; D001483:Base Sequence; D001673:Biodegradation, Environmental; D001682:Biological Availability; D018533:Biomass; D002104:Cadmium / Q000032:analysis / Q000378:metabolism; D002245:Carbon Dioxide / Q000494:pharmacology*; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D007854:Lead / Q000032:analysis / Q000378:metabolism; D008129:Lolium / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D019216:Metals, Heavy / Q000032:analysis / Q000378:metabolism*; D008969:Molecular Sequence Data; D010408:Penicillium chrysogenum / Q000235:genetics / Q000302:isolation & purification*; D029604:Phytolacca americana / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis; D014242:Trichoderma / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004275:DNA, Ribosomal; D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D002245:Carbon Dioxide; D007854:Lead