title: Elevated CO2increases glomalin-related soil protein (GRSP) in the rhizosphere of Robinia pseudoacacia L. seedlings in Pb- and Cd-contaminated soils.
abstract: Glomalin-related soil protein (GRSP), which contains glycoproteins produced by arbuscular mycorrhizal fungi (AMF), as well as non-mycorrhizal-related heat-stable proteins, lipids, and humic materials, is generally categorized into two fractions: easily extractable GRSP (EE-GRSP) and total GRSP (T-GRSP). GRSP plays an important role in soil carbon (C) sequestration and can stabilize heavy metals such as lead (Pb), cadmium (Cd), and manganese (Mn). Soil contamination by heavy metals is occurring in conjunction with rising atmospheric CO2in natural ecosystems due to human activities. However, the response of GRSP to elevated CO2combined with heavy metal contamination has not been widely reported. Here, we investigated the response of GRSP to elevated CO2in the rhizosphere of Robinia pseudoacacia L. seedlings in Pb- and Cd-contaminated soils. Elevated CO2(700 μmol mol-1) significantly increased T- and EE- GRSP concentrations in soils contaminated with Cd, Pb or Cd + Pb. GRSP contributed more carbon to the rhizosphere soil organic carbon pool under elevated CO2+ heavy metals than under ambient CO2. The amount of Cd and Pb bound to GRSP was significantly higher under elevated (compared to ambient) CO2; and elevated CO2increased the ratio of GRSP-bound Cd and Pb to total Cd and Pb. However, available Cd and Pb in rhizosphere soil under increased elevated CO2compared to ambient CO2. The combination of both metals and elevated CO2led to a significant increase in available Pb in rhizosphere soil compared to the Pb treatment alone. In conclusion, increased GRSP produced under elevated CO2could contribute to sequestration of soil pollutants by adsorption of Cd and Pb.
authors.affiliation: School of Environmental Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of Ministry of Education, Key Laboratory of Environmental Protection & Pollution and Remediation of Water and Soil of Shaanxi Province, Chang'an University, Xi'an 710054, PR China. Electronic address: jiaxianavy@163.com.
authors.forename: Xia
authors.initials: X
authors.lastname: Jia
authors.affiliation: The School of Earth Science and Resources, Chang'an University, Xi'an 710054, PR China.
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: School of Environmental Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of Ministry of Education, Key Laboratory of Environmental Protection & Pollution and Remediation of Water and Soil of Shaanxi Province, Chang'an University, Xi'an 710054, PR China.
authors.forename: Tuo
authors.initials: T
authors.lastname: Liu
authors.affiliation: School of Environmental Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of Ministry of Education, Key Laboratory of Environmental Protection & Pollution and Remediation of Water and Soil of Shaanxi Province, Chang'an University, Xi'an 710054, PR China.
authors.forename: Shuping
authors.initials: S
authors.lastname: Huang
authors.affiliation: School of Environmental Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of Ministry of Education, Key Laboratory of Environmental Protection & Pollution and Remediation of Water and Soil of Shaanxi Province, Chang'an University, Xi'an 710054, PR China.
authors.forename: Yafei
authors.initials: Y
authors.lastname: Chang
mesh_terms: D001272:Atmosphere / Q000737:chemistry; D002104:Cadmium / Q000737:chemistry*; D002245:Carbon Dioxide / Q000494:pharmacology*; D017753:Ecosystem; D004787:Environmental Pollution; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D007854:Lead / Q000737:chemistry*; D019216:Metals, Heavy; D038821:Mycorrhizae / Q000187:drug effects / Q000378:metabolism; D058441:Rhizosphere; D031301:Robinia / Q000382:microbiology; D036226:Seedlings / Q000382:microbiology; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry*
chemical_list: D005656:Fungal Proteins; D006023:Glycoproteins; D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; C573268:glomalin; D002104:Cadmium; D002245:Carbon Dioxide; D007854:Lead
keywords: Cd-contaminated soils; Elevated atmospheric CO(2); Glomalin-related soil protein; Pb-contaminated soils; Rhizosphere; Robinia pseudoacacia L. seedlings