title: Elevated atmospheric CO2 affected photosynthetic products in wheat seedlings and biological activity in rhizosphere soil under cadmium stress.
abstract: The objective of this study was to investigate the effects of elevated CO2 (700 ± 23 μmol mol(-1)) on photosynthetic products in wheat seedlings and on organic compounds and biological activity in rhizosphere soil under cadmium (Cd) stress. Elevated CO2 was associated with decreased quantities of reducing sugars, starch, and soluble amino acids, and with increased quantities of soluble sugars, total sugars, and soluble proteins in wheat seedlings under Cd stress. The contents of total soluble sugars, total free amino acids, total soluble phenolic acids, and total organic acids in the rhizosphere soil under Cd stress were improved by elevated CO2. Compared to Cd stress alone, the activity of amylase, phenol oxidase, urease, L-asparaginase, β-glucosidase, neutral phosphatase, and fluorescein diacetate increased under elevated CO2 in combination with Cd stress; only cellulase activity decreased. Bacterial abundance in rhizosphere soil was stimulated by elevated CO2 at low Cd concentrations (1.31-5.31 mg Cd kg(-1) dry soil). Actinomycetes, total microbial abundance, and fungi decreased under the combined conditions at 5.31-10.31 mg Cd kg(-1) dry soil. In conclusion, increased production of soluble sugars, total sugars, and proteins in wheat seedlings under elevated CO2 + Cd stress led to greater quantities of organic compounds in the rhizosphere soil relative to seedlings grown under Cd stress only. Elevated CO2 concentrations could moderate the effects of heavy metal pollution on enzyme activity and microorganism abundance in rhizosphere soils, thus improving soil fertility and the microecological rhizosphere environment of wheat under Cd stress.
authors: School of Environmental Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecological Effect 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, No. 126, Yanta Road, Xi'an, People's Republic of China. jiaxianavy@163.com.
authors: Xia
authors: X
authors: Jia
authors: School of Environmental Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecological Effect 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, No. 126, Yanta Road, Xi'an, People's Republic of China.
authors: Tuo
authors: T
authors: Liu
authors: The School of Earth Science and Resources, Chang'an University, No. 126, Yanta Road, Xi'an, 710054, People's Republic of China.
authors: Yonghua
authors: Y
authors: Zhao
authors: School of Environmental Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecological Effect 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, No. 126, Yanta Road, Xi'an, People's Republic of China.
authors: Yunhua
authors: Y
authors: He
authors: School of Environmental Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecological Effect 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, No. 126, Yanta Road, Xi'an, People's Republic of China.
authors: Mingyan
authors: M
authors: Yang
mesh_terms: D002104:Cadmium / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D002245:Carbon Dioxide / Q000032:analysis*; D010788:Photosynthesis / Q000187:drug effects*; D058441:Rhizosphere; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D014908:Triticum / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D002245:Carbon Dioxide
keywords: Cd-contaminated soil; Elevated atmospheric CO2; Organic compounds; Photosynthetic products; Rhizosphere soil; Soil biological activity; Wheat seedlings