title: Improving prediction of metal uptake by Chinese cabbage (Brassica pekinensis L.) based on a soil-plant stepwise analysis.
abstract: It is crucial to develop predictive soil-plant transfer (SPT) models to derive the threshold values of toxic metals in contaminated arable soils. The present study was designed to examine the heavy metal uptake pattern and to improve the prediction of metal uptake by Chinese cabbage grown in agricultural soils with multiple contamination by Cd, Cu, Ni, Pb, and Zn. Pot experiments were performed with 25 historically contaminated soils to determine metal accumulation in different parts of Chinese cabbage. Different soil bioavailable metal fractions were determined using different extractants (0.43M HNO3, 0.01M CaCl2, 0.005M DTPA, and 0.01M LWMOAs), soil moisture samplers, and diffusive gradients in thin films (DGT), and the fractions were compared with shoot metal uptake using both direct and stepwise multiple regression analysis. The stepwise approach significantly improved the prediction of metal uptake by cabbage over the direct approach. Strongly pH dependent or nonlinear relationships were found for the adsorption of root surfaces and in root-shoot uptake processes. Metals were linearly translocated from the root surface to the root. Therefore, the nonlinearity of uptake pattern is an important explanation for the inadequacy of the direct approach in some cases. The stepwise approach offers an alternative and robust method to study the pattern of metal uptake by Chinese cabbage (Brassica pekinensis L.).
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of the Chinese Academy of Sciences, Beijing 100049, China; Southern Methodist University, Dallas, USA.
authors.forename: Sha
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of the Chinese Academy of Sciences, Beijing 100049, China. Electronic address: jingsong@issas.ac.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Song
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Gao
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Guizhou Normal University, Guiyang 550001, China; Guizhou Academy of Environmental Science and Designing, Guiyang 550000, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ming-Chao
authors.initials: MC
authors.lastname: Lv
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Gan
authors.initials: G
authors.lastname: Liu
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yun-Yu
authors.initials: YY
authors.lastname: Pan
authors.affiliation: Agri-Environment Branch, Agri-Food and Biosciences Institute, Belfast, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Christie
authors.affiliation: Southern Methodist University, Dallas, USA.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Sun
mesh_terms: D000383:Agriculture; D001682:Biological Availability; D001937:Brassica / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods*; D019216:Metals, Heavy / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D019216:Metals, Heavy; D012989:Soil Pollutants
keywords: Bioavailability; Chinese cabbage; Metal uptake; Model; pH