title: Antimony uptake, translocation and speciation in rice plants exposed to antimonite and antimonate.
abstract: Antimony (Sb) accumulation in rice is a potential threat to human health, but its uptake mechanisms are unclear. A hydroponic experiment was conducted to investigate uptake, translocation, speciation and subcellular distribution of Sb in rice plants exposed to antimonite (SbIII) and antimonate (SbV) at 0.2, 1.0 or 5.0 mg/L for 4h. More Sb was accumulated in iron plaque than in the plant, with both the roots (~10-12 times) and Fe plaque (~28-54 times) sequestering more SbIII than SbV. The presence of iron plaque decreased uptake of both SbV and SbIII. SbIII uptake kinetics fitted better to the Michaelis-Menten function than SbV. Antimonate (56 to 98%) was the predominant form in rice plant with little methylated species being detected using HPLC-ICP-MS. Cell walls accumulated more Sb than organelles and cytosol, which were considered as the first barrier against Sb entering into cells. Sb transformation and subcellular distribution can help to understand the metabolic mechanisms of Sb in rice.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China.
authors.forename: Jing-Hua
authors.initials: JH
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China; Soil and Water Science Department, University of Florida, Gainesville, FL 32611, USA. Electronic address: lqma@ufl.edu.
authors.forename: Lena Q
authors.initials: LQ
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China.
authors.forename: Hong-Jie
authors.initials: HJ
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China. Electronic address: esluojun@nju.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Luo
mesh_terms: D000965:Antimony / Q000032:analysis / Q000378:metabolism*; D004784:Environmental Monitoring; D012275:Oryza / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D000965:Antimony
keywords: Antimony; Iron plaque; Rice plants; Speciation; Subcellular distribution; Uptake