title: Chromate and phosphate inhibited each other's uptake and translocation in arsenic hyperaccumulator Pteris vittata L.
abstract: We investigated the effects of chromate (CrVI) and phosphate (P) on their uptake and translocation in As-hyperaccumulator Pteris vittata (PV). Plants were exposed to 1) 0.10 mM CrVI and 0, 0.25, 1.25, or 2.50 mM P or 2) 0.25 mM P and 0, 0.50, 2.5 or 5.0 mM CrVI for 24 h in hydroponics. PV accumulated 2919 mg/kg Cr in the roots at CrVI₀.₁₀, and 5100 and 3500 mg/kg P in the fronds and roots at P₀.₂₅. When co-present, CrVI and P inhibited each other's uptake in PV. Increasing P concentrations reduced Cr root concentrations by 62-82% whereas increasing CrVI concentrations reduced frond P concentrations by 52-59% but increased root P concentrations by 11-15%. Chromate reduced P transport, with more P being accumulated in PV roots. Though CrVI was supplied, 64-78% and 92-93% CrIII were in PV fronds and roots. Based on X-ray diffraction, Cr₂O₃ was detected in the roots confirming CrVI reduction to CrIII by PV. In short, CrVI and P inhibited each other in uptake and translocation by PV, and CrVI reduction to CrIII in PV roots served as its detoxification mechanism. The finding helps to understand the interactions of P and Cr during their uptake in PV.
authors.affiliation: Soil and Water Science Department, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Letúzia M
authors.initials: LM
authors.lastname: de Oliveira
authors.affiliation: Soil and Water Science Department, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Jason T
authors.initials: JT
authors.lastname: Lessl
authors.affiliation: Soil and Water Science Department, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Julia
authors.initials: J
authors.lastname: Gress
authors.affiliation: Soil and Water Science Department, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Rujira
authors.initials: R
authors.lastname: Tisarum
authors.affiliation: Soil Science Department, Federal University of Lavras, Lavras 37200-000, Brazil.
authors.forename: Luiz R G
authors.initials: LRG
authors.lastname: Guilherme
authors.affiliation: Soil and Water Science Department, University of Florida, Gainesville, FL 32611, USA; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China. Electronic address: lqma@ufl.edu.
authors.forename: Lena Q
authors.initials: LQ
authors.lastname: Ma
mesh_terms: D001151:Arsenic / Q000032:analysis / Q000378:metabolism*; D002840:Chromates / Q000737:chemistry* / Q000378:metabolism; D018527:Hydroponics; D010710:Phosphates / Q000737:chemistry* / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D032495:Pteris / Q000187:drug effects / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis; D014961:X-Ray Diffraction
chemical_list: D002840:Chromates; D010710:Phosphates; D012989:Soil Pollutants; D001151:Arsenic
keywords: Chromium; Pteris vittata; Speciation; Translocation; Uptake