title: Arsenic uptake, arsenite efflux and plant growth in hyperaccumulator Pteris vittata: Role of arsenic-resistant bacteria.
abstract: Bacteria-mediated arsenic (As) transformation and their impacts on As and P uptake and plant growth in As-hyperaccumulator Pteris vittata (PV) were investigated under sterile condition. All As-resistant bacteria (9 endophytic and 6 rhizospheric) were As-reducers except one As-oxidizer. After growing two months in media with 37.5 mg kg(-1) AsV, As concentrations in the fronds and roots were 3655-5389 (89-91% AsIII) and 971-1467 mg kg(-1) (41-73% AsIII), corresponding to 22-52% decrease in the As in the media. Bacterial inoculation enhanced As and P uptake by up to 47 and 69%, and PV growth by 20-74%, which may be related to elevated As and P in plants (r = 0.88-0.97, p < 0.05). Though AsV was supplied, 95% of the As in the bacteria-free media was AsIII, suggesting efficient efflux of AsIII by PV roots (120 µg g(-1) root fw). This was supported by the fact that no AsV was detected in media inoculated with As-reducers while 95% of AsV was detected with As-oxidizer. Our data showed that, under As-stress, PV reduced As toxicity by efficient AsIII efflux into media and AsIII translocation to the fronds, and bacteria benefited PV growth probably via enhanced As and P uptake.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, China.
authors.forename: Yong-He
authors.initials: YH
authors.lastname: Han
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, China.
authors.forename: Jing-Wei
authors.initials: JW
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, China.
authors.forename: Yanshan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611, United States.
authors.forename: Bala
authors.initials: B
authors.lastname: Rathinasabapathi
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, China; Soil and Water Science Department, University of Florida, Gainesville, FL, 32611, United States. Electronic address: lqma@ufl.edu.
authors.forename: Lena Q
authors.initials: LQ
authors.lastname: Ma
mesh_terms: D001149:Arsenates / Q000493:pharmacokinetics* / Q000494:pharmacology; D001151:Arsenic / Q000378:metabolism; D018053:Arsenites / Q000493:pharmacokinetics* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism*; D004351:Drug Resistance; D010084:Oxidation-Reduction; D063245:Plant Development / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D032495:Pteris / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D012989:Soil Pollutants / Q000493:pharmacokinetics* / Q000494:pharmacology
chemical_list: D001149:Arsenates; D018053:Arsenites; D012989:Soil Pollutants; C015001:arsenite; D001151:Arsenic; C025657:arsenic acid
keywords: Arsenic oxidizing bacteria; Arsenic reducing bacteria; Arsenite efflux; Endophytic bacteria; Pteris vittata; Rhizospheric bacteria