title: Arsenic transformation and plant growth promotion characteristics of As-resistant endophytic bacteria from As-hyperaccumulator Pteris vittata.
abstract: The ability of As-resistant endophytic bacteria in As transformation and plant growth promotion was determined. The endophytes were isolated from As-hyperaccumulator Pteris vittata (PV) after growing for 60 d in a soil containing 200 mg kg(-1) arsenate (AsV). They were isolated in presence of 10 mM AsV from PV roots, stems, and leaflets, representing 4 phyla and 17 genera. All endophytes showed at least one plant growth promoting characteristics including IAA synthesis, siderophore production and P solubilization. The root endophytes had higher P solubilization ability than the leaflet (60.0 vs. 18.3 mg L(-1)). In presence of 10 mM AsV, 6 endophytes had greater growth than the control, suggesting As-stimulated growth. Furthermore, root endophytes were more resistant to AsV while the leaflet endophytes were more tolerant to arsenite (AsIII), which corresponded to the dominant As species in PV tissues. Bacterial As resistance was positively correlated to their ability in AsV reduction but not AsIII oxidation. The roles of those endophytes in promoting plant growth and As resistance in P. vittata warrant further investigation.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China; Geological Survey of Jiangsu Province, Jiangsu 210018, China.
authors.forename: Jia-Yi
authors.initials: JY
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, 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 210046, China.
authors.forename: Yanshan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China.
authors.forename: Ling-Jia
authors.initials: LJ
authors.lastname: Zhu
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
mesh_terms: D001149:Arsenates / Q000032:analysis; D001151:Arsenic / Q000032:analysis* / Q000494:pharmacology; D018053:Arsenites / Q000032:analysis; D001419:Bacteria / Q000254:growth & development / Q000302:isolation & purification*; D024881:Drug Resistance, Bacterial; D060026:Endophytes / Q000254:growth & development / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D010802:Phylogeny; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology; D018547:Plant Stems / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology; D032495:Pteris / Q000187:drug effects / Q000254:growth & development* / Q000382:microbiology; D012989:Soil Pollutants / Q000032:analysis* / Q000494:pharmacology
chemical_list: D001149:Arsenates; D018053:Arsenites; D012989:Soil Pollutants; C015001:arsenite; D001151:Arsenic; C025657:arsenic acid
keywords: Arsenic resistance; Endophytic bacteria; Oxidation; Pteris vittata; Reduction