title: Characterization of heavy metal-resistant endophytic bacteria from rape (Brassica napus) roots and their potential in promoting the growth and lead accumulation of rape.
abstract: Two lead (Pb)-resistant endophytic bacteria were isolated from rape roots grown in heavy metal-contaminated soils and characterized. A pot experiment was conducted for investigating the capability of the two isolates to promote the growth and Pb uptake of rape from Pb-amended soil. The two isolates were identified as Pseudomonas fluorescens G10 and Microbacterium sp. G16 based on the 16S rDNA gene sequence analysis. Strains G10 and G16 exhibited different multiple heavy metal and antibiotic resistance characteristics and increased water-soluble Pb in solution and in Pb-added soil. Root elongation assays demonstrated increases in root elongation of inoculated rape seedlings compared to the control plants. Strain G16 produced indole acetic acid, siderophores and 1-aminocyclopropane-1-carboxylate deaminase. Increases in biomass production and total Pb uptake in the bacteria-inoculated plants were obtained compared to the control. The two strains could colonize the root interior and rhizosphere soil of rape after root inoculation.
authors.affiliation: MOA Key Laboratory of Microbiological Engineering of Agricultural Environment, College of Life Science, Nanjing Agricultural University, Nanjing 210095, PR China. xfsheng604@sohu.com
authors.forename: Xia-Fang
authors.initials: XF
authors.lastname: Sheng
authors.forename: Juan-Juan
authors.initials: JJ
authors.lastname: Xia
authors.forename: Chun-Yu
authors.initials: CY
authors.lastname: Jiang
authors.forename: Lin-Yan
authors.initials: LY
authors.lastname: He
authors.forename: Meng
authors.initials: M
authors.lastname: Qian
mesh_terms: D001419:Bacteria / Q000302:isolation & purification* / Q000378:metabolism; D001673:Biodegradation, Environmental; D029688:Brassica napus / Q000254:growth & development / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D004352:Drug Resistance, Microbial; D004463:Ecology / Q000379:methods; D007854:Lead / Q000633:toxicity*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*; D013045:Species Specificity
chemical_list: D012989:Soil Pollutants; D007854:Lead