title: Zinc Resistance Mechanisms of P1B-type ATPases in Sinorhizobium meliloti CCNWSX0020.
abstract: The Sinorhizobium meliloti (S. meliloti) strain CCNWSX0020 displayed tolerance to high levels exposures of multiple metals and growth promotion of legume plants grown in metal-contaminated soil. However, the mechanism of metal-resistant strain remains unknown. We used five P1B-ATPases deletions by designating as ∆copA1b, ∆fixI1, ∆copA3, ∆zntA and ∆nia, respectively to investigate the role of P1B-ATPases in heavy metal resistance of S. meliloti. The ∆copA1b and ∆zntA mutants were sensitive to zinc (Zn), cadmium (Cd) and lead (Pb) in different degree, whereas the other mutants had no significant influence on the metal resistance. Moreover, the expression of zntA was induced by Zn, Cd and Pb whereas copA1b was induced by copper (Cu) and silver (Ag). This two deletions could led to the increased intracellular concentrations of Zn, Pb and Cd, but not of Cu. Complementation of ∆copA1b and ∆zntA mutants showed a restoration of tolerance to Zn, Cd and Pb to a certain extent. Taken together, the results suggest an important role of copA1b and zntA in Zn homeostasis and Cd and Pb detoxification in S. meliloti CCNWSX0020.
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A and F University, Yangling, Shaanxi, China.
authors.forename: Mingmei
authors.initials: M
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A and F University, Yangling, Shaanxi, China.
authors.forename: Zhefei
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A and F University, Yangling, Shaanxi, China.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Liang
authors.affiliation: College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
authors.forename: Christopher
authors.initials: C
authors.lastname: Rensing
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A and F University, Yangling, Shaanxi, China.
authors.forename: Gehong
authors.initials: G
authors.lastname: Wei
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism; D007854:Lead / Q000378:metabolism; D009154:Mutation; D010802:Phylogeny; D016962:Sinorhizobium meliloti / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D012989:Soil Pollutants / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D000251:Adenosine Triphosphatases; D015032:Zinc