title: Genetic diversity of siderophore-producing bacteria of tobacco rhizosphere.
abstract: The genetic diversity of siderophore-producing bacteria of tobacco rhizosphere was studied by amplified ribosomal DNA restriction analysis (ARDRA), 16S rRNA sequence homology and phylogenetics analysis methods. Studies demonstrated that 85% of the total 354 isolates produced siderophores in iron limited liquid medium. A total of 28 ARDRA patterns were identified among the 299 siderophore-producing bacterial isolates. The 28 ARDRA patterns represented bacteria of 14 different genera belonging to six bacterial divisions, namely β-, γ-, α-Proteobacteria, Sphingobacteria, Bacilli, and Actinobacteria. Especially, γ-Proteobacteria consisting of Pseudomonas, Enterobacter, Serratia, Pantoea, Erwinia and Stenotrophomonas genus encountered 18 different ARDRA groups. Results also showed a greater siderophore-producing bacterial diversity than previous researches. For example, Sphingobacterium (isolates G-2-21-1 and G-2-27-2), Pseudomonas poae (isolate G-2-1-1), Enterobacter endosymbiont (isolates G-2-10-2 and N-5-10), Delftia acidovorans (isolate G-1-15), and Achromobacter xylosoxidans (isolates N-46-11HH and N-5-20) were reported to be able to produce siderophores under low-iron conditions for the first time. Gram-negative isolates were more frequently encountered, with more than 95% total frequency. For Gram-positive bacteria, the Bacillus and Rhodococcus were the only two genera, with 1.7% total frequency. Furthermore, the Pseudomonas and Enterobacter were dominant in this environment, with 44.5% and 24.7% total frequency, respectively. It was also found that 75 percent of the isolates that had the high percentages of siderophore units (% between 40 and 60) belonged to Pseudomonas. Pseudomonas sp. G-229-21 screened out in this study may have potential to apply to low-iron soil to prevent plant soil-borne fungal pathogen diseases.
authors.affiliation: College of Life Sciences, Shandong Agricultural University, Key Laboratory of Agricultural Microbiology, Shandong Agricultural University , Tai'an, Shandong, P.R. China 271018 ; Baolingbao Biology co., Ltd , Yucheng, Shandong , P.R.China 251200.
authors.forename: Fang
authors.initials: F
authors.lastname: Tian
authors.forename: Yanqin
authors.initials: Y
authors.lastname: Ding
authors.forename: Hui
authors.initials: H
authors.lastname: Zhu
authors.forename: Liangtong
authors.initials: L
authors.lastname: Yao
authors.forename: Binghai
authors.initials: B
authors.lastname: Du
keywords: ARDRA; genetic diversity; rRNA; sequencing; siderophore; tobacco rhizosphere
references.citation: Nat Rev Microbiol. 2005 Apr;3(4):307-19
references.pmid: 15759041
references.citation: Microbiol Rev. 1992 Dec;56(4):662-76
references.pmid: 1480114
references.citation: Ecology. 1971 Jul;52(4):577-586
references.pmid: 28973811
references.citation: Appl Environ Microbiol. 1994 Jan;60(1):56-63
references.pmid: 16349165
references.citation: Anal Biochem. 1987 Jan;160(1):47-56
references.pmid: 2952030
references.citation: Lett Appl Microbiol. 2003;36(3):177-81
references.pmid: 12581379
references.citation: Microbiol Res. 2008;163(2):173-81
references.pmid: 16735107
references.citation: Nucleic Acids Res. 1980 Oct 10;8(19):4321-5
references.pmid: 7433111
references.citation: Wei Sheng Wu Xue Bao. 2008 May;48(5):631-7
references.pmid: 18652295
references.citation: Science. 1982 Jun 25;216(4553):1376-81
references.pmid: 17798345
references.citation: Environ Microbiol. 2005 Nov;7(11):1796-808
references.pmid: 16232294