title: Characterization of a novel plant growth-promoting bacteria strain Delftia tsuruhatensis HR4 both as a diazotroph and a potential biocontrol agent against various plant pathogens.
abstract: A novel, plant growth-promoting bacterium Delftia tsuruhatensis, strain HR4, was isolated from the rhizoplane of rice (Oryza sativa L., cv. Yueguang) in North China. In vitro antagonistic assay showed this strain could suppress the growth of various plant pathogens effectively, especially the three main rice pathogens (Xanthomonas oryzae pv. oryzae, Rhizoctonia solani and Pyricularia oryzae Cavara). Treated with strain HR4 culture, rice blast, rice bacterial blight and rice sheath blight for cv. Yuefu and cv. Nonghu 6 were evidently controlled in the greenhouse. Strain HR4 also showed a high nitrogen-fixing activity in N-free Döbereiner culture medium. The acetylene reduction activity and 15N2-fixing activity (N2FA) were 13.06 C2H4 nmolml(-1) h(-1) and 2.052 15Na.e.%, respectively. The nif gene was located in the chromosome of this strain. Based on phenotypic, physiological, biochemical and phylogenetic studies, strain HR4 could be classified as a member of D. tsuruhatensis. However, comparisons of characteristics with other known species of the genus Delftia suggested that strain HR4 was a novel dizotrophic PGPB strain.
authors.affiliation: College of Life Sciences, Capital Normal University, No.105, Xisanhuan Beilu, Beijing 100037, PR China.
authors.forename: Jigang
authors.initials: J
authors.lastname: Han
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
authors.forename: Xiuzhu
authors.initials: X
authors.lastname: Dong
authors.forename: Zhengqiu
authors.initials: Z
authors.lastname: Cai
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Sun
authors.forename: Hailian
authors.initials: H
authors.lastname: Yang
authors.forename: Yunshan
authors.initials: Y
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Song
mesh_terms: D000898:Antibiosis; D001482:Base Composition; D002681:China; D002876:Chromosomes, Bacterial / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D042742:Delftia / Q000737:chemistry / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D005227:Fatty Acids / Q000032:analysis / Q000302:isolation & purification; D005798:Genes, Bacterial / Q000235:genetics; D005800:Genes, Fungal; D020459:Genes, rRNA; D020082:Magnaporthe / Q000187:drug effects / Q000254:growth & development; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation / Q000235:genetics; D012275:Oryza / Q000382:microbiology; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D010937:Plant Growth Regulators / Q000096:biosynthesis*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012232:Rhizoctonia / Q000187:drug effects / Q000254:growth & development; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D014974:Xanthomonas / Q000187:drug effects / Q000254:growth & development
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D010937:Plant Growth Regulators; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S