Characterization of the fixABC region of Azorhizobium caulinodans ORS571 and identification of a new nitrogen fixation gene

ABSTRACT The molecular and physiological mechanisms behind the maturation and maintenance of N2-fixing nodules during development of symbiosis between rhizobia and legumes still remain unclear, although the early events of symbiosis are relatively well understood. Azorhizobium caulinodans ORS571 is a microsymbiont of the tropical legume Sesbania rostrata, forming N2-fixing nodules not only on the roots but also on the stems. In this study, 10,080 transposon-inserted mutants of A. caulinodans ORS571 were individually inoculated onto the stems of S. rostrata, and those mutants that induced ineffective stem nodules, as displayed by halted development at various stages, were selected. From repeated observations on stem nodulation, 108 Tn5 mutants were selected and categorized into seven nodulation types based on size and N2 fixation activity. Tn5 insertions of some mutants were found in the well-known nodulation, nitrogen fixation, and symbiosis-related genes, such as nod, nif, and fix, respectively, lipopolysaccharide synthesis-related genes, C4 metabolism-related genes, and so on. However, other genes have not been reported to have roles in legume-rhizobium symbiosis. The list of newly identified symbiosis-related genes will present clues to aid in understanding the maturation and maintenance mechanisms of nodules.

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Cloning and characterization of the nifA gene from Herbaspirillum seropedicae strain Z78

Canadian Journal of Microbiology ◽

10.1139/m91-069 ◽

1991 ◽

Vol 37 (6) ◽

pp. 425-429 ◽

Cited By ~ 10

Author(s):

Emanuel M. Souza ◽

Shigehiro Funayama ◽

Liu U. Rigo ◽

Fábio O. Pedrosa

Keyword(s):

Nitrogen Fixation ◽

Azospirillum Brasilense ◽

Genomic Library ◽

Acetylene Reduction Activity ◽

Nif Genes ◽

Herbaspirillum Seropedicae ◽

Reduction Activity ◽

Nitrogen Fixation Gene ◽

Nifa Gene

A genomic library of Herbaspirillum seropedicae was constructed and screened for the nifA gene by complementation of a nifA mutant of Azospirillum brasilense (FP10). A recombinant plasmid, pEMS1, capable of restoring acetylene reduction activity in the mutant FP10, was isolated and found to hybridize to the nifA gene of Klebsiella pneumoniae. The results suggest that nifA is involved in the regulation of nif genes in H. seropedicae. Key words: diazotroph, nitrogen fixation gene, nif regulation, complementation cloning, Herbaspirillum seropedicae.

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Characterization of Azorhizobium caulinodans glnB and glnA genes: involvement of the P(II) protein in symbiotic nitrogen fixation.

Journal of Bacteriology ◽

10.1128/jb.179.11.3580-3587.1997 ◽

1997 ◽

Vol 179 (11) ◽

pp. 3580-3587 ◽

Cited By ~ 15

Author(s):

N Michel-Reydellet ◽

N Desnoues ◽

C Elmerich ◽

P A Kaminski

Keyword(s):

Nitrogen Fixation ◽

Symbiotic Nitrogen Fixation ◽

Azorhizobium Caulinodans

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Isolation and characterization of hydrogenase-negative mutants of Azorhizobium caulinodans ORS571

Archives of Microbiology ◽

10.1007/bf00408256 ◽

1988 ◽

Vol 150 (6) ◽

pp. 595-599 ◽

Cited By ~ 5

Author(s):

W. de Vries ◽

J. Ras ◽

H. Stam ◽

M. M. A. van Vlerken ◽

U. Hilgert ◽

...

Keyword(s):

Azorhizobium Caulinodans ◽

Isolation And Characterization ◽

Azorhizobium Caulinodans Ors571

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Glutamine synthetase stabilizes the binding of GlnR to nitrogen fixation gene operators

FEBS Journal ◽

10.1111/febs.14021 ◽

2017 ◽

Vol 284 (6) ◽

pp. 903-918 ◽

Cited By ~ 5

Author(s):

Gabriela de C. Fernandes ◽

Ksenia Hauf ◽

Fernando H. Sant'Anna ◽

Karl Forchhammer ◽

Luciane M. P. Passaglia

Keyword(s):

Nitrogen Fixation ◽

Glutamine Synthetase ◽

Nitrogen Fixation Gene

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COLONIZATION of Rubus glaucus BENTH BY AZORHIZOBIUM CAULINODANS ORS571 USIG A FLAVONOIDE NARINGENINA

BISTUA REVISTA DE LA FACULTAD DE CIENCIAS BASICAS ◽

10.24054/01204211.v2.n2.2016.2117 ◽

2016 ◽

Vol 14 (2) ◽

pp. 15

Author(s):

Giovani Orlando Cancino Escalante ◽

S E Cancino ◽

Enrique Quevedo Garcia

Keyword(s):

Bacterial Colonization ◽

Lateral Roots ◽

Plant Growth Promoting Bacteria ◽

Azorhizobium Caulinodans ◽

Intensity Parameters ◽

Plant Growth Promoting ◽

Measuring Frequency ◽

Northwest Region ◽

Azorhizobium Caulinodans Ors571

Root systems of two Andean blackberry materials (thorn and thornless) of Rubus glaucus Benth cultured in vitro in the presence of five treatments (four flavonoids and one control) were inoculated with Azorhizobium caulinodans ORS571 (pXLGD4) (a strain carrying the lacZ reporter gene which facilitated the detection of bacterial colonization). Evaluation of colonization effectiveness for each treatment was done by means of application of experimental design measuring frequency and intensity parameters. Statistical analysis showed differences at comparing flavonoids vs. control and the overall higher effectiveness of the flavonoid naringenin. Observation of colonization was made by light and electron microscope confirming internal colonization of Andean blackberry roots by A. caulinodans. This is the first work demonstrating root colonization of R.glaucus by azorhizobia and therefore settling the basis for future investigations and scientific applications related to interaction with plant growth-promoting bacteria under the effect of flavonoids, along with possible implications of common benefit for non-legume crops in the northwest region of Colombia. Key Words: Azorhizobium caulinodans ORS571, Andean blackberry, flavonoids, LacZ, lateral roots, naringenin.

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