The effect of wheat germ agglutinin on dinitrogen fixation, glutamine synthetase activity and ammonia excretion in Azospirillum brasilense Sp 245

Antonyuk, L. P.

doi:10.1016/0378-1097(93)90116-j

Cited by 3 publications

(5 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…cells . In other studies, N 2 fixation of Azospirillum brasilense Sp -245 was enhanced by the addition of wheat germ agglutinin (Antonyuk et al 1993(Antonyuk et al , 1995Ignatov et al 1995).…”

Section: Nitrogen Fixationmentioning

confidence: 75%

“…Vol. 43, 1997 Azospirillum to plant roots is mediated by lectins, such as wheat germ agglutinin, attached to the bacterial cell surface (Antonyuk et al 1993;Karpati et al 1995).…”

Section: Attachment To Roots and Surfaces And Sites Of Root Colonizationmentioning

confidence: 99%

“…It is also possible that a receptor in Azospirillum brasilense is involved in the binding of wheat germ agglutinin (WGA; one of the most studied plant lectins) (Antonyuk et al 1993). This binding induced changes in the cellular metabolism of Azospirillum brasilense Sp -245 and promoted nitrogen fixation, the excretion of ammonium ions, and the synthesis of IAA (Antonyuk et al 1993(Antonyuk et al , 1995. WGA changed the relative proportion of acidic phospholipids of the membrane.…”

Section: Signal Moleculesmentioning

confidence: 99%

See 2 more Smart Citations

Azospirillum– plant relationships: environmental and physiological advances (1990–1996)

Bashan¹,

Holguín²

1997

Can. J. Microbiol.

547

268

View full text Add to dashboard Cite

This review presents a critical and comprehensive analysis of the developments in environmental and physiological studies related to Azospirillum interactions with plants based on information published between 1990 and 1996. It was designed as an update of a previous review with a similar scope. Apart from an update, this review emphasizes the central issues of Azospirillum research today, such as coinoculation with other microorganisms and hormonal studies, shows the less researched areas, and proposes possible avenues for the exploitation of this bacterium in areas other than agriculture.Key words: Azospirillum, bacterial inoculation, plant–bacteria interaction, plant growth promoting rhizobacteria, rhizosphere bacteria.

show abstract

Section: Nitrogen Fixationmentioning

confidence: 75%

“…Vol. 43, 1997 Azospirillum to plant roots is mediated by lectins, such as wheat germ agglutinin, attached to the bacterial cell surface (Antonyuk et al 1993;Karpati et al 1995).…”

Section: Attachment To Roots and Surfaces And Sites Of Root Colonizationmentioning

confidence: 99%

Section: Signal Moleculesmentioning

confidence: 99%

See 1 more Smart Citation

Azospirillum– plant relationships: environmental and physiological advances (1990–1996)

Bashan¹,

Holguín²

1997

Can. J. Microbiol.

547

268

View full text Add to dashboard Cite

show abstract

“…Wheat germ agglutinin (WGA) has been proposed as a signal molecule in the association between Azospirillum and wheat roots. Binding of WGA was reported to induce changes in the cellular metabolism of A. brasilense Sp245 and promoted N 2 ¢xation, excretion of NH 4 ions and indole-3-acetic acid (IAA) biosynthesis [89,90]. A similar increase of nitrogen ¢xation capability in the presence of WGA has been demonstrated in A. lipoferum [91].…”

Section: Plant Root Interactionmentioning

confidence: 78%

Azospirillum, a free-living nitrogen-fixing bacterium closely associated with grasses: genetic, biochemical and ecological aspects

2000

View full text Add to dashboard Cite

Azospirillum represents the best characterized genus of plant growth-promoting rhizobacteria. Other free-living diazotrophs repeatedly detected in association with plant roots, include Acetobacter diazotrophicus, Herbaspirillum seropedicae, Azoarcus spp. and Azotobacter. Four aspects of the Azospirillum-plant root interaction are highlighted: natural habitat, plant root interaction, nitrogen fixation and biosynthesis of plant growth hormones. Each of these aspects is dealt with in a comparative way. Azospirilla are predominantly surface-colonizing bacteria, whereas A. diazotrophicus, H. seropedicae and Azoarcus sp. are endophytic diazotrophs. The attachment of Azospirillum cells to plant roots occurs in two steps. The polar flagellum, of which the flagellin was shown to be a glycoprotein, mediates the adsorption step. An as yet unidentified surface polysaccharide is believed to be essential in the subsequent anchoring phase. In Azoarcus sp. the attachment process is mediated by type IV pili. Nitrogen fixation structural genes (nif) are highly conserved among all nitrogen-fixing bacteria, and in all diazotrophic species of the class of proteobacteria examined, the transcriptional activator NifA is required for expression of other nif genes in response to two major environmental signals (oxygen and fixed N). However, the mechanisms involved in this control can vary in different organisms. In Azospirillum brasilense and H. seropedicae (alpha- and beta-subgroup, respectively), NifA is inactive in conditions of excess nitrogen. Activation of NifA upon removal of fixed N seems to involve, either directly or indirectly, the signal transduction protein P(II). The presence of four conserved cysteine residues in the NifA protein might be an indication that NifA is directly sensitive to oxygen. In Azotobacter vinelandii (gamma-subgroup) nifA is cotranscribed with a second gene nifL. The nifL gene product inactivates NifA in response to high oxygen tension and cellular nitrogen-status. NifL was found to be a redox-sensitive flavoprotein. The relief of NifL inhibition on NifA activity, in response to N-limitation, is suggested to involve a P(II)-like protein. Moreover, nitrogenase activity is regulated according to the intracellular nitrogen and O(2) level. In A. brasilense and Azospirillum lipoferum posttranslational control of nitrogenase, in response to ammonium and anaerobiosis, involves ADP-ribosylation of the nitrogenase iron protein, mediated by the enzymes DraT and DraG. At least three pathways for indole-3-acetic acid (IAA) biosynthesis in A. brasilense exist: two Trp-dependent (the indole-3-pyruvic acid and presumably the indole-3-acetamide pathway) and one Trp-independent pathway. The occurrence of an IAA biosynthetic pathway not using Trp (tryptophan) as precursor is highly unusual in bacteria. Nevertheless, the indole-3-pyruvate decarboxylase encoding ipdC gene is crucial in the overall IAA biosynthesis in Azospirillum. A number of genes essential for Trp production have been isolated in A. brasilense, including ...

show abstract

“…However, the surplus ammonia, produced by WGA-triggered nitrogen fixation, could be assimilated by an elevated level of GS (12), since the glnBA mRNA is synthesized in larger amounts. Both an enhanced nitrogen fixation, induced by the WGA stimulus, and subsequently an increased level of glutamine synthetase (GS) have been reported in A. brasilense (2).…”

Section: Discussionmentioning

confidence: 99%

Interaction of Azospirillum lipoferum with Wheat Germ Agglutinin Stimulates Nitrogen Fixation

Kárpáti

Kiss²,

Ponyi

et al. 1999

J Bacteriol

View full text Add to dashboard Cite

In vitro, the nitrogen fixation capability of A. lipoferum is efficiently increased in the presence of wheat germ agglutinin (WGA). A putative WGA-binding receptor, a 32-kDa protein, was detected in the cell capsule. The stimulatory effect requiredN-acetyl-d-glucosamine dimer (GlcNAcdi) terminated sugar side chains of the receptor and was dependent on the number of GlcNAcdi links involved in receptor-WGA interface. Binding to the primary sugar binding sites on WGA had a larger stimulatory effect than binding to the secondary sites. The WGA-receptor complex generated stimulus led to elevated transcription of the nifH and nifA genes and of the glnBA gene cluster but not of the glnA gene from its own promoter. There may well be a signalling cascade contributing to the regulation of nitrogen fixation.

show abstract

The effect of wheat germ agglutinin on dinitrogen fixation, glutamine synthetase activity and ammonia excretion in Azospirillum brasilense Sp 245

Cited by 3 publications

References 10 publications

Azospirillum– plant relationships: environmental and physiological advances (1990–1996)

Azospirillum– plant relationships: environmental and physiological advances (1990–1996)

Azospirillum, a free-living nitrogen-fixing bacterium closely associated with grasses: genetic, biochemical and ecological aspects

Interaction of Azospirillum lipoferum with Wheat Germ Agglutinin Stimulates Nitrogen Fixation

Contact Info

Product

Resources

About