Acetylene reduction by Rhizobium in pure culture

McComb, J.; Elliott, Jordana; Dilworth, M. J.

doi:10.1038/256409a0

Cited by 141 publications

(45 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The Lb concentrations measured in this study represent total 02-binding protein in nodules, while the acetylene reduction values utilized in the correlation analyses only indicate the presence of active nitrogenase, and not total nitrogenase protein present. Although it has already been demonstrated that Lb is not essential for the development of nitrogenase activity in free-living rhizobia (Kurz and LaRue, 1975;McComb, Elliott and Dilworth, 1975;Pagan et ai., 1975), it remains to be determined whether nitrogenase proteins can be synthesized in the absence of Lb in legurne nodules. Further studies are thus needed to indicate whether the formation of nitrogenase and Lb are directly linked.…”

Section: Functional Relationship Between Nz-jixing Activity and Lb Comentioning

confidence: 99%

A functional relationship between leghaemoglobin and nitrogenase based on novel measurements of the two proteins in legume root nodules

Dakora

1995

Annals of Botany

View full text Add to dashboard Cite

A combination of physiological and structural measurements made on nodulated cowpea and soybean plants cultured with roots in different p02 permitted the expression of da ta in various ways. Values of leghemoglobin concentration and nitrogenase activity from the two legurnes were expressed conventionally either on a per plant or per gram nodule fresh weight basis, and where microscopy was done, on the basis of nitrogenase-containing, N 2-fixing units (i.e. per bacteroid, per infected cell, or per gram infected tissue). In both legumes, acetylene reduction, N fixed and ureide content expressed on the basis of whole plants or per nitrogenase-containing units were very significantly correlated with values ofleghaemoglobin concentrations expressed in a similar manner. The use of mathematical correlations in this study involving leghaemoglobin concentrations and various indices of N 2 fixation indicated a strong functional relationship between the two pro teins in symbiotic legumes. These findings confirm previous suggestions that leghaemoglobin and the nitrogenase complex are two pro teins closely associated with N 2-fixingefficiency in legurne root nodules.

show abstract

Section: Functional Relationship Between Nz-jixing Activity and Lb Comentioning

confidence: 99%

A functional relationship between leghaemoglobin and nitrogenase based on novel measurements of the two proteins in legume root nodules

Dakora

1995

Annals of Botany

View full text Add to dashboard Cite

show abstract

“…Immunological studies (Bishop et al, 1975) indicated that free-living rhizobia were able to synthesize a component of nitrogenase, and nitrogenase activity was subsequently demonstrated in free-living bacteria growing on an air-exposed agar surface (Pagan et al, 1975;Kurz & LaRue, 1975;McComb et al, 1975). Previously, nitrogenase activity had been observed only in what appeared to be loose associations of rhizobia with tissue cultured plant cells (Holsten et a/., 1971;Child & LaRue, 1974;Philips, 1974;Child, 1975;.…”

Section: Introductionmentioning

confidence: 99%

Nitrogenase Activity of Rhizobium japonicum Growing on Agar Surfaces in Relation to Slime Production, Growth and Survival

Wilcockson¹,

Werner²

1978

Journal of General Microbiology

View full text Add to dashboard Cite

“…Under specialized cultural conditions, several bradyrhizobial strains, including B. japonicum, are able to reduce N, to ammonia in free-living culture (Keister, 1975;Pagan et al, 1975;Kurz & Larue, 1975;McComb et al, 1975;Tjepkema & Evans, 1975). Optimal conditions for asymbiotic N2 fixation include the presence of organic acids as carbon and energy source, a growth-promoting nitrogen source, and extreme microaerobiosis.…”

Section: Discussionmentioning

confidence: 99%

“…Some bradyrhizobial strains can be induced to fix N2 in free-living culture under specialized conditions (Keister, 1975;Pagan et al, 1975;Kurz & Larue, 1975;McComb et al, 1975;Tjepkema & Evans, 1975). These conditions include both provision of a source of fixed nitrogen (preferably glutamate) and the presence of O2 as an electron acceptor for oxidative phosphorylation.…”

Section: T H Adams a N D B K Chelmmentioning

confidence: 99%

Effects of Oxygen Levels on the Transcription of nif and gln Genes in Bradyrhizobium japonicum

Adams

Chelm

1988

Microbiology

View full text Add to dashboard Cite

The transciption of genes that function in N2 fixation (nif) and nitrogen assimilation (gln11) in Bradyrhizobiurn japonicum is coordinately induced in response to O2 limitation as well as symbiotic development. We have determined the relative steady-state mRN A levels for the nzfH, nfDK and glnll transcription units in bradyrhizobial cells grown under a variety of levels of aerobiosis and in cells isolated from soybean root nodules. All three transcripts are found in cells grown in a rich medium sparged with O2 concentrations of 5 % (v/v) or less. This expression is qualitatively similar to that observed for Bradyrhizobium during symbiotic development. Potential physiological mechanisms for the coordinate control of these genes are discussed.

show abstract

Acetylene reduction by Rhizobium in pure culture

Cited by 141 publications

References 10 publications

A functional relationship between leghaemoglobin and nitrogenase based on novel measurements of the two proteins in legume root nodules

A functional relationship between leghaemoglobin and nitrogenase based on novel measurements of the two proteins in legume root nodules

Nitrogenase Activity of Rhizobium japonicum Growing on Agar Surfaces in Relation to Slime Production, Growth and Survival

Effects of Oxygen Levels on the Transcription of nif and gln Genes in Bradyrhizobium japonicum

Contact Info

Product

Resources

About