Analysis of nif and regulatory genes in Acetobacter diazotrophicus

Sevilla, Myrna; Meletzus, Dietmar; Teixeira, K. R. dos S.; Lee, Sunhee; Nutakki, Anu; Baldani, Ivo; Kennedy, Christina

doi:10.1016/s0038-0717(96)00210-6

Cited by 25 publications

(15 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Transconjugants were picked and stored as libraries in 96-well microtiter plates. The site-directed insertion mutants were generated using the ⍀ fragment (streptomycin) as described previously (41).…”

Section: Methodsmentioning

confidence: 99%

Indole-3-Acetic Acid Biosynthesis Is Deficient in Gluconacetobacter diazotrophicus Strains with Mutations in Cytochrome c Biogenesis Genes

et al. 2004

Self Cite

View full text Add to dashboard Cite

Gluconacetobacter diazotrophicus is an endophyte of sugarcane frequently found in plants grown in agricultural areas where nitrogen fertilizer input is low. Recent results from this laboratory, using mutant strains of G. diazotrophicus unable to fix nitrogen, suggested that there are two beneficial effects of G. diazotrophicus on sugarcane growth: one dependent and one not dependent on nitrogen fixation. A plant growth-promoting substance, such as indole-3-acetic acid (IAA), known to be produced by G. diazotrophicus, could be a nitrogen fixation-independent factor. One strain, MAd10, isolated by screening a library of Tn5 mutants, released only ϳ6% of the amount of IAA excreted by the parent strain in liquid culture. The mutation causing the IAA ؊ phenotype was not linked to Tn5. A pLAFR3 cosmid clone that complemented the IAA deficiency was isolated. Sequence analysis of a complementing subclone indicated the presence of genes involved in cytochrome c biogenesis (ccm, for cytochrome c maturation). The G. diazotrophicus ccm operon was sequenced; the individual ccm gene products were 37 to 52% identical to ccm gene products of Escherichia coli and equivalent cyc genes of Bradyrhizobium japonicum. Although several ccm mutant phenotypes have been described in the literature, there are no reports of ccm gene products being involved in IAA production. Spectral analysis, heme-associated peroxidase activities, and respiratory activities of the cell membranes revealed that the ccm genes of G. diazotrophicus are involved in cytochrome c biogenesis.

show abstract

Section: Methodsmentioning

confidence: 99%

Indole-3-Acetic Acid Biosynthesis Is Deficient in Gluconacetobacter diazotrophicus Strains with Mutations in Cytochrome c Biogenesis Genes

et al. 2004

Self Cite

View full text Add to dashboard Cite

show abstract

“…Molecular studies with A. diazotrophicus revealed that nitrogen fixation genes and regulatory genes (nif and fix genes) have similarities with nif genes of other nitrogenfixing bacteria (Lee et al, 1998;Sevilla et al, 1997). Mutants unable to fix nitrogen could colonize sugarcane plants.…”

Section: Endophytic Diazotrophic Bacteriamentioning

confidence: 99%

Endophytic microorganisms: a review on insect control and recent advances on tropical plants

Azevedo¹,

Maccheroni²,

Pereira³

et al. 2000

Electron. J. Biotechnol.

558

320

View full text Add to dashboard Cite

In the past two decades, a great deal of information on the role of endophytic microorganisms in nature has been collected. The capability of colonizing internal host tissues has made endophytes valuable for agriculture as a tool to improve crop performance. In this review, we addressed the major topics concerning the control of insects-pests by endophytic microorganisms. Several examples of insect control are described, notably those involving the interactions between fungi and grazing grasses from temperate countries. The mechanisms by which endophytic fungi control insect attacks are listed and include toxin production as well as the influence of these compounds on plant and livestock and how their production may be affected by genetic and environmental conditions. The importance of endophytic entomopathogenic fungi for insect control is also addressed. As the literature has shown, there is a lack of information on endophytes from tropical hosts, which are more severely affected by pests and diseases. The natural and biological control of pests and diseases affecting cultivated plants has gained much attention in the past decades as a way of reducing the use of chemical products in agriculture. Biological control has been frequently used in Brazil, supported by the development of basic and applied research on this field not only in our country but also in South America as it can be found in several reviews (Lecuona, 1996;Alves, 1998;Melo and Azevedo, 1998). In fact, by having vast agriculturable areas and most of its territory in the tropical region, Brazil and all Latin America, show their agriculture severely affected by agricultural pests. The use of agrochemicals, although decreasing the attack of insects and phytopathogenic microorganisms, still represents a high risk to field workers and consumers. In addition, their use is, in certain cases, economically unviable. The control of pests and diseases by means of biological processes i. e., use of entomopathogenic microorganisms or those that inhibit/antagonise other microorganisms pathogenic to plants, is an alternative that may contribute to reduce or eliminate the use of chemical products in agriculture.

show abstract

“…In the 90's, many genes involved in nitrogen fixation by G. diazotrophicus were cloned and sequenced (Sevilla et al 1997. The organization of the nif, fix and mop genes is known, however the mechanisms involved in their regulation still needs further study (Lee et al 2000).…”

Section: Genetics Studiesmentioning

confidence: 99%

History on the biological nitrogen fixation research in graminaceous plants: special emphasis on the Brazilian experience

Baldani

2005

An. Acad. Bras. Ciênc.

231

View full text Add to dashboard Cite

This review covers the history on Biological Nitrogen Fixation (BNF) in Graminaceous plants grown in Brazil, and describes research progress made over the last 40 years, most of which was coordinated by Johanna Döbereiner. One notable accomplishment during this period was the discovery of several nitrogen-fixing bacteria such as the rhizospheric (Beijerinckia fluminensis and Azotobacter paspali), associative (Azospirillum lipoferum, A. brasilense, A. amazonense) and the endophytic (Herbaspirillum seropedicae, H. rubrisubalbicans, Gluconacetobacter diazotrophicus, Burkholderia brasilensis and B. tropica). The role of these diazotrophs in association with grasses, mainly with cereal plants, has been studied and a lot of progress has been achieved in the ecological, physiological, biochemical, and genetic aspects. The mechanisms of colonization and infection of the plant tissues are better understood, and the BNF contribution to the soil/plant system has been determined. Inoculation studies with diazotrophs showed that endophytic bacteria have a much higher BNF contribution potential than associative diazotrophs. In addition, it was found that the plant genotype influences the plant/bacteria association. Recent data suggest that more studies should be conducted on the endophytic association to strengthen the BNF potential. The ongoing genome sequencing programs: RIOGENE (Gluconacetobacter diazotrophicus) and GENOPAR (Herbaspirillum seropedicae) reflect the commitment to the BNF study in Brazil and should allow the country to continue in the forefront of research related to the BNF process in Graminaceous plants.

show abstract

Analysis of nif and regulatory genes in Acetobacter diazotrophicus

Cited by 25 publications

References 12 publications

Indole-3-Acetic Acid Biosynthesis Is Deficient in Gluconacetobacter diazotrophicus Strains with Mutations in Cytochrome c Biogenesis Genes

Indole-3-Acetic Acid Biosynthesis Is Deficient in Gluconacetobacter diazotrophicus Strains with Mutations in Cytochrome c Biogenesis Genes

Endophytic microorganisms: a review on insect control and recent advances on tropical plants

History on the biological nitrogen fixation research in graminaceous plants: special emphasis on the Brazilian experience

Contact Info

Product

Resources

About