Characterization of <i>Azospirillum</i> associated with maize (<i>Zea mays</i>) in France, using biochemical tests and plasmid profiles

Penot, Isabelle; Berges, Nathalie; Guinguene, Christine; Fages, Jacques

doi:10.1139/m92-130

Cited by 18 publications

(11 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the present study, we describe the phenotypic switching in A. lipoferum. In the genus Azospirillum, DNA restriction pattern analysis [19], RFLP [20] and plasmid-pro¢ling techniques [14,21] are considered strain-speci¢c. PCR-RFLP analysis of the 16S2 3S rDNA intergenic spacer region and comparison of partial 16S rDNA sequences allow discrimination between closely related strains of the same species [7,22].…”

Section: Discussionmentioning

confidence: 99%

Emergence of a laccase-positive variant of Azospirillum lipoferum occurs via a two-step phenotypic switching process

Alexandre

1999

FEMS Microbiology Letters

View full text Add to dashboard Cite

Two variants have been isolated from the wild-type Azospirillum lipoferum strain 4B. The first variant, 4V s , spontaneously emerged from the wild-type at frequencies in the order of 10 3R to 10 3Q per cell generation. Compared to the wild-type, the 4V s variant gained (production of a carotenoid-like pigment, assimilation of certain carbohydrates) and lost (swimming motility, reduction of triphenyl tetrazolium chloride, acid production from certain sugars) apparently unrelated phenotypic characteristics. Only from the 4V s variant, a second atypical stable form, variant 4V ss , which acquired laccase activity and ability to produce melanin, appeared under very specific conditions, namely growth at extremely low oxygen concentrations. Neither of the variants was able to revert to the parental phenotype. The results suggest that atypical non-motile laccasepositive isolates of A. lipoferum that are found in the rice rhizosphere originate from wild-type (motile, laccase-negative) cells via a two-step phenotypic switching event, a non-motile laccase-negative variant being an intermediate phase. z 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

show abstract

Section: Discussionmentioning

confidence: 99%

Emergence of a laccase-positive variant of Azospirillum lipoferum occurs via a two-step phenotypic switching process

Alexandre

1999

FEMS Microbiology Letters

View full text Add to dashboard Cite

show abstract

“…Even though no specificity between plant species and bacterial strains has been demonstrated, some affinity exists between bacteria and plant species (Penot et al 1992) or even cultivars (Wani et al 1985). Effects of plant genotype on the interaction with Azospirillum have been demonstrated, for example, for wheat (Triticum aestivum L.) (Kapulnik et al 1987;Caballero-Mellado et al 1992), maize (Zea mays L.) (Garcia de Salamone et al 1996), and pearl millet [Pennisetum americanum (L.) K.…”

Section: Introductionmentioning

confidence: 99%

Inoculation with selected strains of Azospirillum brasilense and A. lipoferum improves yields of maize and wheat in Brazil

et al. 2010

View full text Add to dashboard Cite

Interest in the use of inoculants containing bacteria that promote plant growth is likely to increase in the coming years, due to higher costs of fertilizers, concerns over pollution and emphasis on sustainable agriculture. Although Brazil has a long tradition in research on nitrogen fixation in Azospirillum-grass associations, it has not led to recommendations of strains for use in commercial inoculants. In this study, we report the selection and evaluation of Azospirillum strains for the maize (Zea mays L.) and wheat (Triticum aestivum L.) crops, following protocols established by the Brazilian legislature, i.e. field experiments have to be performed in at least two different localities representing the crop growing regions, and for at least two seasons. In a first set of nine trials performed at Londrina and Ponta Grossa, southern Brazil, nine Azospirillum strains were evaluated after application to seeds as peat-based inoculants. A. brasilense strains Ab-V4, Ab-V5, Ab-V6 and Ab-V7 increased grain yields of maize by 662-823 kg ha −1 , or 24-30%, in relation to non-inoculated controls. Two A. lipoferum strains were tested in two of these experiments and promising results were also obtained. With wheat, A. brasilense strains Ab-V1, Ab-V5, Ab-V6 and Ab-V8 were the most effective, increasing yields by 312-423 kg ha −1 , or 13-18%. In a second trial set with eight field experiments at Londrina an Ponta Grossa, liquid and peat-based inoculants carrying a combination of A. brasilense strains Ab-V5 and Ab-V6 increased maize and wheat yields by 27% and 31%, respectively. Effects of inoculation were attributed to general increases in uptake of several macro and micronutrients and not specifically to biological nitrogen fixation. All experiments received only a low Nfertilizer starter at sowing (24 kg and 20 kg of N ha −1 for the maize and wheat, respectively) and although Plant Soil (2010) 331:413-425

show abstract

“…Despite several reports describing the presence of plasmids in A. brasilense and A. lipoferum (7,19,21,22,31), information about their genome size is imprecise to date. In 1982, Wood et al (31), using a modified Eckhardt electrophoresis method, described the presence of several very large DNA bands with molecular sizes up to 2.8 Mbp that they called minichromosomes, based on their apparent large molecular size.…”

mentioning

confidence: 99%

Genome Structure of the GenusAzospirillum

et al. 2000

View full text Add to dashboard Cite

Azospirillum species are plant-associated diazotrophs of the alpha subclass of Proteobacteria. The genomes of five of the six Azospirillum species were analyzed by pulsed-field gel electrophoresis. All strains possessed several megareplicons, some probably linear, and 16S ribosomal DNA hybridization indicated multiple chromosomes in genomes ranging in size from 4.8 to 9.7 Mbp. The nifHDK operon was identified in the largest replicon.

show abstract

Characterization of Azospirillum associated with maize (Zea mays) in France, using biochemical tests and plasmid profiles

Cited by 18 publications

References 0 publications

Emergence of a laccase-positive variant of Azospirillum lipoferum occurs via a two-step phenotypic switching process

Emergence of a laccase-positive variant of Azospirillum lipoferum occurs via a two-step phenotypic switching process

Inoculation with selected strains of Azospirillum brasilense and A. lipoferum improves yields of maize and wheat in Brazil

Genome Structure of the GenusAzospirillum

Contact Info

Product

Resources

About