A simple, quantitative experimental model, offering a convenient and basic approach to studies of plant-bacterium interactions, is proposed. This involves immobilizing a unicellular, freshwater microalga, a Chlorella species, serving as the plant, with a plant growth-promoting bacterium, an Azospirillum species, in small alginate beads to allow close interaction and to avoid external interferen...

The N2 fixing bacteria Klebsiella pneumoniae, Azospirillum brasilense, Rhodopseudomonas sphaeroides and Rhodospirillum rubrum, but not Azotobacter vinelandii accumulate the glutamine analogue methionine sulfoximine in the cell. In the accumulating cells methionine sulfoximine inhibits ammonium transport. Accumulation and inhibition are prevented by glutamine.

Sequencing the glnA genes of two chemically induced Azospirillum brasilense glutamine synthetase mutants revealed an Arg-->Cys mutation, corresponding to the glutamate binding site, in one mutant and an Asp-->Asn mutation, corresponding to the ammonium binding site, in the second mutant. The phenotypic changes in these mutants are discussed in relation to their genotypes.

Genetic data suggest that the oligotrophic freshwater bacterium Caulobacter crescentus metabolizes D-xylose through a pathway yielding alpha-ketoglutarate, comparable to the recently described L-arabinose degradation pathway of Azospirillum brasilense. Enzymes of the C. crescentus pathway, including an NAD(+)-dependent xylose dehydrogenase, are encoded in the xylose-inducible xylXABCD operon (C...

A field study was conducted to compare the formationand bacterial communities of rhizosheaths of wheat grown under wheat-cotton and wheat-rice rotation and to study the effects of bacterial inoculation on plant growth. Inoculation of Azospirillum sp. WS-1 and Bacillus sp. T-34 to wheat plants increased root length, root and shoot dry weight and dry weight of rhizosheathsoil when compared to non...

recently, using the source of organic fertilizers and biofertilizers in sustainable crop production is growing. in order to evaluate the effect of organic compounds, biofertilizers and chemical fertilizer on morphological properties, yield and yield components of forage sorghum (sorghum bicolor) a field experiment was conducted in the research farm, college of agriculture, ferdowsi university o...

bacteria of the genus azospirillum are well known as plant growth promoting rhizobacteria. the ability to synthesize phytohormones is considered one of the most important mechanisms to promote plant growth and is widely distributed among plant-associated rhizobacteria.the most important phytohormone produced by azospirillum is the auxin indole-3-acetic acid, with the l-tryptophan as the precurs...

soil and water salinity are amongst the severe and progressive problems worldwide which affects most cropland areas of iran. using endophytic microorganisms (which are amongst the most important soil microorganisms) to alleviate the detrimental effect of environmental stresses such as salinity is recently globally considered. in order to test the effects of azospirillum strains and fungus pirif...

in order to study the consequences of the application of mycorrhiza and azospirillum inoculants on yield and yield components of wheat cultivars, an experiment was conducted in the research station of shahid chamran university of ahvaz, iran in 2012-13. the experimental design was factorial based on randomized complete blocks design with three replications. the treatments including of mycorrhiz...