Cooperation involving Plant Growth-Promoting Rhizobacteria results in improvements of plant growth and health. While pathogenic and symbiotic interactions are known to induce transcriptional changes for genes related to plant defense and development, little is known about the impact of phytostimulating rhizobacteria on plant gene expression. This study aims at identifying genes significantly re...

Bacteria of the genus Azospirillum are among the most studied bacteria, stimulating the growth of plants and capable of associative interaction with many higher plants. They have a high adaptive potential to the negative external influences, like the lack of nutrients, salinity, lack of moisture. Compared with other rhizosphere microorganisms, Azospirillum have sufficiently high resistance to h...

Inoculation with Azospirillum brasilense Cd of two leguminous species, soybean (Glycine max) and cowpea (Vigna unguiculata), demonstrated that: (1) A. brasilense significantly increased proton efflux from their roots; (2) inoculation reduced plant membrane potential (in soybean), (3) inoculation changed the phospholipid quantity in plant membranes of calli (in cowpea), and (4) a low molecular w...

The cell-surface charge and cell-surface hydrophobicity of 10 strains of Azospirillum spp. were evaluated by the aqueous, two-polymer phase partitioning assay. Azospirillum spp. had moderate cell-surface hydrophobicity and charge, lower than known values for human pathogens. The hydrophobicity and charge values were higher in solid than in liquid media. A general pattern of modifying hydrophobi...

Six laboratory experiments were carried out to investigate the effect of the fungicide Benomyl on pure cultures of some plant growth promoting bacteria (PGPB) and some fungi. The highest LD50 was recorded for Bacillus circulans and proved to be the most resistant to the fungicide, followed by Azospirillum braziliense, while Penicillium sp. was the most affected microorganism. LD50 values for th...

A new group of nitrogen-fixing Azospirillum sp. bacteria was isolated from the roots of the C4-gramineous plant Miscanthus. Polyphasic taxonomy was performed, including auxanography using API galleries, physiological tests and 16S rRNA sequence comparison. The ability of the isolates to fix dinitrogen was evaluated by amplification of the nifD gene, immunodetection of the dinitrogenase reductas...

The effects of soil moisture on the survival of three diazotrophic bacteria species (Azospirillum amazonense, Gluconacetobacter diazotrophicus and Azospirillum brasilense) were tested. Soil moisture had little influence on the survival of A. brasilense, which is considered a free-living species. On the other hand, increased soil moisture extended the survival of the endophytes A. amazonense and...

Fossil records indicate that life appeared in marine environments ∼3.5 billion years ago (Gyr) and transitioned to terrestrial ecosystems nearly 2.5 Gyr. Sequence analysis suggests that "hydrobacteria" and "terrabacteria" might have diverged as early as 3 Gyr. Bacteria of the genus Azospirillum are associated with roots of terrestrial plants; however, virtually all their close relatives are aqu...

AIMS To investigate the ability of Azospirillum sp., a facultative endophitic diazotrophic bacterium, to release plant growth regulators (PGR) such as polyamines, ethylene, indoleacetic acid and amino acids in both combined-N and N-free cultures. METHODS AND RESULTS The presence of those substances was analysed by HPLC. Azospirillum sp. is capable of releasing PGR and amino acids into the cul...

Rice seedlings were inoculated with Azospirillum sp. B510 and transplanted into a paddy field. Growth in terms of tiller numbers and shoot length was significantly increased by inoculation. Principal-coordinates analysis of rice bacterial communities using the 16S rRNA gene showed no overall change from B510 inoculation. However, the abundance of Veillonellaceae and Aurantimonas significantly i...