Impact of two sp. on the response of diverse genotypes under salt stress.

Unlabelled: Currently, salinization is impacting more than 50% of arable land, posing a significant challenge to agriculture globally. Salt causes osmotic and ionic stress, determining cell dehydration, ion homeostasis, and metabolic process alteration, thus negatively influencing plant development. A promising sustainable approach to improve plant tolerance to salinity is the use of plant growth-promoting bacteria (PGPB).

sp. nov., a new nitrogen-fixing symbiovar isolated from root nodules of in Tunisia.

Three bacterial strains, 1AS11, 1AS12 and 1AS13, members of the new symbiovar salignae and isolated from root nodules of grown in Tunisia, were characterized using a polyphasic approach. All three strains were assigned to the complex on the basis of gene analysis. Phylogenetic analysis based on 1734 nucleotides of four concatenated housekeeping genes (, , and ) showed that the three strains were distinct from known rhizobia species of the complex and clustered as a separate clade within this complex.

Different species of Bradyrhizobium from symbiovars genistearum and retamae nodulate the endemic Retama dasycarpa in the High Atlas Mountains.

Retama dasycarpa is an endemic Retama species native to the cold semi-arid bioclimates of the High Atlas Mountains in Morocco. In this work, we analyzed the diversity of the microsymbionts nodulating this plant and their different phenotypic and symbiotic characteristics. Phylogenetic analysis of the 16S rRNA gene revealed that the tested isolates clustered in the Bradyrhizobium genus.

Chemical Composition and Antimicrobial Activity of Essential Oils from Three Mediterranean Plants against Eighteen Pathogenic Bacteria and Fungi.

The chemical composition and antimicrobial activity of essential oils (EOs) obtained from three medicinal plants of the Moroccan flora were evaluated. The chemical composition of EOs of , and was determined using a gas chromatograph coupled with mass spectrometry. Carvacrol (75.

Salt stress mitigation in by combining different microbial inocula.

Unlabelled: Arid and semi-arid areas are considered vulnerable to various environmental constraints which are further fortified by climate change. Salinity is one of the most serious abiotic factors affecting crop yield and soil fertility. Till now, no information is available on the effect of salinity on development and symbiotic nitrogen (N) fixation in the legume species .

Genotypic and symbiotic diversity studies of rhizobia nodulating Acacia saligna in Tunisia reveal two novel symbiovars within the Rhizobium leguminosarum complex and Bradyrhizobium.

Acacia saligna is an invasive alien species that has the ability to establish symbiotic relationships with rhizobia. In the present study, genotypic and symbiotic diversity of native rhizobia associated with A. saligna in Tunisia were studied.

Application of Native or Exotic Arbuscular Mycorrhizal Fungi Complexes and Monospecific Isolates from Saline Semi-Arid Mediterranean Ecosystems Improved 's Growth and Mitigated Salt Stress Negative Effects.

The date, the palm tree ( L.) is an important component of arid and semi-arid Mediterranean ecosystems, particularly in Morocco where it plays a considerable socio-economic and ecological role. This species is largely affected by desertification, global warming, and anthropic pressure.

Genotypic and symbiotic diversity of native rhizobia nodulating red pea (Lathyrus cicera L.) in Tunisia.

Nodulation and genetic diversity of native rhizobia nodulating Lathyrus cicera plants grown in 24 cultivated and marginal soils collected from northern and central Tunisia were studied. L. cicera plants were nodulated and showed the presence of native rhizobia in 21 soils.

Isolation of a chitinolytic Bacillus licheniformis S213 strain exerting a biological control against Phoma medicaginis infection.

Among nine chitinase-producing strains isolated from Tunisian soil, one isolate called S213 exhibited a potent chitinolytic activity. S213 strain was identified as Bacillus licheniformis by API 50CH system and sequence analysis of its partial 16S ribosomal DNA. Chitinolytic activity was induced either by colloidal chitin or fungal cell walls, and the highest chitinase activity reached at the late stationary phase exhibiting optimal temperature and pH of 50-60 °C and pH 6.

Rhizobium azibense sp. nov., a nitrogen fixing bacterium isolated from root-nodules of Phaseolus vulgaris.

Three microbial strains isolated from common beans, 23C2T (Tunisia), Gr42 (Spain) and IE4868 (Mexico), which have been identified previously as representing a genomic group closely related to Rhizobium gallicum, are further studied here. Their 16S rRNA genes showed 98.5-99% similarity with Rhizobium loessense CCBAU 7190BT, R.

Sinorhizobium americanum symbiovar mediterranense is a predominant symbiont that nodulates and fixes nitrogen with common bean (Phaseolus vulgaris L.) in a Northern Tunisian field.

A total of 40 symbiotic bacterial strains isolated from root nodules of common bean grown in a soil located in the north of Tunisia were characterized by PCR-RFLP of the 16S rRNA genes. Six different ribotypes were revealed. Nine representative isolates were submitted to phylogenetic analyses of rrs, recA, atpD, dnaK, nifH and nodA genes.

Diversity of nodule-endophytic agrobacteria-like strains associated with different grain legumes in Tunisia.

This study represents the first report describing the genetic diversity of nodule-endophytic agrobacteria isolated from diverse legumes and their phylogenetic relationships with the valid species of agrobacteria, as well as the non-recognized genomospecies of the former Agrobacterium tumefaciens (Rhizobium radiobacter). The genetic diversity of a collection of 18 non-nodulating agrobacteria-like strains, previously isolated from root nodules of Vicia faba, Cicer arietinum and Phaseolus vulgaris from different geographical regions of Tunisia, was studied by REP-PCR and PCR-RFLP of the 16S-23S rDNA IGS, as well as by sequence analysis of the 16S rDNA and the housekeeping genes recA and atpD. The aim of the work was to study the genetic diversity of the different isolates and to check for any host-specificity.

Symbiotic diversity of Ensifer meliloti strains recovered from various legume species in Tunisia.

Ensifer meliloti (formerly Sinorhizobium meliloti) was first considered as a specific microsymbiont of Medicago, Melilotus and Trigonella. However, strains of E. meliloti were recovered from root nodules of various legume species and their symbiotic status still remains unclear.

Salt-tolerant rhizobia isolated from a Tunisian oasis that are highly effective for symbiotic N2-fixation with Phaseolus vulgaris constitute a novel biovar (bv. mediterranense) of Sinorhizobium meliloti.

Nodulation of common bean was explored in six oases in the south of Tunisia. Nineteen isolates were characterized by PCR-RFLP of 16S rDNA. Three species of rhizobia were identified, Rhizobium etli, Rhizobium gallicum and Sinorhizobium meliloti.

Agrobacterium strains isolated from root nodules of common bean specifically reduce nodulation by Rhizobium gallicum.

In a previous work, we showed that non-nodulating agrobacteria strains were able to colonize root nodules of common bean. Both rhizobia and agrobacteria co-existed in the infected nodules. No impact on symbiosis was found in laboratory conditions when using sterile gravel as a support for growth.