Identification and sequence analysis of putative Sulla species nod factor receptor.

In legumes, LysM domains of receptors-like kinases (RLKs) mediate rhizobial NFs perception; which are required for infection and establishment of symbiosis without triggering the host immune response. In this study, we identify the LysM extracellular domain sequences of putative Sulla species Nod factor receptors (S. pallida, S. capitata and S. coronaria). The Blast search displayed high identity percentages with genes encoding LjNFR5-like of several legumes. Phylogenetic trees were built using the partial nod factor receptor and predicted amino acid sequences, which grouped Sulla in a separate clade. The multiple alignments of the LysM2 domains revealed that amino acids found to be important in other legume species are not conserved in Sulla species. Further examination of the predicted proteins sequences (LysM2 domain) showed that the three species were different in the two crucial sites for Nod factor perception.

Molecular and phenotypic characterization of endophytic bacteria isolated from sulla nodules.

In the current study, bacterial diversity was investigated in root nodules of Sulla pallida and Sulla capitata. The isolates were analyzed on the basis of their phenotypic and molecular characteristics. The phylogenetic analysis based on 16S rRNA and housekeeping genes (recA and atpD) showed that the isolated bacteria related to Sinorhizobium, Neorhizobium, Phyllobacterium, Arthrobacter, Variovorax and Pseudomonas genera. This is the first report of Neorhizobium genus associated with Hedysarum genus. Phenotypically, all strains tolerate the elevated temperature of 40 °C, and salt stress at a concentration of 2%. In addition, the isolates failed to induce nodulation on their original host; and the symbiotic genes could not be amplified, suggesting that these strains are endophytic bacteria.

Unraveling the expression of genes involved in the biosynthesis pathway of cardiolipin and phosphatidylethanolamine in Salmonella Hadar grown under static magnetic field 200 mT.

We aimed in this work to evaluate the effect of static magnetic field 200 mT (SMF) on the expression of genes involved in the biosynthetic pathway of cardiolipin: g3pd, plsB, cdsA, pgsA, pgpA, cls and phosphatidylethanolamine: pssA and psd in Salmonella enterica subsp enterica serovar Hadar. Bacteria were exposed to a SMF during 3, 6 and 9 h. RNA extraction was followed by Reverse Transcriptase Polymerase Chain Reaction RT-PCR. The relative quantification of mRNA expression levels using 16S rRNA doesn't change during the time exposure. RT-PCR was done for two exposure experiments. The gene expression using RT-PCR present no significant difference in case of plsB, cdsA, pgpA, pgsA and psd genes during the different exposure times. However, a significant increase was observed in the expression of g3pd and pssA genes after 6 h and for cls gene after 3 h of exposure, but any variation was notified after 9 h of exposure. So we can conclude from this study that cls, g3pd and pssA genes are required in the adaptation of Salmonella Hadar to SMF.

Prevention of H2O2 Induced Oxidative Damages of Rat Testis by Thymus algeriensis.

OBJECTIVE: We evaluate the effects of Thymus algeriensis (TEO) against hydrogen peroxide (H2O2) toxicity on body and testis weight, testis sperm count, testis lipid peroxidation, and antioxidant enzyme activities in rats. METHODS: Rats were treated with low (LD) and high dose (HD) of H2O2 (0.1 and 1 mmol/L) in the presence or absence of TEO (150 mg/kg). RESULTS: The results exhibited a significant decrease in body weight and testis weight, in total sperm number decrease (P<0.05), sperm motility and percentage of sperm viability, leading to complete arrest, in sperm flagellar beat frequency by the gavage of 1 mmol/L H2O2 compared to controls. The administration of H2O2 resulted in a significant reduction in testis GSH, GPx, CAT, SOD, and GST activity and significant increase (P<0.05) in MDA concentration compared with the untreated control animals. TEO pre-treatment protected testis from the H2O2 generated oxidative stress. These results were confirmed by histological architecture examinations. CONCLUSION: H2O2 has the ability to alter the sperm function, characteristics and development of testis. However, TEO is an efficient natural agent, which can prevent the testis from H2O2-induced oxidative damage in rats.

Molecular phylogenetic analysis of Rhizobium sullae isolated from Algerian Hedysarum flexuosum.

Isolates from root nodules of Hedysarum flexuosum, sampled from north region of Algeria, were analyzed on the basis of their phenotypic and molecular characteristics. They were tested for their tolerance to NaCl, pH, temperatures, antibiotics and heavy metals resistance. Interestingly, the isolate Hf_04N appeared resistant to ZnCl2 (50 µg/mL) and grew at high saline concentration up to 9 %. The phylogenetic positions of five isolates were studied by comparative sequence analysis of 16S rRNA, recA, nifH and nodD genes. There were grouped close to the Rhizobium sullae type strain in relation to their 16S rRNA, recA and nifH genes-based phylogenies. By contrast, the tree of nodD gene was not congruent with ribosomal, housekeeping and nitrogen fixation genes. We suggest that our strains have a novel nodD gene. The detection of conserved domains of NodD protein and nitrogenase reductase enzyme, confirm their ability to nodulate and fix nitrogen.