Genome sequence of Ensifer meliloti strain WSM1022; a highly effective microsymbiont of the model legume Medicago truncatula A17

Ensifer meliloti WSM1022 is an aerobic, motile, Gram-negative, non-spore-forming rod that can exist as a soil saprophyte or as a legume microsymbiont of Medicago. WSM1022 was isolated in 1987 from a nodule recovered from the roots of the annual Medicago orbicularis growing on the Cyclades Island of Naxos in Greece. WSM1022 is highly effective at fixing nitrogen with M. truncatula and other annual species such as M. tornata and M. littoralis and is also highly effective with the perennial M. sativa (alfalfa or lucerne). In common with other characterized E. meliloti strains, WSM1022 will nodulate but fixes poorly with M. polymorpha and M. sphaerocarpos and does not nodulate M. murex. Here we describe the features of E. meliloti WSM1022, together with genome sequence information and its annotation. The 6,649,661 bp high-quality-draft genome is arranged into 121 scaffolds of 125 contigs containing 6,323 protein-coding genes and 75 RNA-only encoding genes, and is one of 100 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) project.     

Highly Specific Culture-Independent Detection of YGNGV Motif-Containing Pediocin-Producing Strains

A novel method based on (1) initial microbiological screening and (2) a highly specific PCR is described for selection of strains expressing YGNGV motif-containing pediocin. Initial screening is carried out using spot on the lawn assay for selection of acid-free, hydrogen peroxide (H₂O₂)-free and secreted heat-stable inhibitory activity producing strains. This is followed by highly specific PCR for amplification of 406-bp fragment using forward primer: 5′-tggccaatatcattggtggt-3′ targeting signal peptide sequence of pediocin structural gene and reverse primer: 5′-ctactaacgcttggctggca-3′ encoding N-terminus of immunity gene. The assay was validated with Pediococcus pentosaceus NCDC273 and Pediococcus acidilactici NCDC252 using (1) digestion of amplified 406-bp fragment with HindIII restriction enzyme-producing two restriction fragments of expected sizes (227 and 179 bp), (2) nucleotide sequencing of 406-bp fragment from both strains found these pediocins identical to pediocin PA-1/AcH and (3) identification of both pediocins as pediocin PA-1 at protein level using RP-HPLC. The assay was used for screening six strains (3 pediococci, 2 lactobacilli and an Enterococcus faecium) producing acid-free, hydrogen peroxide (H₂O₂)-free and secreted heat-stable inhibitory activity. This resulted in the detection of three new strains (P. pentosaceus NCDC35, E. faecium NCDC124 and Lactobacillus plantarum NCDC20) producing YGNGV motif-containing pediocins.     

The C. elegans Male Exercises Directional Control during Mating through Cholinergic Regulation of Sex-Shared Command Interneurons

Background

Mating behaviors in simple invertebrate model organisms represent tractable paradigms for understanding the neural bases of sex-specific behaviors, decision-making and sensorimotor integration. However, there are few examples where such neural circuits have been defined at high resolution or interrogated.

Methodology/Principal Findings

Here we exploit the simplicity of the nematode Caenorhabditis elegans to define the neural circuits underlying the male’s decision to initiate mating in response to contact with a mate. Mate contact is sensed by male-specific sensilla of the tail, the rays, which subsequently induce and guide a contact-based search of the hermaphrodite’s surface for the vulva (the vulva search). Atypically, search locomotion has a backward directional bias so its implementation requires overcoming an intrinsic bias for forward movement, set by activity of the sex-shared locomotory system. Using optogenetics, cell-specific ablation- and mutant behavioral analyses, we show that the male makes this shift by manipulating the activity of command cells within this sex-shared locomotory system. The rays control the command interneurons through the male-specific, decision-making interneuron PVY and its auxiliary cell PVX. Unlike many sex-shared pathways, PVY/PVX regulate the command cells via cholinergic, rather than glutamatergic transmission, a feature that likely contributes to response specificity and coordinates directional movement with other cholinergic-dependent motor behaviors of the mating sequence. PVY/PVX preferentially activate the backward, and not forward, command cells because of a bias in synaptic inputs and the distribution of key cholinergic receptors (encoded by the genes acr-18, acr-16 and unc-29) in favor of the backward command cells.

Conclusion/Significance

Our interrogation of male neural circuits reveals that a sex-specific response to the opposite sex is conferred by a male-specific pathway that renders subordinate, sex-shared motor programs responsive to mate cues. Circuit modifications of these types may make prominent contributions to natural variations in behavior that ultimately bring about speciation.     

Ligand-Induced Protein Mobility in Complexes of Carbonic Anhydrase II and Benzenesulfonamides with Oligoglycine Chains

This paper describes a biophysical investigation of residual mobility in complexes of bovine carbonic anhydrase II (BCA) and para-substituted benzenesulfonamide ligands with chains of 1–5 glycine subunits, and explains the previously observed increase in entropy of binding with chain length. The reported results represent the first experimental demonstration that BCA is not the rigid, static globulin that has been typically assumed, but experiences structural fluctuations upon binding ligands. NMR studies with ¹⁵N-labeled ligands demonstrated that the first glycine subunit of the chain binds without stabilization or destabilization by the more distal subunits, and suggested that the other glycine subunits of the chain behave similarly. These data suggest that a model based on ligand mobility in the complex cannot explain the thermodynamic data. Hydrogen/deuterium exchange studies provided a global estimate of protein mobility and revealed that the number of exchanged hydrogens of BCA was higher when the protein was bound to a ligand with five glycine subunits than when bound to a ligand with only one subunit, and suggested a trend of increasing number of exchanged hydrogens with increasing chain length of the BCA-bound ligand, across the series. These data support the idea that the glycine chain destabilizes the structure of BCA in a length-dependent manner, causing an increase in BCA mobility. This study highlights the need to consider ligand-induced mobility of even “static” proteins in studies of protein-ligand binding, including rational ligand design approaches.     

Association between Gender,Process of Care Measures,and Outcomes in ACS in India: Results from the Detection and Management of Coronary Heart Disease (DEMAT) Registry

Background

Studies from high-income countries have shown that women receive less aggressive diagnostics and treatment than men in acute coronary syndromes (ACS), though their short-term mortality does not appear to differ from men. Data on gender differences in ACS presentation, management, and outcomes are sparse in India.

Methods and Results

The Detection and Management of Coronary Heart Disease (DEMAT) Registry collected data from 1,565 suspected ACS patients (334 women; 1,231 men) from ten tertiary care centers throughout India between 2007–2008. We evaluated gender differences in presentation, in-hospital and discharge management, and 30-day death and major adverse cardiovascular event (MACE; death, re-hospitalization, and cardiac arrest) rates. Women were less likely to present with STEMI than men (38% vs. 55%, p<0.001). Overall inpatient diagnostics and treatment patterns were similar between men and women after adjustment for potential confounders. Optimal discharge management with aspirin, clopidogrel, beta-blockers, and statin therapy was lower for women than men, (58% vs. 65%, p = 0.03), but these differences were attenuated after adjustment (OR = 0.86 (0.62, 1.19)). Neither the outcome of 30-day mortality (OR = 1.40 (0.62, 3.16)) nor MACE (OR = 1.00 (0.67, 1.48)) differed significantly between men and women after adjustment.

Conclusions

ACS in-hospital management, discharge management, and 30-day outcomes did not significantly differ between genders in the DEMAT registry, though consistently higher treatment rates and lower event rates in men compared to women were seen. These findings underscore the importance of further investigation of gender differences in cardiovascular care in India.     

NO and ROS implications in the organization of root system architecture

Over the past decades the role of nitric oxide (NO) and reactive oxygen species (ROS) in signaling and cellular responses to stress has witnessed an exponential trend line. Despite advances in the subject, our knowledge of the role of NO and ROS as regulators of stress and plant growth and their implication in signaling pathways is still partial. The crosstalk between NO and ROS during root formation offers new domains to be explored, as it regulates several plant functions. Previous findings indicate that plants utilize these signaling molecules for regulating physiological responses and development. Depending upon cellular concentration, NO either can stimulate or impede root system architecture (RSA) by modulating enzymes through post-translational modifications. Similarly, the ROS signaling molecule network, in association with other hormonal signaling pathways, control the RSA. The spatial regulation of ROS controls cell growth and ROS determine primary root and act in concert with NO to promote lateral root primordia. NO and ROS are two central messenger molecules which act differentially to upregulate or downregulate the expression of genes pertaining to auxin synthesis and to the configuration of root architecture. The investigation concerning the contribution of donors and inhibitors of NO and ROS can further aid in deciphering their role in root development. With this background, this review provides comprehensive details about the effect and function of NO and ROS in the development of RSA.     

Conservation Strategy for African Medicinal Species: <i>In Vitro</i> Biotechnological Approach

The use of medicinal plants for different therapeutic values is well documented in African continent. African diverse biodiversity hotspots provide a wide range of endemic species, which ensures a potential medicinal value. The feasible conservation approach and sustainable harvesting for the medicinal species remains a huge challenge. However, conservation approach through different biotechnological tools such as micropropagation, somatic embryogenesis, synthetic seed production, hairy root culture, molecular markers based study and cryopreservation of endemic African medicinal species is much crucial. In this review, an attempt has been made to provide different in vitro biotechnological approaches for the conservation of African medicinal species. The present review will be helpful in further technology development and deciding the priorities at decision-making levels for in vitro conservation and sustainable use of African medicinal species.     

Virtual high-throughput screening of natural compounds in-search of potential inhibitors for protection of telomeres 1 (POT1)

Communicated by Ramaswamy H. Sarma     

Effect of nitric oxide signaling in bacterial-treated soybean plant under salt stress

To understand protective roles of nitric oxide against salt stress, the effects of exogenous sodium nitroprusside on activities of lipoxygenase, peroxidase, phenylalanine ammonialyase, catalase, superoxide dismutase enzymes, proline accumulation, and distribution of sodium in soybean plants under salt were determined. Application of sodium nitroprusside + bacterium enhanced plant growth-promotion characteristics, activities of different enzymes, and proline accumulation in the presence of sodium nitroprusside under salt stress. Treatment with NaCl at 200 mM and sodium nitroprusside (0.1 mM) reduced Na⁺ levels but increased K⁺ levels in leaves in comparison with the NaCl-treated plants. Correspondingly, the plants treated with exogenous sodium nitroprusside and NaCl maintained a lower ratio of [Na⁺]/[K⁺] in NaCl-stressed plants.