Improved methods to detect GTP-binding proteins from plants

Improved methods are described for the detection of G1P-binding proteins (G-proteins) in the protonema of mossFunaria hygrometrica and coleoptiles of corn(Zea mays) and sorghum(Sorghum vulgare). We optimized conditions for the transfer of proteins to nitrocellulose, production of high titer polyclonal anti-Gα (common) antibodies and finally the detection of G-proteins by amplification. In addition to the α-subunit of heterotrimeric G-proteins (M _r 41–43 kDa), a small molecular weight class (< 30 kDa) was also detected by anti-Gα (common) antibodies. An easy, reliable and efficient filter assay is also described to quantify the toxin catalyzed ADP-ribosylation. The apparentK _m of the NAD has been determined to be approximately 1.5μM for the microsomal fraction of moss. Inclusion of G1P stimulated ADP-ribosylation by 2–27-fold. One to three polypeptides representing the α-subunit of heterotrimeric G-proteins of (M_r 37–43 kDa) were ADP-ribosylated in all three plants. The anti-Gβ (C-terminus) antibody cross-reacted strongly with 39 and 34 kDa polypeptide in moss and corn respectively. By employing improved methods two classes of G-proteins have been shown to be present in three plant species.     

Induced systemic resistance (ISR) in plants: mechanism of action

Plants possess a range of active defense apparatuses that can be actively expressed in response to biotic stresses (pathogens and parasites) of various scales (ranging from microscopic viruses to phytophagous insect). The timing of this defense response is critical and reflects on the difference between coping and succumbing to such biotic challenge of necrotizing pathogens/parasites. If defense mechanisms are triggered by a stimulus prior to infection by a plant pathogen, disease can be reduced. Induced resistance is a state of enhanced defensive capacity developed by a plant when appropriately stimulated. Systemic acquired resistance (SAR) and induced systemic resistance (ISR) are two forms of induced resistance wherein plant defenses are preconditioned by prior infection or treatment that results in resistance against subsequent challenge by a pathogen or parasite. Selected strains of plant growth-promoting rhizobacteria (PGPR) suppress diseases by antagonism between the bacteria and soil-borne pathogens as well as by inducing a systemic resistance in plant against both root and foliar pathogens. Rhizobacteria mediated ISR resembles that of pathogen induced SAR in that both types of induced resistance render uninfected plant parts more resistant towards a broad spectrum of plant pathogens. Several rhizobacteria trigger the salicylic acid (SA)-dependent SAR pathway by producing SA at the root surface whereas other rhizobacteria trigger different signaling pathway independent of SA. The existence of SA-independent ISR pathway has been studied in Arabidopsis thaliana, which is dependent on jasmonic acid (JA) and ethylene signaling. Specific Pseudomonas strains induce systemic resistance in viz., carnation, cucumber, radish, tobacco, and Arabidopsis, as evidenced by an enhanced defensive capacity upon challenge inoculation. Combination of ISR and SAR can increase protection against pathogens that are resisted through both pathways besides extended protection to a broader spectrum of pathogens than ISR/SAR alone. Beside Pseudomonas strains, ISR is conducted by Bacillus spp. wherein published results show that several specific strains of species B. amyloliquifaciens, B. subtilis, B. pasteurii, B. cereus, B. pumilus, B. mycoides, and B.sphaericus elicit significant reduction in the incidence or severity of various diseases on a diversity of hosts.     

Molecular cloning of enantioselective ester hydrolase from Bacillus pumilus DBRL-191

A gene from Bacillus pumilus expressed under its native promoter was cloned in Escherichia coli. Recombinant B. pumilus esterase (BPE) affects the kinetic resolution of racemic mixtures such as unsubstituted and substituted 1-(phenyl)ethanols (E approximately 33-103), ethyl 3-hydroxy-3-phenylpropanoate (E approximately 45-71), trans-4-fluorophenyl-3-hydroxymethyl-N-methylpiperidine (E approximately 10-13) and ethyl 2-hydroxy-4-phenylbutyrate (E approximately 7). The enzyme is composed of a 34-amino acid signal peptide and a 181-amino acid mature protein corresponding to a molecular weight of approximately 19.2kD and pI approximately 9.4. 3-D the structural model of the enzyme built by homology modelling using the atomic coordinates from the crystal structure of B. subtilis lipase (LipA) showed a compact minimal alpha/beta hydrolase fold.     

Group B Streptococcus: global incidence and vaccine development

An ongoing public health challenge is to develop vaccines that are effective against infectious diseases that have global relevance. Vaccines against serotypes of group B Streptococcus (GBS) that are prevalent in the United States and Europe are not optimally efficacious against serotypes common to other parts of the world. New technologies and innovative approaches are being used to identify GBS antigens that overcome serotype-specificity and that could form the basis of a globally effective vaccine against this opportunistic pathogen. This Review highlights efforts towards this goal and describes a template that can be followed to develop vaccines against other bacterial pathogens.     

SEAN: SNP prediction and display program utilizing EST sequence clusters

SEAN is an application that predicts single nucleotide polymorphisms (SNPs) using multiple sequence alignments produced from expressed sequence tag (EST) clusters. The algorithm uses rules of sequence identity and SNP abundance to determine the quality of the prediction. A Java viewer is provided to display the EST alignments and predicted SNPs.     

Plant Growth–Promoting Pseudomonas sp. Strains Reduce Natural Occurrence of Anthracnose in Soybean (Glycine max L.) in Central Himalayan Region

Biological control is an accepted important component of current plant disease management strategies. Introduction of bacterized seeds carrying bacterial isolates with proven growth-promotion capabilities and antagonistic characteristics offer a valid alternative to chemical protectants. Root colonization of disease-susceptible (PS 1024) and moderately resistant (PS1042) varieties of soyabean (Glycine Max L) by fluorescent pseudomonad (FLPs) strains GRP₃, PEn-4, PRS₁, and WRS-24 was studied in relation to natural occurrence of anthracnose caused by Colletotrichum dematium (Pers Ex Fr.) Grove. Rhizoplane population of FLPs was maintained at a critical level (5.3 cfu) up to 30 days of plant growth, followed by a steep decline. Indigenous FLPs population, however, remained nearly unchanged (3.0 to 2.4 log g⁻¹ root) between 30 days and 75 days of plant growth. The relative FLPs population in rhizosphere was lower than that in rhizoplane. Although intervarietal difference was observed, the root/shoot length remained unaffected. Compared to nonbacterized control, dry root weight was improved by FLPs treatment. Severity of foliar anthracnose was reduced significantly after FLPs treatment in the variety PS 1042. Because the point of FLPs treatment (seed bacterization) was away from the site of disease appearance (leaf), operation of induced systemic resistance in strains PEn-4 and GRP₃ appears imminent.     

Novel thermostable lipase from <Emphasis Type="Italic">Bacillus circulans</Emphasis> IIIB153: comparison with the mesostable homologue at sequence and structure level

Thermophilic Bacillus circulans IIIB153 isolated from hot springs of North West Himalayas, India, produced an extracellular lipase, which exhibited significant biofilm disruption property on the static biofilm disruption model with a single species of Actinomyces viscosous. The gene encoding the lipase was cloned and overexpressed in Escherichia coli. Recombinant Bacillus circulans lipase (BCL), a monomer with molecular mass of 43 kDa also exhibited significant biofilm disruption activity. The enzyme was optimally active at 60°C, pH 8.5 and retained >70% of its original activity after 1 h incubation at 60°C. 3D structure of BCL developed by homology modeling showed a typical α/β hydrolase fold, a characteristic feature of lipolytic enzymes. Comparison of thermostable BCL with mesostable lipase from Chromobacterium viscosum at the sequence and structure level showed distinct variations in the structural features, with the presence of a high content of proline residues, aromatic amino acids and salt bridges. These features along with the presence of zinc-binding site observed in BCL structure could have a potential role in thermal stability of the enzyme.     

Male Out-Migration: A Factor for the Spread of HIV Infection among Married Men and Women in Rural India

Introduction

Thus far, the reasons for increasing HIV prevalence in northern and eastern Indian states are unknown. We investigated the role of male out-migration in the spread of human immunodeficiency virus (HIV) infection through a case-control study in rural India.

Methods

Currently married men and women were recruited from HIV testing and treatment centers across seven selected districts with high rates of male out-migration in eastern and northern India in 2010 using a case-control study design. Case subjects (men: 595, women: 609) were people who tested HIV seropositive and control subjects (men: 611, women: 600) were those tested HIV seronegative. For each gender, we obtained adjusted odds ratios (AORs) and population attributable risks (PARs) for migration, and behavioral factors.

Results

For men, the prevalence of HIV was significantly higher among those with a migration history (AOR, 4·4); for women, the prevalence of HIV was higher among those with migrant husbands (AOR, 2·3). For both genders, the returned male migration (men: AOR, 3·7; women: AOR, 2·8) was significantly associated with higher prevalence of HIV infection. The PAR associated with male migration was higher for men (54·5%–68·6%) than for women (32·7%–56·9%) across the study areas.

Discussion

Male out-migration is the most important risk factor influencing the spread of HIV infection in rural areas with high out-migration rates, thereby emphasizing the need for interventions, particularly, for returned migrants and spouses of those migrants.     

An Improved Method for In Vitro Large Scale Propagation of Piper betle L

A protocol for large-scale propagation of Piper betle cvs Desawari and Desi Bangla was developed through axillary shoot proliferation. Due to systemic infection as well as high phenol content the crop was very difficult to establish in aseptic condition. But a mixture of 5 mg l^?1 each of chloramphenicol and oxytetracyclin and 100 mg l^?1 each of citric acid and ascorbic acid used in MS medium for 2 days helped in establishment. After 48 h, the explants were transferred to the antibiotic free medium having PVP and ascorbic acid (100 mg l^?1 each), citric acid (50 mg l^?1), and glutathione (20 mg l^?1). Regular subculturing of the explants into liquid medium, use of antioxidants and incubation of the cultures in the dark for initial 7–10 days played a crucial role for keeping them fresh and green. Maximum numbers of axillary shoots were obtained with 2 mg l^?1 BA and 0.2 mg l^?1 NAA as growth supplements. The plants were rooted in 0.25 mg l^?1 IBA and hardened in the soil. Phenolic compound analysis showed almost the same results in tissue-raised and in vivo grown plants in Desawari.