Overexpression of NAC gene from Lepidium latifolium L. enhances biomass,shortens life cycle and induces cold stress tolerance in tobacco: potential for engineering fourth generation biofuel crops

We report elevated biomass and altered growth characteristics of tobacco plants up on transformation with a NAC (NAM, ATAF1/2,CUC2) gene (GenBank Accession FJ754254) isolated from Lepidium latifolium L. (LlaNAC). Transgenic plants showed significant differences in fresh weight, midrib length of longest leaf, leaf area, height of the plant, root and shoot weights, etc. during vegetative phase. On 100th day after sowing (DAS), plants of transgenic lines were 2–3 times taller than the wild type plants, though no significant difference was recorded in moisture contents of any of the plant tissues. Over-expression of NAC gene up to 2,000 fold was recorded in leaves of transgenic plants on 100th DAS. Interestingly, transgenic plants showed significantly shortened (P(t) = 0.02–0.04) life cycle, as they showed a completely altered growth behaviour. Transgenic plants entered reproductive phase earlier by 60 days, with lines NC2 and NC7b entering first, followed by line NC10. However, the time period spent in the reproductive phase by the plant was nearly twice in case of transgenic lines NC2, NC7b and NC10, as compared to the wild type plants. Despite that, these lines completed their life cycle in 45–60 days lesser than the time taken by wild-type tobacco plants. No difference was recorded in fruit and seed yield of transgenic or wild type plants. To the best of our knowledge, this is the first report on over-expression of NAC gene causing altered growth and biomass patterns. We expect this study to become an important reference towards future engineering of plants for fuel and fodder purposes.     

Genetic Control of Radiation Sensitivity in SCHIZOSACCHAROMYCES POMBE

Genetic analysis of a large number of radiation-sensitive mutants of S. pombe, isolated in different laboratories, showed that these isolates represent 22 non-allelic loci. The mutants were shown to fall into three distinct classes concerning response to UV and ionizing radiation, including two mutants which are primarily sensitive to ionizing radiation but not to UV. Single-gene mutants were crossed to obtain supersensitive double mutants. Such double mutants showed a marked increase in sensitivty to a variety of inactivating agents as compared to the parental strains. The isolation of three classes of radiation-sensitive mutants and the construction of double mutants implies the presence of multiple pathways in S. pombe for repair of radiation-induced damage. The bearing of these data on cellular repair mechanisms in eukaryotes is discussed.     

Known data on the effectiveness of silver nano particles on root canal disinfection

The goal of endodontic treatment is the debridement and removal of the microbial ecosystem associated with the disease process. The need for root canal disinfectants increases especially in those cases where infection is resistant to the regular treatment and the outcome of endodontic therapy is often compromised. Therefore, it is of interest to document the known effectiveness of silver nanoparticle based root canal disinfectants with other root canal disinfectants on microbial load reduction during root canal disinfection. Known data shows that the overall risk of bias for the selected studies was moderate. Silver nanoparticle based root canal disinfectants showed superior reduction of microbial counts in majority of the studies. This data is limited to vitro studies with no clinical information to validate the use of antimicrobial properties of silver nanoparticles used as root canal disinfectant.     

Tetracycline and Chloramphenicol Efficiency Against Selected Biofilm Forming Bacteria

Despite the constantly increasing need for new antimicrobial agents, antibiotic drug discovery and development seem to have greatly decelerated in recent years. Presented with the significant problem of advancing antimicrobial resistance, the global scientific community has attempted to find alternative solutions; one of the most promising ones is the evaluation and use of old antibiotic compounds. A number of old antibiotic compounds, such as aminoglycosides, chloramphenicol, and tetracycline, are re-emerging as valuable alternatives for the treatment of difficult-to-treat infections. This study examined the in vitro potency for biofilm formation of five isolates (Klebsiella sp., Pseudomonas aeruginosa, Achromobacter sp., Klebsiella pneumoniae, and Bacillus pumilis) and the effects of antibiotics on these biofilms. Furthermore the quantitative analysis of planktonic, loosely attached cells, and their susceptibility to antibiotics was also determined. Twitching motility was observed to determine any effect in the biofilm forming capability of the isolates. All the isolates tested were efficient biofilm-forming strains in the polypropylene and borosilicate test tubes. Standard bacterial enumeration technique and CV staining produced equivalent results both in biofilm and planktonic assays. The biofilm formation of all the strains was affected in the presence of tetracycline or chloramphenicol. Highly significant decrease (P < 0.01) in biofilm formation was observed by treatment with chloramphenicol compared to tetracycline. In addition, the two antibiotics also affected adversely the planktonic and loosely attached cells of all isolates. Thus, testing the effects of older antibiotics on biofilms may supply useful information in addition to standard in vitro testing, particularly in diseases where biofilm formation is involved in the pathogenesis.     

A double-reporter splicing assay for determining splicing efficiency in mammalian cells

Changes in alternative splicing patterns can result from both inherited and acquired defects, and they are increasingly recognized as causes of human diseases. Hence, improvements in the understanding of alternative splicing regulation may provide opportunities for restoring productive patterns of splicing. The identification of factors (such as proteins, nucleic acids or small molecules) that modulate the splicing pattern would be facilitated by systems with which many samples can be screened. The absence of reliable systems prompted us to develop an assay system based on dual enzymatic activities. Two distinct signals derived from spliced and unspliced RNA are measured, providing the basis for a robust, rapid and convenient assay for investigating splicing. This protocol describes how to use this system; the time required for lysing the cells and recording enzymatic activity is about 2 hours.     

Rhizobacterial potential to alter auxin content and growth of <Emphasis Type="Italic">Vigna radiata</Emphasis> (L.)

Potential of non-symbiotic plant growth promoting rhizobacteria (PGPR) to influence the endogenous indole-3-acetic acid (IAA) content and growth of Vigna radiata (L.) was evaluated. The bacterial strains used belonged to Pseudomonas, Escherichia, Micrococcus and Staphylococcus genera. All strains were able to produce IAA (1.16–8.22 μg ml⁻¹) in the presence of 1,000 μg ml⁻¹ of l-tryptophan as revealed by gas chromatography and mass spectrometric (GC–MS) analysis. However, strains exhibited variable results for other growth promoting traits such as phosphate solubilization and siderophore or hydrogen cyanide production. Bacterial IAA production showed significant positive correlation with endogenous IAA content of roots (r = 0.969; P = 0.01) and leaves (r = 0.905; P = 0.01) under axenic conditions. Bacterization of V. radiata seeds significantly enhanced shoot length (up to 48.10%) and shoot fresh biomass (up to 43.80%) under fully axenic conditions. Bacterial strains applied under wire-house conditions also improved shoot length, number of pods, and grain weight up to 58, 65, and 17.15% respectively, over control. Hence, free living (non-symbiotic) PGPR have the ability to influence endogenous IAA content and growth of leguminous plants.     

The Effect of Lactobacillus casei Consumption in Improvement of Obsessive–Compulsive Disorder: an Animal Study

Obsessive–compulsive disorder (OCD) is an important neuropsychiatric disorder worldwide. Common treatments of OCD include serotonergic antidepressants, which can cause potentially serious side effects. We assessed the effects of Lactobacillus casei (L. casei) Shirota consumption in an animal model of OCD. OCD-like symptoms were induced in rats by the chronic injection of the D2/D3 dopamine agonist quinpirole hydrochloride. Rats were classified into five groups of 6 rats. Four groups were injected chronically with quinpirole (0.5 mg/kg, twice weekly for 5 weeks). They were fed with L. casei Shirota (10⁹ CF/g, daily for 4 weeks) (group 1), fluoxetine (10 mg/kg, daily for 4 weeks) (group 2), combination of L. casei Shirota and fluoxetine (group 3), and normal saline (positive control group). The last group did not receive dopamine agonist and was only injected with saline (negative control group). Expression levels of brain-derived neurotrophic factor (Bdnf), solute carrier family 6 member 4 (Slc6a4), and 5-hydroxytryptamine receptor type 2A (Htr2a) were assessed in orbitofrontal cortex tissues of all rats. Behavioral tests showed improvement of OCD signs in rats treated with L. casei Shirota, fluoxetine, and a combination of drugs. Quantitative PCR analysis showed a remarkable decrease in the expression of Bdnf and an increase in the expression of Htr2a in quinpirole-treated rats. After treatment with L. casei Shirota and fluoxetine, the expression level of Bdnf was increased remarkably, whereas Htr2a expression was decreased. The current study showed the effectiveness of L. casei Shirota in the treatment of OCD in a rat model. The beneficial effects of this probiotic are possibly exerted through the modulation of serotonin-related genes expression.