The effect of exogenous and endogenous phytohormones on the in vitro development of gametophyte and sporophyte in <Emphasis Type="Italic">Asplenium nidus</Emphasis> L.

The fern Asplenium nidus L. is in great demand as an ornamental plant. The aim of this work was to investigate the influence of phytohormones in promoting a gametophytic and sporophytic growth in homogenized sporophytes tissue. Exogenous application of 0.5 and 5 μM N ⁶-benzyladenine, 0.05 and 0.5 μM indole-3-acetic acid (IAA), and 0.3 and 3 μM gibberellic acid (GA₃) favoured sporophyte regeneration, whereas gametophyte regeneration took place when plant material was cultured in a hormone-free liquid MS medium. The endogenous contents of the auxin IAA, the cytokinins trans-zeatin, trans-zeatin riboside, dihydrozeatin, dihydrozeatin riboside, isopentenyladenine and isopentenyladenosine, and the gibberellins GA₁, GA₃, GA₄, GA₇, GA₉ and GA₂₀ in growing gametophytes and sporophytes were evaluated. Similar levels of the auxin and cytokinins and qualitative differences in the gibberellins were found between both generations.     

Impact of Parthenium hysterophorus L. invasion on plant species composition and soil properties of grassland communities in Nepal

Parthenium hysterophorus (Asteraceae) is a noxious plant that is considered one of the most invasive species in the world. We studied changes in the composition of plant species and soil properties related to the invasion of P. hysterophorus in three grassland communities of central Nepal. We collected vegetation and soil data along transects that were established in densely invaded to non-invaded areas within homogenous grassland stands. We found significant differences between invaded, transitional and non-invaded plots in species composition and soil properties. There were fewer species in non-invaded than transitional and invaded plots. By P. hysterophorus invasion both native and non-native species were supported or replaced, respectively. The concentrations of soil nitrogen and organic matter were significantly higher in transitional and invaded plots than in non-invaded plots. Soil pH, phosphorus and potassium were highest in the invaded plots, lowest in the non-invaded and intermediate in the transitional plots. Due to changes in above-ground vegetation and below-ground soil nutrient contents, P. hysterophorus invasion is likely to have an overall negative effect on the functioning of the entire ecosystem. Therefore, management of noxious P. hysterophorus is necessary to prevent future problems.     

Mobilizing metaphors: the popular use of keystone,flagship and umbrella species concepts

Misrepresentation of terminology is a major impediment for attempts at enhancing public conservation literacy. Despite being critically important for improving conservation practice, there have been few systematic analyses of the popular use of conservation terminology. This paper draws from science communication studies and metaphor analysis, to examine how keystone, flagship and umbrella species concepts are used and represented in non-academic contexts. 557 news articles containing these terms were systematically analyzed. Mammals featured in 60% of articles on keystones, 55% on flagships and 63% on umbrella species. Number of articles explaining the terms keystone (35%) and flagship (31%) was low, and keystones were the most misrepresented term. Keystones were metaphorically linked with balance, flagships with representation and umbrella species with protection. These metaphors influenced public interpretation of scientific terminology, oriented actions towards select species, and led to a valuation of such actions. Together, the findings highlight three important aspects of popular use of conservation terminology: (1) communication is largely biased towards mammals, (2) everyday language plays a vital role in the interpretation of concepts, and (3) metaphors influence peoples’ actions and understanding. Conservation biologists need to engage with issues of language if public conservation literacy is to be improved. Further evaluations of concepts with high public and policy relevance, systematic identification of communication shortfalls, and linguistic assessments prior to promoting new terms are potential ways of achieving this.     

Lactosylceramide synthase β-1,4-GalT-V: A novel target for the diagnosis and therapy of human colorectal cancer

Little is known about an oncogenic signal transducer β-1,4-galactosyltransferase-V (β-1,4-GalT-V), in human colorectal cancer. Using quantitative RT-PCR, immunohistochemical staining and ELISA assays, we determined that β-1,4-GalT-V gene/protein expression is specifically increased in human colorectal cancer (CRC) tumors, compared to visibly normal tissue. Furthermore, we observed a marked increase in its enzymatic activity, and its product lactosylceramide. Moreover, we found increased dihydrosphingolipid metabolites, in particular dihydrosphingomyelin in cancer tissue compared to normal. Further, inhibition of glycosphingolipid synthesis by the synthetic ceramide analog, D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), concurrently inhibited colorectal cancer cell (HCT-116) proliferation, as well as β-1,4-GalT-V mass and several glycosphingolipid levels. We conclude that β-1,4-GalT-V may serve as a diagnostic and therapeutic biomarker for the progression of human colorectal cancer, and consequently, inhibition of GSL synthesis may be a novel approach for the treatment of this life-threatening disease.     

Rbf Activates the Myogenic Transcriptional Program to Promote Skeletal Muscle Differentiation

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Gene expression profiling of candidate virulence factors in the laminated root rot pathogen Phellinus sulphurascens

Background

Phellinus sulphurascens is a fungal pathogen that causes laminar root rot in conifers, one of the most damaging root diseases in western North America. Despite its importance as a forest pathogen, this fungus is still poorly studied at the genomic level. An understanding of the molecular events involved in establishment of the disease should help to develop new methods for control of this disease.

Results

We generated over 4600 expressed sequence tags from two cDNA libraries constructed using either mycelia grown on cellophane sheets and exposed to Douglas-fir roots or tissues from P. sulphurascens-infected Douglas-fir roots. A total of 890 unique genes were identified from the two libraries, and functional classification of 636 of these genes was possible using the Functional Catalogue (FunCat) annotation scheme. cDNAs were identified that encoded 79 potential virulence factors, including numerous genes implicated in virulence in a variety of phytopathogenic fungi. Many of these putative virulence factors were also among 82 genes identified as encoding putatively secreted proteins. The expression patterns of 86 selected fungal genes over 7 days of infection of Douglas-fir were examined using real-time PCR, and those significantly up-regulated included rhamnogalacturonan acetylesterase, 1,4-benzoquinone reductase, a cyclophilin, a glucoamylase, 3 hydrophobins, a lipase, a serine carboxypeptidase, a putative Ran-binding protein, and two unknown putatively secreted proteins called 1 J04 and 2 J12. Significantly down-regulated genes included a manganese-superoxide dismutase, two metalloproteases, and an unknown putatively secreted protein called Ps0058.

Conclusions

This first collection of Phellinus sulphurascens EST sequences and its annotation provide an important resource for future research aimed at understanding key virulence factors of this forest pathogen. We examined the expression patterns of numerous fungal genes with potential roles in virulence, and found a collection of functionally diverse genes that are significantly up- or down-regulated during infection of Douglas-fir seedling roots by P. sulphurascens.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-603) contains supplementary material, which is available to authorized users.     

Determinants of Public Attitudes to Genetically Modified Salmon

The objective of this paper is to assess the attitude of Malaysian stakeholders to genetically modified (GM) salmon and to identify the factors that influence their acceptance of GM salmon using a structural equation model. A survey was carried out on 434 representatives from various stakeholder groups in the Klang Valley region of Malaysia. Public attitude towards GM salmon was measured using self-developed questionnaires with seven-point Likert scales. The findings of this study have confirmed that public attitudes towards GM salmon is a complex issue and should be seen as a multi-faceted process. The most important direct predictors for the encouragement of GM salmon are the specific application-linked perceptions about religious acceptability of GM salmon followed by perceived risks and benefits, familiarity, and general promise of modern biotechnology. Encouragement of GM salmon also involves the interplay among other factors such as general concerns of biotechnology, threatening the natural order of things, the need for labeling, the need for patenting, confidence in regulation, and societal values. The research findings can serve as a database that will be useful for understanding the social construct of public attitude towards GM foods in a developing country.     

Development of Multidrug Resistant Tuberculosis in Bangladesh: A Case-Control Study on Risk Factors

Objective

To determine the risk factors for developing multidrug resistant tuberculosis in Bangladesh.

Methods

This case-control study was set in central, district and sub-district level hospitals of rural and urban Bangladesh. Included were 250 multidrug resistant tuberculosis (MDR-TB) patients as cases and 750 drug susceptible tuberculosis patients as controls. We recruited cases from all three government hospitals treating MDR-TB in Bangladesh during the study period. Controls were selected randomly from those local treatment units that had referred the cases. Information was collected through face-to-face interviews and record reviews. Unadjusted and multivariable logistic regression were used to analyse the data.

Results

Previous treatment history was shown to be the major contributing factor to MDR-TB in univariate analysis. After adjusting for other factors in multivariable analysis, age group “18–25” (OR 1.77, CI 1.07–2.93) and “26–45” (OR 1.72, CI 1.12–2.66), some level of education (OR 1.94, CI 1.32–2.85), service and business as occupation (OR 2.88, CI 1.29–6.44; OR 3.71, CI 1.59–8.66, respectively), smoking history (OR 1.58, CI 0.99–2.5), and type 2 diabetes (OR 2.56 CI 1.51–4.34) were associated with MDR-TB. Previous treatment was not included in the multivariable analysis as it was correlated with multiple predictors.

Conclusion

Previous tuberculosis treatment was found to be the major risk factor for MDR-TB. This study also identified age 18 to 45 years, some education up to secondary level, service and business as occupation, past smoking status, and type 2 diabetes as comorbid illness as risk factors. National Tuberculosis programme should address these risk factors in MDR-TB control strategy. The integration of MDR-TB control activities with diabetes and tobacco control programmes is needed in Bangladesh.