Arabidopsis nonhost resistance gene PSS1 confers immunity against an oomycete and a fungal pathogen but not a bacterial pathogen that cause diseases in soybean

ABSTRACT: BACKGROUND: Nonhost resistance (NHR) provides immunity to all members of a plant species against all isolates of a microorganism that is pathogenic to other plant species. Three Arabidopsis thaliana PEN (penetration deficient) genes, PEN1, 2 and 3 have been shown to provide NHR against the barley pathogen Blumeria graminis f. sp. hordei at the prehaustorial level. Arabidopsis pen1-1 mutant lacking the PEN1 gene is penetrated by the hemibiotrophic oomycete pathogen Phytophthora sojae, the causal organism of the root and stem rot disease in soybean. We investigated if there is any novel nonhost resistance mechanism in Arabidopsis against the soybean pathogen, P. sojae. RESULTS: The P. sojae susceptible (pss) 1 mutant was identified by screening a mutant population created in the Arabidopsis pen1-1 mutant that lacks penetration resistance against the non adapted barley biotrophic fungal pathogen, Blumeria graminis f. sp. hordei. Segregation data suggested that PEN1 is not epistatic to PSS1. Responses of pss1 and pen1-1 to P. sojae invasion were distinct and suggest that PSS1 may act at both pre- and post-haustorial levels, while PEN1 acts at the pre-haustorial level against this soybean pathogen. Therefore, PSS1 encodes a new form of nonhost resistance. The pss1 mutant is also infected by the necrotrophic fungal pathogen, Fusarium virguliforme, which causes sudden death syndrome in soybean. Thus, a common NHR mechanism is operative in Arabidopsis against both hemibiotrophic oomycetes and necrotrophic fungal pathogens that are pathogenic to soybean. However, PSS1 does not play any role in immunity against the bacterial pathogen, Pseudomonas syringae pv. glycinea, that causes bacterial blight in soybean. We mapped PSS1 to a region very close to the southern telomere of chromosome 3 that carries no known disease resistance genes. CONCLUSIONS: The study revealed that Arabidopsis PSS1 is a novel nonhost resistance gene that confers a new form of nonhost resistance against both a hemibiotrophic oomycete pathogen, P. sojae and a necrotrophic fungal pathogen, F. virguliforme that cause diseases in soybean. However, this gene does not play any role in the immunity of Arabidopsis to the bacterial pathogen, P. syringae pv. glycinea, which causes bacterial blight in soybean. Identification and further characterization of the PSS1 gene would provide further insights into a new form of nonhost resistance in Arabidopsis, which could be utilized in improving resistance of soybean to two serious pathogens.     

The impact of culturally competent diabetes care interventions for improving diabetes-related outcomes in ethnic minority groups: a systematic review

Diabet. Med. 29, 1237-1252 (2012) ABSTRACT: Aim To examine the evidence on culturally competent interventions tailored to the needs of people with diabetes from ethnic minority groups. Methods MEDLINE (NHS Evidence), CINAHL and reference lists of retrieved papers were searched from inception to September 2011; two National Health Service specialist libraries were also searched. Google, Cochrane and DARE databases were interrogated and experts consulted. Studies were included if they reported primary research on the impact of culturally competent interventions on outcome measures of any ethnic minority group with diabetes. Paper selection and appraisal were conducted independently by two reviewers. The heterogeneity of the studies required narrative analysis. A novel culturally competent assessment tool was used to systematically assess the cultural competency of each intervention. Results Three hundred and twenty papers were retrieved and 11 included. Study designs varied with a diverse range of service providers. Of the interventions, 64% were found to be highly culturally competent (scoring 90-100%) and 36% moderately culturally competent (70-89%). Data were collected from 2616 participants on 22 patient-reported outcome measures. A consistent finding from 10 of the studies was that any structured intervention, tailored to ethnic minority groups by integrating elements of culture, language, religion and health literacy skills, produced a positive impact on a range of patient-important outcomes. Conclusions Benefits in using culturally competent interventions with ethnic minority groups with diabetes were identified. The majority of interventions described as culturally competent were confirmed as so, when assessed using the culturally competent assessment tool. Further good quality research is required to determine effectiveness and cost-effectiveness of culturally competent interventions to influence diabetes service commissioners.     

Serological survey of antibodies to Toxoplasma gondii in sheep, cattle, and buffaloes in Punjab, India

Sera from 186 sheep, 83 cattle, and 103 water buffaloes from Punjab, India, were evaluated for antibodies to Toxoplasma gondii using a commercial ELISA kit. This study was planned using a 2-stage random sampling procedure and sampling software 'survey toolbox.' In the first step, villages were selected randomly from a sampling frame of all the villages of Punjab, followed by selection of owners and animals in the second step. Antibodies to T. gondii were found in 7 of 186 sheep, 2 of 83 cattle, and 3 of 103 buffaloes. Results indicate a low prevalence of T. gondii in ruminants tested.     

Monitoring of the adenovirus production process by flow cytometry

Adenovirus (Ad) has become the vector of choice for gene therapy clinical protocols worldwide; it is the only viral vector to date that has been licensed for use in a gene therapy treatment. There is, however, a need to develop a simple, reliable at-line method to monitor the production of virus and recombinant proteins (r-proteins) that have no intrinsic reporter properties. Here we utilize flow cytometry to measure cell size, granularity, and DNA content in a single-step analysis and to correlate these parameters to the production of a type-5 Ad (Ad5) expressing the recombinant green fluorescent protein (GFP). Clear correlations between these parameters and productivity are made, with forward scatter and DNA content showing the highest correlation coefficients, 0.9 and 0.83 for virus production and r-protein production, respectively. Measuring these parameters requires little or no processing of the cells from culture to analysis. These parameters have been used successfully to monitor, at-line, the amount of Ad and r-protein product in a 293-Ad system.     

Photochemistry of dyes and fluorochromes used in biology and medicine: some physicochemical background and current applications

An overview of the basic principles of photochemistry is presented to facilitate discussion of fluorescence, quenching and quantum yields. These topics in turn provide the foundation for an account of fluorescence spectroscopy and its application to microscopy. A brief overview of light microscopy and the application of fluorescence microscopy is given. The influences of molecular features, such as aromatic character and substitution patterns, on color and fluorescence are described. The concept of color fading is considered with particular reference to its effect on microscopic preparations. A survey of representative fluorescent probes is provided, and their sensitivity, application, and limitations are described. The phototoxicity of fluorescent molecules is discussed using biomembranes and DNA as examples of targets of toxicity. Photodynamic therapy, a relatively new clinical application of phototoxicity, is described. Both anticancer and antimicrobial applications are noted, and an assessment is given of the current ideas on the ideal physicochemical properties of the sensitizing agents for such applications.     

Species confirmation of fungal isolates by molecular analysis

Traditional taxonomy of hyphomycetes has been based on conidial morphology and development. In order to confirm species level for the detection and identification of the entomopathogenic fungus, we analysed the species-specific fingerprints to investigate molecular characteristics within isolates of six species and to resolve morphologically atypical isolates. The extent of fingerprint profile observed by RAPD was sufficient to confirm the species level of all the isolates. The genetic similarity among morphologically identified isolates of each species was considerably higher, allowing us to conclude that all the isolates are of same species. These results establish a molecular framework for further taxonomic, phylogenetic and comparative biological investigations.     

Autoradiographic and liquid scintillation assessment of beta-amino-propionitrile-induced inhibition of collagen maturation using 3H-proline and 3H-lysine

BAPN (0.1 mg/day) was injected into chick embryos for 4 days starting on the 7th day of incubation. On the 11th day, the embryos were administered either 3H-proline or 3H-lysine. 36 h later, the incorporation of each isotope by the periosteal osteogenic cells as well as into bone matrix was investigated by autoradiography. The incorporation of the two isotopes into whole bones was assessed by liquid scintillation counting. 3H-proline incorporation into the cellular or matrical compartments was unaffected by treatment. As compared to the controls, 3H-lysine label in BAPN-treated embryonic bones was significantly higher in the cellular compartment but was reduced over the bone matrix. The data provide the first direct morphological evidence that BAPN probably induces certain changes in the maturation of collagen involving lysyl residues which result in an inhibition of cross-linkage formation in collagen.