Plant virus infection development as affected by heavy metal stress

The work was focused on the investigation of possible dependencies between the development of viral infection in plants and the presence of high heavy metal concentrations in soil. Field experiments have been conducted in order to study the development of systemic tobacco mosaic virus (TMV) infection in Lycopersicon esculentum L. cv. Miliana plants under effect of separate salts of heavy metals Cu, Zn and Pb deposited in soil. As it is shown, simultaneous effect of viral infection and heavy metals in tenfold maximum permissible concentration leads to decrease of total chlorophyll content in experiment plants mainly due to the degradation of chlorophyll a. The reduction of chlorophyll concentration under the combined influence of both stress factors was more serious comparing to the separate effect of every single factor. Plants' treatment with toxic concentrations of lead and zinc leaded to slight delay in the development of systemic TMV infection together with more than twofold increase of virus content in plants that may be an evidence of synergism between these heavy metal's and virus' effects. Contrary, copper although decreased total chlorophyll content but showed protective properties and significantly reduced amount of virus in plants.     

Heavy metal soil contamination delays the appearance of virus-induced symptoms on potato but favours virus accumulation

Abstract

Here we report on the investigation of virus infection development in plants undergoing simultaneous heavy metal stress. We carried out small-scale field experiments using model system Potato virus X (PVX) – Solanum tuberosum cv. Povin' (potato) plants. Heavy metals zinc (Zn), copper (Cu) and lead (Pb) were added to the soil separately (monometal contamination) at a range of concentrations. Our results show that heavy metal stress significantly delays the appearance and potentiates severity of virus-specific symptoms on infected potato plants. We also demonstrate that PVX content in plants may increase tremendously in response to this abiotic stressor. Finally, we provide links to the possible consequences in the context of virus epidemiology.     

Patterns of molecular and phenotypic diversity in pearl millet [<Emphasis Type="Italic">Pennisetum glaucum</Emphasis>(L.) R. Br.] from West and Central Africa and their relation to geographical and environmental parameters

Background  

The distribution area of pearl millet in West and Central Africa (WCA) harbours a wide range of climatic and environmental conditions as well as diverse farmer preferences and pearl millet utilization habits which have the potential to lead to local adaptation and thereby to population structure. The objectives of our research were to (i) assess the geographical distribution of genetic diversity in pearl millet inbreds derived from landraces, (ii) assess the population structure of pearl millet from WCA, and (iii) identify those geographical parameters and environmental factors from the location at which landraces were sampled, as well as those phenotypic traits that may have affected or led to this population structure. Our study was based on a set of 145 inbred lines derived from 122 different pearl millet landraces from WCA.     

Investigation of Ukrainian isolates of cucumber green mottle mosaic virus

Abstract

Isolates of cucumber green mottle mosaic virus (CGMMV) obtained from three greenhouses in Ukraine have been identified. The rabbit antisera have been generated for these isolates. These antisera can be used for diagnostics of CGMMV in plant material by indirect ELISA. Analysis of cDNA sequences of capsid protein of these viruses confirmed that they may be grouped into novel strain of CGMMV.     

Genotypes and haplotypes in the insulin-like growth factors, their receptors and binding proteins in relation to plasma metabolic levels and mammographic density

Background

Chronic inflammatory diseases including inflammatory bowel disease (IBD; Crohn's disease and ulcerative colitis), psoriasis and rheumatoid arthritis (RA) afflict millions of people worldwide, but their pathogenesis is still not well understood. It is also not well known if distinct changes in gene expression characterize these diseases and if these patterns can discriminate between diseased and control patients and/or stratify the disease. The main focus of our work was the identification of novel markers that overlap among the 3 diseases or discriminate them from each other.

Methods

Diseased (n = 13, n = 15 and n = 12 in IBD, psoriasis and RA respectively) and healthy patients (n = 18) were recruited based on strict inclusion and exclusion criteria; peripheral blood samples were collected by clinicians (30 ml) in Venous Blood Vacuum Collection Tubes containing EDTA and peripheral blood mononuclear cells were separated by Ficoll gradient centrifugation. RNA was extracted using Trizol reagent. Gene expression data was obtained using TaqMan Low Density Array (TLDA) containing 96 genes that were selected by an algorithm and the statistical analyses were performed in Prism by using non-parametric Mann-Whitney U test (P-values < 0.05).

Results

Here we show that using a panel of 96 disease associated genes and measuring mRNA expression levels in peripheral blood derived mononuclear cells; we could identify disease-specific gene panels that separate each disease from healthy controls. In addition, a panel of five genes such as ADM, AQP9, CXCL2, IL10 and NAMPT discriminates between all samples from patients with chronic inflammation and healthy controls. We also found genes that stratify the diseases and separate different subtypes or different states of prognosis in each condition.

Conclusions

These findings and the identification of five universal markers of chronic inflammation suggest that these diseases have a common background in pathomechanism, but still can be separated by peripheral blood gene expression. Importantly, the identified genes can be associated with overlapping biological processes including changed inflammatory response. Gene panels based on such markers can play a major role in the development of personalized medicine, in monitoring disease progression and can lead to the identification of new potential drug targets in chronic inflammation.     

Evidence for plant viruses in the region of Argentina Islands, Antarctica

This work focused on the assessment of plant virus occurrence among primitive and higher plants in the Antarctic region. Sampling occurred during two seasons (2004/5 and 2005/6) at the Ukrainian Antarctic Station 'Academician Vernadskiy' positioned on Argentina Islands. Collected plant samples of four moss genera (Polytrichum, Plagiatecium, Sanionia and Barbilophozia) and one higher monocot plant species, Deschampsia antarctica, were further subjected to enzyme-linked immunosorbent assay to test for the presence of common plant viruses. Surprisingly, samples of Barbilophozia and Polytrichum mosses were found to contain antigens of viruses from the genus Tobamovirus, Tobacco mosaic virus and Cucumber green mottle mosaic virus, which normally parasitize angiosperms. By contrast, samples of the monocot Deschampsia antarctica were positive for viruses typically infecting dicots: Cucumber green mottle mosaic virus, Cucumber mosaic virus and Tomato spotted wilt virus. Serological data for Deschampsia antarctica were supported in part by transmission electron microscopy observations and bioassay results. The results demonstrate comparatively high diversity of plant viruses detected in Antarctica; the results also raise questions of virus specificity and host susceptibility, as the detected viruses normally infect dicotyledonous plants. However, the means of plant virus emergence in the region remain elusive and are discussed.