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.     

Decomposition of Cr(V)-diols to Cr(III) Complexes by <Emphasis Type="Italic">Arthrobacter oxydans</Emphasis>

We demonstrated previously that Cr(VI) is readily reduced to oxoCr(V)-diols at the surface of Arthrobacter oxydans—a Gram-positive aerobic bacteria isolated from Columbia basalt rocks originated from a highly contaminated site in the USA. Here, we report an electron spin resonance (ESR) study of Cr(III) hydroxide formation from Cr(V)-diols by this bacterial strain as cells were exposed to 35, 200, and 400 mg/L of Cr(VI) under aerobic conditions as a batch culture and as lyophilized cells. The time-dependent ESR measurements show that the half-time of Cr(III) formation is almost equal to that of Cr(V) decomposition, which is in the range of 3–6 days for all cases. This rate is at least 300 times slower than that of Cr(V) formation. Additionally, atomic absorption spectrometry was also employed to examine the time course of total chromium in bacterial cells. This is the first time the kinetics of Cr(III) complexes formation in bacteria is evaluated.     

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.     

Chromium(V) complexes generated in Arthrobacter oxydans by simulation analysis of EPR spectra

Chromium(V) is an intermediate formed during the reduction of Cr(VI) to Cr(III) compounds by various bacteria. However, little is known about the nature, localization and reactivity of Cr(V) species in microbial systems. Electron paramagnetic resonance (EPR) spectroscopy was used to study the nature of Cr(V) complexes generated in basalt-inhabiting Gram-positive Arthrobacter oxydans bacteria after exposure to high concentrations of Cr(VI). Numerical simulations of the EPR spectroscopic data provide strong evidence for at least two different diolato-type oxoCr(V) complexes (I, g(iso)=1.9801; II, g(iso)=1.9796) involving bacterial cell wall macromolecules in the Cr(VI)-A. oxydans system. The relative concentrations of the two oxoCr(V)-diolato species differ when Cr(VI) is incubated with either untreated A. oxydans cells (I:II approximately 50:50) or lyophilized cells (I:II approximately 10:90). Based upon the magnitudes of the proton superhyperfine coupling constants ((1)H a(iso)) for species I and II, the EPR simulation model is unable to distinguish unambiguously whether the oxoCr(V)-diolato species are linear alkoxides or cyclic diols (carbohydrates). The oxygen-containing functional groups associated with teichoic acids are the most likely candidates for complexation with the Cr(V) ion.     

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.