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Alternaria brassicicola – Brassicaceae pathosystem: insights into the infection process and resistance mechanisms under optimized artificial bio-assay
Get PDFHeavy losses incited yearly by Alternaria brassicicola on the vegetable Brassicaceae have prompted our search for sources of genetic resistance against the pathogen and the resultant disease, dark leaf spot. We optimized several parameters to test the performance of the plants under artificial inoculations with this pathogen, including leaf age and position, inoculum concentration, and incubation temperature. Using these optimized conditions, we screened a collection of 38 Brassicaceae cultigens with two methods (detached leaf and seedlings). Our results show that either method can be used for the A. brassicicola resistance breeding, and that the plant genotype was crucial in determining its response to the pathogen. The bio-assays for A. brassicicola resistance were run under more stringent lab conditions than the field tests (natural epidemics), resulting in identification of two interspecific hybrids that might be used in breeding programs. Based on the results of the biochemical analyses, reactive oxygen species and red-ox enzymes interplay has been suggested to determine the outcome of the plant-A. brassicicola interplay. Confocal microscopy analyses of the leaf samples provided data on the pathogen mode of infection: Direct epidermal infection or stomatal attack were related to plant resistance level against A. brassicicola among the cultigens tested. Further, the microscopic analyses suggested rapid actin network activation of the host cells around the papillas deposited under the pathogen appressorium
Application of UAV BVLOS remote sensing data for multi-faceted analysis of Antarctic ecosystem
Get PDFA photogrammetric flight was performed in December 2016 as BVLOS (Beyond Visual Line of Sight) operation over Penguin Island (South Shetland Islands, Western Antarctica). Images were taken by the PW-ZOOM fixed-wing UAV equipped with a digital SLR Canon 700D camera. The flight was performed at 550 m ASL and covered a total distance of 231.58 km. The plane takeoff and landing site was near the H. Arctowski Polish Antarctic Station (Arctowski) on King George Island, South Shetlands. The main aim of the mission was to collect environmental data to estimate the size of penguin and pinniped breeding populations and to map vegetation cover and landforms. The plane returned to Arctowski with 1630 images of Penguin Island with the ground sample distance (GSD) lower than 0.07 m. The analysis of developed ortophoto allowed us to locate and identify individuals of two penguin species (Adélie and chinstrap), and individuals of two species of pinnipeds (Southern elephant seal and Weddell seal). Three types of tundra communities were mapped together with numerous landforms such as: volcanic, mass movement, fluvial, coastal and aeolian ones. The UAV BVLOS photogram-metric operation proved to be very robust in gathering valuable qualitative and quantitative data necessary for monitoring distant and isolated polar environments
Cyclosporine Metabolites’ Metabolic Ratios May Be Markers of Cardiovascular Disease in Kidney Transplant Recipients Treated with Cyclosporine A-Based Immunosuppression Regimens
Get PDFCerebrovascular reactivity and cerebral perfusion of rats with acute liver failure: role of L-glutamine and asymmetric dimethylarginine in L-arginine-induced response
Get PDFCerebral blood flow (CBF) is impaired in acute liver failure (ALF), however, the complexity of the underlying mechanisms has often led to inconclusive interpretations. Regulation of CBF depends at least partially on variations in the local brain L‐arginine concentration and/or its metabolic rate. In ALF, other factors, like an increased concentration of asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor and elevated level of L‐glutamine, may contribute to CBF alteration. This study demonstrated strong differences in the reactivity of the middle cerebral arteries and their response to extravascular L‐arginine application between vessels isolated from rats with thioacetamide (TAA)‐induced ALF and control animals. Our results also showed the decrease in the cerebral perfusion in TAA rats measured by arterial spin labeling perfusion magnetic resonance. Subsequently, we aimed to investigate the importance of balance between the concentration of ADMA and L‐arginine in the CBF regulation. In vivo, intraperitoneal L‐arginine administration in TAA rats corrected: (i) decrease in cerebral perfusion, (ii) decrease in brain extracellular L‐arginine/ADMA ratio and (iii) increase in brain L‐glutamine concentration. Our study implicates that impaired vascular tone of cerebral arteries is most likely associated with exposure to high ADMA and L‐glutamine levels resulting in limited availability of L‐arginine and might be responsible for reduced cerebral perfusion observed in AL
Non-steroidal anti-inflammatory drugs are safe with respect to the transcriptome of human dermal fibroblasts
Get PDFNon-steroidal anti-inflammatory drugs (NSAIDs) provide important benefits to millions of patients, but are associated
with a number of serious adverse events. These adverse drug reactions are an important clinical issue
and a serious public health risk. While most unfortunate responses in human to NSAIDs are mild and may
disappear after decreasing the dose or withdrawal of the drug, some of them can produce serious outcomes.
Currently, little is known regarding the effects of NSAIDs on global RNA expression in normal, non-transformed
cells. Therefore, in this report, the effect of NSAIDs, COX-nonspecific and COX-2-specific inhibitors, indomethacin
and nimesulide respectively, commonly used medications worldwide for the reduction of pain,
fever, inflammation and stiffness, on transcriptomic signature of human dermal fibroblasts was investigated. A
total of 3803 differentially expressed genes with a fold change greater than or equal to 1.3 and below than or
equal to 0.7 for whole genome transcripts, with a P value of<0.05 were identified in response to all applied
conditions. We found that although the total number of deregulated genes was relatively high at such criteria,
changes in fibroblast transcriptome profile after treatment at selected experimental conditions were however
smallish, as the selected drugs slightly modulate transcriptome with only a few genes with expression altered a
bit more than twice. Nevertheless, transcriptomic data has its own limitations and it cannot reflect all posttranscriptional
changes, which in turn may cause same risks, especially for a long time of medication
A model species for agricultural pest genomics: the genome of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)
Get PDFThe Colorado potato beetle is one of the most challenging agricultural pests to manage. It has shown a spectacular ability to adapt to a variety of solanaceaeous plants and variable climates during its global invasion, and, notably, to rapidly evolve insecticide resistance. To examine evidence of rapid evolutionary change, and to understand the genetic basis of herbivory and insecticide resistance, we tested for structural and functional genomic changes relative to other arthropod species using genome sequencing, transcriptomics, and community annotation. Two factors that might facilitate rapid evolutionary change include transposable elements, which comprise at least 17% of the genome and are rapidly evolving compared to other Coleoptera, and high levels of nucleotide diversity in rapidly growing pest populations. Adaptations to plant feeding are evident in gene expansions and differential expression of digestive enzymes in gut tissues, as well as expansions of gustatory receptors for bitter tasting. Surprisingly, the suite of genes involved in insecticide resistance is similar to other beetles. Finally, duplications in the RNAi pathway might explain why Leptinotarsa decemlineata has high sensitivity to dsRNA. The L. decemlineata genome provides opportunities to investigate a broad range of phenotypes and to develop sustainable methods to control this widely successful pest
How much of the invader’s genetic variability can slip between our fingers? A case study of secondary dispersal of Poa annua on King George Island (Antarctica)
Get PDFWe studied an invasion of Poa annua on King George Island (Maritime Antarctic). The
remoteness of this location, its geographic isolation, and its limited human traffic provided
an opportunity to trace the history of an invasion of the species. Poa annua was
recorded for the first time at H. Arctowski Polish Antarctic Station in the austral summer
of 1985/6. In 2008/9, the species was observed in a new locality at the Ecology
Glacier Forefield (1.5 km from “Arctowski”). We used AFLP to analyze the genetic
differences among three populations of P. annua: the two mentioned above (Station
and Forefield) and the putative origin of the introduction, Warsaw (Poland). There was
38% genetic variance among the populations. Pairwise ФPT was 0.498 between the
Forefield and Warsaw populations and 0.283 between Warsaw and Station. There were
15 unique bands in the Warsaw population (frequency from 6% to 100%) and one in
the Station/Forefield populations (which appears in all analyzed individuals from both
populations). The Δ(K) parameter indicated two groups of samples: Warsaw/Station
and Forefield. As indicated by Fu’s Fs statistics and an analysis of mismatch distribution,
the Forefield population underwent a bottleneck and/or founder effect. The
Forefield population was likely introduced by secondary dispersal from the Station
population
Crystal structure of the modification-dependent SRA-HNH endonuclease TagI.
Get PDFTagI belongs to the recently characterized SRA-HNH family of modification-dependent restriction endonucleases (REases) that also includes ScoA3IV (Sco5333) and TbiR51I (Tbis1). Here, we present a crystal structure of dimeric TagI, which exhibits a DNA binding site formed jointly by the nuclease domains, and separate binding sites for modified DNA bases in the two protomers. The nuclease domains have characteristic features of HNH/ββα-Me REases, and catalyze nicks or double strand breaks, with preference for /RY and RYN/RY sites, respectively. The SRA domains have the canonical fold. Their pockets for the flipped bases are spacious enough to accommodate 5-methylcytosine (5mC) or 5-hydroxymethylcytosine (5hmC), but not glucosyl-5-hydroxymethylcytosine (g5hmC). Such preference is in agreement with the biochemical determination of the TagI modification dependence and the results of phage restriction assays. The ability of TagI to digest plasmids methylated by Dcm (C5mCWGG), M.Fnu4HI (G5mCNGC) or M.HpyCH4IV (A5mCGT) suggests that the SRA domains of the enzyme are tolerant to different sequence contexts of the modified base
