Effect of climate change on sporulation of the teleomorphs of Leptosphaeria species causing stem canker of brassicas

Leptosphaeria maculans and L. biglobosa are closely related sibling fungal pathogens that cause phoma leaf spotting, stem canker (blackleg) and stem necrosis of oilseed rape (Brassica napus). The disease is distributed worldwide, and it is one of the main causes of considerable decrease in seed yield and quality. Information about the time of ascospore release at a particular location provides important data for decision making in plant protection, thereby enabling fungicides to be used only when necessary and at optimal times and doses. Although the pathogens have been studied very extensively, the effect of climate change on the frequencies and distributions of their aerially dispersed primary inoculum has not been reported to date. We have collected a large dataset of spore counts from Poznan, located in central-west part of Poland, and studied the relationships between climate and the daily concentrations of airborne propagules over a period of 17 years (1998–2014). The average air temperature and precipitation for the time of development of pseudothecia and ascospore release (July–November), increased during the years under study at the rates of 0.1 °C and 6.3 mm per year. The day of the year (DOY) for the first detection of spores, as well as the date with maximum of spores, shifted from 270 to 248 DOY, and from 315 to 265 DOY, respectively. The acceleration of the former parameter by 22 days and the latter by 50 days has great influence on the severity of stem canker of oilseed rape

Molecular screening for avirulence alleles AvrLm1 and AvrLm6 in airborne inoculum of Leptosphaeria maculans and winter oilseed rape (Brassica napus) plants from Poland and the UK

A combination of staining, light microscopy and SYBR green- and dual-labelled fluorescent probe-based qPCR chemistries with species- and gene-specific primers was employed to evaluate fluctuations in the aerial biomass of Leptosphaeria maculans spores captured by volumetric spore trappings in Poznan, Poland (2006, 2008) and Harpenden, UK (2002, 2006). Arising from these surveys, DNA samples extracted from Burkard spore-trap tapes were screened for fluctuation patterns in the frequencies of AvrLm1 and AvrLm6, the most prominent of the 15 genes that code for avirulence effectors in this Dothideomycete cause of the destructive phoma stem canker disease of oilseed rape worldwide. In Poznan, very low frequencies of AvrLm1 allele were found in the autumn of both 2006 and 2008, reflecting significantly increased cultivation of rape seed with Rlm1-based resistance. In contrast, at least six folds-higher frequencies of AvrLm6, which were also confirmed by end-point PCR bioassays on phoma-infected leaves from the same region of Poland, were obtained during both years. In the UK, however, relatively higher AvrLm1 allele titres were found in L. maculans spores captured in air samples from the autumn of 2002 on the experimental fields of Rothamsted Research, Harpenden, that were historically sown to genetically heterogeneous B. napus cultivars. In the 2006 screen these levels had plummeted, to a 1:4 ratio, in favour of frequencies of the AvrLm6 allele. Patterns of fluctuations in erg11 (CYP51) fragments coding for sterol 14α-demethylase suggest October as the month with the most viable wind-dispersed L. maculans propagules of each season of the screens

Effect of ambient humidity on dichotomous sampler coarse/fine ratios

Atmospheric aerosols were measured in August 1983 on Allegheny Mountain and Laurel Hill in southwestern Pennsylvania. Ambient humidity was observed to influence the coarse to fine particle ratios as determined by dichotomous samplers. This influence is evident in the particle mass and in its component chemical species. The sampling run with the most pronounced mass shift resulted in an apparent loss of 50 % of the fine mass and 66 % of the fine particle sulfur to the coarse fraction. The magnitude of the mass shift appears to be related to the length of time that the aerosol was in a saturated environment and also to the original dry particle size. These observations have serious implications for receptor modeling with dichotomous sampler data whenever only the fine particles are considered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27611/1/0000655.pd

The sources of aerosol elemental carbon at Allegheny Mountain

Aerosol elemental carbon measurements were taken at two rural sites in southwestern Pennsylvania during August 1983. Carbon, though a small part of the aerosol mass at both sites, was a leading constituent of the aerosol on an atom basis. Time-weighted average concentrations at Allegheny Mountain and Laurel Hill were 1.2 and 1.4 [mu]g m-3, respectively. Absolute Principal Component Analysis followed by multiple regression and Chemical Mass Balance techniques were utilized to apportion the measured elemental carbon to its sources. Motor vehicles were estimated to be the largest source of elemental carbon at the two sites, contributing 41-68% and 34-56% at Allegheny Mountain and Laurel Hill, respectively.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28963/1/0000800.pd

Autoantibodies against the chemokine receptor 3 predict cardiovascular risk

BACKGROUND AND AIMS: Chronic inflammation and autoimmunity contribute to cardiovascular (CV) disease. Recently, autoantibodies (aAbs) against the CXC-motif-chemokine receptor 3 (CXCR3), a G protein-coupled receptor with a key role in atherosclerosis, have been identified. The role of anti-CXCR3 aAbs for CV risk and disease is unclear. METHODS: Anti-CXCR3 aAbs were quantified by a commercially available enzyme-linked immunosorbent assay in 5000 participants (availability: 97.1%) of the population-based Gutenberg Health Study with extensive clinical phenotyping. Regression analyses were carried out to identify determinants of anti-CXCR3 aAbs and relevance for clinical outcome (i.e. all-cause mortality, cardiac death, heart failure, and major adverse cardiac events comprising incident coronary artery disease, myocardial infarction, and cardiac death). Last, immunization with CXCR3 and passive transfer of aAbs were performed in ApoE(-/-) mice for preclinical validation. RESULTS: The analysis sample included 4195 individuals (48% female, mean age 55.5 ± 11 years) after exclusion of individuals with autoimmune disease, immunomodulatory medication, acute infection, and history of cancer. Independent of age, sex, renal function, and traditional CV risk factors, increasing concentrations of anti-CXCR3 aAbs translated into higher intima-media thickness, left ventricular mass, and N-terminal pro-B-type natriuretic peptide. Adjusted for age and sex, anti-CXCR3 aAbs above the 75th percentile predicted all-cause death [hazard ratio (HR) (95% confidence interval) 1.25 (1.02, 1.52), P = .029], driven by excess cardiac mortality [HR 2.51 (1.21, 5.22), P = .014]. A trend towards a higher risk for major adverse cardiac events [HR 1.42 (1.0, 2.0), P = .05] along with increased risk of incident heart failure [HR per standard deviation increase of anti-CXCR3 aAbs: 1.26 (1.02, 1.56), P = .03] may contribute to this observation. Targeted proteomics revealed a molecular signature of anti-CXCR3 aAbs reflecting immune cell activation and cytokine-cytokine receptor interactions associated with an ongoing T helper cell 1 response. Finally, ApoE(-/-) mice immunized against CXCR3 displayed increased anti-CXCR3 aAbs and exhibited a higher burden of atherosclerosis compared to non-immunized controls, correlating with concentrations of anti-CXCR3 aAbs in the passive transfer model. CONCLUSIONS: In individuals free of autoimmune disease, anti-CXCR3 aAbs were abundant, related to CV end-organ damage, and predicted all-cause death as well as cardiac morbidity and mortality in conjunction with the acceleration of experimental atherosclerosis

The influence of the fungicide containing flusilazole on the effectiveness of the protection of oilseed rape against stem canker of brassicas

Sucha zgnilizna kapustnych jest groźną chorobą rzepaku ozimego i jarego, wywoływaną przez grzyby workowe Leptosphaeria maculans i L. biglobosa. Pierwotnym źródłem porażenia roślin rzepaku są zarodniki workowe, które powstają w owocnikach stadium doskonałego, tworzonych na resztkach pożniwnych rzepaku z poprzedniego sezonu wegetacyjnego. Celem niniejszej pracy było porównanie skuteczności ochrony rzepaku ozimego przed suchą zgnilizną kapustnych w zależności od terminu stosowania fungicydu zawierającego flusilazol i weryfikacja wskazań monitorowania prowadzonego w ramach Systemu Prognozowania Epidemii Chorób. Badania w warunkach polowych wykonywano w ZDOO Krościna Mała w sezonach 2009/2010 oraz 2010/2011 na roślinach odmiany PR46W10. Oznaczanie zmian w dobowym stężeniu askospor patogenicznych grzybów Leptosphaeria spp. w powietrzu prowadzono metodą objętościową z wykorzystaniem chwytacza zarodników i ziaren pyłku firmy Burkard Manufacturing. Obserwacje zdrowotności roślin rzepaku przeprowadzono jesienią i przed żniwami. Oznaczono także plon rzepaku przy 9% wilgotności nasion. Gatunek grzybów rodzaju Leptosphaeria izolowane z liści i łodyg rzepaku oznaczano na podstawie cech morfologicznych kultur na pożywce agarowej.Skuteczność ochrony roślin rzepaku przed suchą zgnilizną kapustnych w sezonie jesiennym w znacznym stopniu zależała od liczby dni z zarodnikami workowymi grzybów L. maculansi L. biglobosa w powietrzu oraz od warunków pogodowych. Wykazano, że optymalnym terminem zabiegu fungicydowego przeciwko suchej zgniliźnie kapustnych jest opryskiwanie roślin w terminie następującym po najwyższym stężeniu askospor w powietrzu. W wyniku takiego zabiegu obserwowano najniższe porażenie roślin, zarówno przed ich zimowym spoczynkiem jak też przed zbiorem rzepaku, a także znaczący wzrost plonu nasion. Proporcje pomiędzy gatunkami L. maculans i L. biglobosa zależały od rodzaju i ilości inokulum, sezonu i były odmienne naróżnych organach roślin rzepaku. W okresie jesiennym na liściach przeważał gatunek L. maculans, natomiast na łodygach dominował gatunek L. biglobosa.Stem canker of brassicas is a damaging disease of winter and spring oilseeed rape, caused by ascomycetous fungi Leptosphaeria maculans and L. biglobosa. The initial source of plant infection are ascospores, that are formed in fruiting bodies of the perfect stage (pseudothecia), on stubble of oilseed rape from the previous vegetative season. In spite of broad spectrum of experiments on stem canker in Poland, the research on the time of fungicide treatments and its dependence on the presence and concentration of ascospores in the air, has not been undertaken by now. In this paper the effectiveness of fungicide treatments at different times of application in autumn and early spring has been compared in relation to monitoring done in the System of Forecasting of Disease Epidemics. The field experiments were carried out in the Experimental Station of Cultivar Testing in Krościna Mała, located in Lower Silesia in the seasons 2009/2010 and 2010/2011, with the use of winter oilseed rape cultivar PR46W10, on individual plots of 15 m 2, designed in completely randomized blocks. The evaluation of changes in diurnal ascospore concentration was done with the volumetric method, using a spore sampler produced by Burkard Manufacturing. The calculation of the number of ascospores of Leptosphaeria spp. was done with light microscope under 200x magnification. Protective treatments were done using a fungicide containing flusilazole, with weekly intervals starting from the end of September till mid-November and in early spring, just after the start of plant vegetation, following winter pause.The assessment of plant healthiness was done in autumn and before harvest. Disease incidence and severity was evaluated for each experimental variant; there were 150 plants evaluated for each individual plot. Then, the pathogens were isolated from infected leaves and stems. The fungi belonging to the genus Leptosphaeria were identified at the species level, based on culture morphology on potato-glucose agar medium. Plant yield was evaluated at 9% seed humidity. Statistical analyses (variance analysis, Tukey’s test and Pearson’s correlation coefficient) were done using GenStat software version 12.1.The efficiency of plant protection of oilseed rape against stem canker in autumn greatly depended on the number of days with ascospores of Leptosphaeria maculans and L. biglobosa in air samples and on climatic conditions. High percentage of days with ascospores present in the air and warm but rainy weather enhanced plant infection, so that one fungicide treatment could not fully stop the infection of all plants. It was found that one fungicide spray resulted in the highest reduction of infected plants when it was done on the day of the highest ascospore release till no longer than three weeks afterwards. The highest increase of seed yield was obtained at 4 (2011) and 9 (2010) days after the peak ascospore release. The proportion between L. maculans and L. biglobosa depended on the season and it was different on leaves and stems of oilseed rape. In autumn L. maculans prevailed on leaves and before harvest L. biglobosa was the dominating species on stems