A new approach for cytokinin isolation from Arabidopsis tissues using miniaturized purification: pipette tip solid-phase extraction     

Svacinova J  Novak O  Plackova L  Lenobel R  Holik J  Strnad M  Dolezal K 《Plant methods》2012,8(1):17

ABSTRACT: BACKGROUND: We have developed a new analytical approach for isolation and quantification of cytokinins (CK) in minute amounts of fresh plant material, which combines a simple one-step purification with ultra-high pressure liquid chromatography-fast scanning tandem mass spectrometry. RESULTS: Plant tissue samples (1-5 mg FW) were purified by stop-and-go-microextraction (StageTip purification), which previously has only been applied for clean-up and pre-concentration of peptides. We found that a combination of two reverse phases and one cation-exchange phase, was the best tool, giving a total extraction recovery higher than 80%. The process was completed by a single chromatographic analysis of a wide range of naturally occurring cytokinins (bases, ribosides, O- and N-glucosides, and nucleotides) in 24.5 minutes using an analytical column packed with sub-2-microne particles. In multiple reaction monitoring mode, the detection limits ranged from 0.05 to 5 fmol and the linear ranges for most cytokinins were at least five orders of magnitude. The StageTip purification was validated and optimized using samples of Arabidopsis thaliana seedlings, roots and shoots where eighteen cytokinins were successfully determined. CONCLUSIONS: The combination of microextraction with one-step high-throughput purification provides fast, effective and cheap sample preparation prior to qualitative and quantitative measurements. Our procedure can be used after modification also for other phytohormones, depending on selectivity, affinity and capacity of the selected sorbents.  相似文献   

A new approach for cytokinin isolation from Arabidopsis tissues using miniaturized purification: pipette tip solid-phase extraction     

Jana Svačinová  Ondřej Novák  Lenka Plačková  René Lenobel  Josef Holík  Miroslav Strnad  Karel Doležal 《Plant methods》2012,8(1):1-14

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The Effect of Growth Regulators and a Biostimulator on the Health Status,Yield and Yield Components of Potatoes (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.)     

Małgorzata Głosek-Sobieraj  Bożena Cwalina-Ambroziak  Karel Hamouz 《Gesunde Pflanzen》2018,70(1):1-11

In this study, the influence of potato cultivars Irga, Satina, Valfi, Blaue St. Galler and Highland Burgundy Red (HB Red), growth regulators: Bio-Algeen S?90, Kelpak SL and Trifender WP, and the biostimulator Asahi SL on the health status of potato plants and tuber yield was investigated. The severity of late blight and early blight was estimated during the growing season. After harvest, potato tuber yield was determined according to size fractions. The applied treatments significantly reduced the severity of late blight in cv. Irga (Kelpak SL), Valfi (Bio-Algeen S-90, Kelpak SL, Trifender WP) and Blaue St. Galler (Trifender WP) in 2013. In 2015, the symptoms of early blight were significantly reduced in cv. Irga after the application of all tested bioregulators. HB Red was characterized by the best health status among the evaluated cultivars. Kelpak SL and Bio-Algeen S-90 increased the tuber yield of cvs. Irga and HB Red, respectively, in 2013, and Trifender WP increased the tuber yield of cv. Satina in 2014. In the first year of the study, the applied growth regulators and biostimulator significantly increased the percentage of medium-sized tubers of cv. Blaue St. Galler, and Bio-Algeen S-90 increased the percentage of medium-sized tubers of cv. HB Red.  相似文献   

Enterotoxigenic Escherichia coli (ETEC) and Klebsiella pneumoniae isolated from dogs with diarrhoea     

Pekka Olson  ke Hedhammar  Ahmed Faris  Karel Krovacek  Torkel Wadstrm 《Veterinary microbiology》1985,10(6):577-589

Faecal samples from 148 dogs with diarrhoea and from 15 healthy dogs were cultured for bacterial pathogens with enterotoxigenic properties. The aim of the study was to define the toxin profile (production of heat-labile [LT] and heat-stable [ST] toxins) and possible surface fimbrial antigens. Enterotoxigenic bacteria were isolated from 6 (4.1%) dogs with diarrhoea, four of these were Escherichia coli and two were Klebsiella pneumoniae. The E. coli strains and K. pneumoniae strains were producing both LT and ST toxins. The LT toxin from these strains was not neutralized by human anti-LT serum or anti-choleragen and did not cause coagglutination with Staphylococcus aureus coated with anti-human-LT. This suggests that the LT toxin produced by these canine isolates is non-identical to LT toxin from human strains.

Three of the ETEC strains were haemagglutinating and showed surface hydrophobic properties. Electron microscopy showed that canine ETEC isolates possessed fimbriae of two different types: thick (5–5.5 nm) and thin (2–3 nm).  相似文献   

Isolation, biochemical and serological characterisation of Plesiomonas shigelloides from freshwater in Northern Europe     

Krovacek K  Eriksson LM  González-Rey C  Rosinsky J  Ciznar I 《Comparative immunology, microbiology and infectious diseases》2000,23(1):45-51

Isolation and characterisation of Plesiomonas shigelloides from fresh water in Northern Europe is reported in this study. The organisms were isolated from two lakes and a river in Sweden. All isolates of P. shigelloides showed an identical biochemical profile and belonged to different serotypes, namely, O18, O23, O26, O58 and O60. The study indicates that P. shigelloides may occur in the aquatic environment of cold climates and as a result, it is likely to be associated with human infections caused by waterborne pathogens in geographical areas with similar climatic conditions.  相似文献   

Philanthotoxins: A review of the diversity of actions on synaptic transmission     

Tom Piek  Stuart J. Dunbar  Karel S. Kits  Jan van Marle  Henk van Wilgenburg 《Pest management science》1985,16(5):488-494

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Effects of nitrate nitrogen pollution on Central European unionid bivalves revealed by distributional data and acute toxicity testing     

Karel Douda 《水产资源保护:海洋与淡水生态系统》2010,20(2):189-197

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Early responses of in vitro cultured fish‐growing glochidia: The effects of taurine,lipids and sera on Margaritifera margaritifera     

Felipe Escobar‐Caldern  Barbora Vodkov  Karel Douda 《Aquaculture Research》2020,51(3):1069-1076

In vitro culture has great potential for the propagation of freshwater mussels in both commercial and conservation aquaculture. The use of in vitro techniques precludes the need for host fish, thus decreasing costs and increasing efficiency. However, protocols are still lacking for many species that grow substantially during the parasitic stage. In this study, we tested the effects of taurine addition, serum type and source of lipids on the survival rate and increase in length of Margaritifera margaritifera larvae during the initial stage of culture (first 11 days of exposure to media). Our results show that taurine has no significant effect on the early survival rate of glochidia; however, the possible importance of this amino acid in subsequent stages is discussed. The use of an emulsified lipid mixture instead of traditional fish oil showed significantly higher rates of survival. Finally, the addition of serum showed variable effects, with both horse serum and newborn calf serum having higher survival in trials using mussel populations from different sources. These findings can contribute to the invention or improvement of in vitro protocols for species growing during infection and at the same time show the potential that early survival assessments could have for the development of in vitro methods in species with long parasitic stages.  相似文献   

Functional polymorphisms in Toll-like receptor genes for innate immunity in farm animals     

Karel Novák 《Veterinary immunology and immunopathology》2014,157(1-2):1-11

The exploitation of the genetic factors affecting the health status of farm animals represents an alternative approach to controlling the diseases caused by microbial pathogens. The determination of innate immunity based on the genotype of the germplasm cells is a constraint for specificity but becomes an advantage in breeding schemes. The structural deviations among Toll-like receptors (TLRs), as the most frequently studied innate immunity components, have been documented at all levels, i.e., interspecific, inter- and intravarietal, in the main farm species. The current computational methods facilitate the prediction of the functional consequences of the observed mutations. Subsequently, these predictions can be verified through immunological responsiveness and population-wide association studies. The frequency and haplotype grouping of individual polymorphisms are used to track the origin and selection coefficient as independent indicators of functional changes. The Toll-like receptor variants associated with mastitis and mycobacterial infection have been identified in cattle, consequently, the targeting of these proteins in breeding could contribute to disease control. The range of infections affected by TLR polymorphisms suggests that the improvement of innate resistance is feasible in more species. Thus, the traditional breeds and wild populations should be regarded as the resources of genetic variability accessible for these purposes.  相似文献   

Morphometric and genetic analysis of <Emphasis Type="Italic">Carassius auratus</Emphasis> complex from an artificial wetland in Morava River floodplain,Czech Republic     

Lukáŝ Veteŝník  Ivo Papouŝek  Karel Halačka  Věra Lusková  Jan Mendel 《Fisheries Science》2007,73(4):817-822

A Carassius auratus complex from an artificial wetland in the Morava River basin is composed of triploid females. Based on body depth, sampled females could be divided into two groups: (i) high-dorsal (42.5% of standard length); and (ii) low-dorsal (36.1% of standard length). Both groups differed also in number of gill rakers (50.2 versus 45.4, respectively). In concordance with morphological differences, genetic analysis proved the existence of two haplotypes in examined individuals. The first haplotype is bound to the high-dorsal form with higher number of gill rakers. This is the most frequent haplotype in populations of the C. a gibelio form in the Czech Republic. The second haplotype is characteristic of the low-dorsal form with a lower number of gill rakers. This haplotype is close to haplotypes described in the C. a. langsdorfii form, which is known from Japan. and its occurrence within haplotypes specified in European territory is sporadic.  相似文献