Volume 72, Issue 4

Anaplasma phagocytophilum is zoonotic gram-negative intracellular bacterium, which invades neutrophiles and causes febrile diseases. This bacterium is transmitted mainly by Ixodes ricinus in Europe. Due to lack of knowledge about prevalence of A. phagocytophilum in different tick species, our study was focused on hard ticks in the South Moravia. There are three hard tick species common in this region - I. ricinus, Dermacentor reticulatus and Haemaphysalis concinna . We collected 823 I. ricinus , 500 D. reticulatus and 37 H. concinna by flagging during 2009-2011 from 43 localities. We confirmed the presence of DNA of A. phagocytophilum in 3.8% I. ricinus ( n = 31), 3.6% D. reticulatus ( n = 18) and 29.7% H. concinna (n = 11) by nested PCR. All amplicons were 100% identical with sequences of A. phagocytophilum deposited in the GenBank database (accession numbers KX180948, KY11936 and KP245905, respectively). Despite the absence of clinical cases in the Czech Republic, human granulocytic anaplasmosis should be considered in patients with non-specific clinical manifestation and history of tick bite.

Germination strategy is an essential mechanism that determines plant survival in previously established populations or newly colonised sites. Carex is a group of species that has shown difficulties to germinate experimentally and also many of them failed in order to use in restoration projects. Our aim was to determine whether Carex elata and C. elongata that dominate in vegetation of Central European swamps differ in their germination strategy. We conducted germination experiments with stratified and unstratified seeds of both species to determine: 1) if they are able to germinate fresh, 2) if they exhibit a cyclic dormancy pattern, and 3) if they will germinate from a seed bank. We demonstrate fresh seed germination and no evidence of cyclic dormancy in either species. Stratification did not enhance final germination but it did accelerate germination. Seed bank seeds of both species germinate sparsely. We demonstrate that these coexisting Carex species differ with respect to final germination. The higher germination percentages of the fresh seeds compared to buried and seed bank seeds of both species probably reflect adaptation to fluctuating water-level conditions. In summary, these findings support a strategy of fresh germination in a highly-variable environment. Our study indicates that both C. elata and C. elongata are suitable for restoration projects. Successful establishment and revegetation with C. elongata may result simply from sowing fresh seeds. In contrast, seed sowing, combined with vegetatively produced seedling transplants is essential for the successful restoration of C. elata .

Maize ( Zea mays L. cv. Thermo) root segments were treated for 24 h with 100 μg mL -1 of zearalenone and its derivatives α - and β -zearalenol. The mycotoxin treatment resulted in cell death which was evident by Evans blue staining and was accompanied by DNA release/fragmentation. Mycotoxin-induced programmed cell death (MPCD) was abolished by sub-micromolar concentrations of caspase-specific peptide inhibitors pointing to a MPCD mechanism similar to animal apoptosis. Here we demostrate that exogenous ethylene and ethylene precursor (aminocyclopropane-1-carboxylic acid; ACC) substantially blocked MPCD while the ethylene biosynthesis inhibitor aminoethoxyvinylglycine (AVG) did not markedly reduce cell death rate. In addition, Western blot analyses revealed that MPCD was induced via ethylene-regulated expression of DAD1 protein. Pre-treatment of root segments with inhibitors of phospholipase C and D signalling pathway intermediates significantly reduced the rate of MPCD. Treatment with mastoparan and lyso-phosphatidic acid (L-PA), G protein activator and analogue of the lipid second messenger phosphatidic acid (PA), respectively, stimulated cell death. Furthermore, application of lipid and protein kinase inhibitors (wortmannin, Go 6983, staurosporine) also reduced cell death, indicating that various kinases are a part of signalling cascade involved in MPCD. Taken together, the results presented in this paper provide direct evidence that MPCD exhibits formal apoptotic-like features, involves caspase-mediated pathway and is regulated via ethylene and phospholipid signal transduction pathways.

Elucidating molecular mechanisms of rice responses to high manganese (Mn) stress is crucially important to manganese-resistant gene cloning, functional analysis and other research work. In the present study, we analyzed the gene expression in leaves of Mn-sensitive rice ( Oryza sativa cv. Xinxiangyou 640) exposed to high Mn stress by high-throughput sequencing. There were about 2831 differently expressed genes [the false discovery rate (FDR) ≤ 0.001 and log 2 ratio(Mn/CK) ≥ 1] among 21258 genes, in which 1336 appeared to be up-regulated and 1495 appeared to be down-regulated in rice treated with high level of Mn compared with the normal level of Mn. Under high Mn stress, the differentially expressed genes were relating to various transcription factors (TFs), large number of transporters, numerous transferase proteins, catalytic proteins, etc, involving in the major primary and secondary metabolisms. Among the rest, the genes of WRKY family were all significantly up-regulated whereas all the Aux/IAA genes were strongly down-regulated. Potassium transporters were also significantly up-regulated whereas sodium transporters were strongly down-regulated. The expression patterns of representative related genes were further confirmed by fluorescent quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). Manganese resistance mechanism in rice is very complex and is a consequence of coordinated expression of a large number of genes. This data resource contributed substantially to biological and physiological research on rice genes, and to comparative analysis of Mn-specific responses in plants.

Metacaspases are cysteine-dependent proteases essential in plant PCD. This study focused on PCD features, the metacaspase II protein (TaeMCAII) and its gene expression and dynamic distribution during the developmental process of wheat sieve elements (SEs). Our results showed that the SEs experienced enucleation, inclusion loss, cell wall thickening and decreased cytosol density during their development. The RT-qPCR and in situ hybridization showed that the transcriptional levels of TaeMCAII in the development of SEs increased to high levels 3 days after flowering (DAF), then decreased, but then sharply increased at 7 DAF. Immunohistochemical observations revealed dynamic changes of TaeMCAII at the protein level. TaeMCAII was primarily detected at 3 DAF, 4 DAF and 7 DAF, which indicated that TaeMCAII played an important role during these stages. Immunoelectron microscopy showed that TaeMCAII was first localized in the nucleus, then in the cell cytoplasm, and finally on the cell membranes and cell walls of late-stage SEs. Our study found that TaeMCAII was key in the PCD-like process of the development of SEs.

The largest rivers in Europe are under strong human pressure, resulting in habitat changes and consequently in structural changes in the quantitative and qualitative composition of fauna assemblages. The aim of this study was to identify the taxonomic structure of leech assemblages and the main environmental factors influencing their distribution pattern on a 306 km stretch of the Oder River encompassing different habitat types. Representatives of 28 leech taxa were recorded in 527 samples of bottom macrofauna. The most abundant and most frequently recorded species was the eurytopic Erpobdella octoculata , occurring in all examined habitat types. Although a significant influence of habitat type on the species composition of leech assemblages was noted, a significant positive correlation with habitat type was found only in the case of Piscicola pojmanskae and P. geometra . Our results show that abundance of food resources was the most important factor influencing the distribution of leeches.

Beaver ponds favour lentic species over the original lotic animals. The typical lentic animals are zooplankton, which can be good predictors of hydrological changes in streams caused by beaver activity. We analysed the effects of beaver dams on the zooplankton communities in small lowland streams in stream-beaver pond-stream systems. All spatial changes in the composition of zooplankton reflected the effects of physical changes introduced by the beaver dams. The rapid increase in the density of the aforementioned taxa was possible because the features typical of stagnant water reservoirs are present in beaver ponds. The number of taxa and the abundance and biodiversity of zooplankton, especially planktonic rotifers, were higher in the dam and downstream sites than in the upstream sites. Therefore, the impact of beaver ponds on the composition of zooplankton in streams below the dams is considerable, and there is an increase in the organic matter downstream, which leads to trophic changes in the stream.

Attempting to help reduce the costs of bioassessment of aquatic habitats, the aim of this study was to estimate how particular substrate types influence the ecological quality evaluation based on a multihabitat scheme proposed by the AQEM/STAR consortium. Samples of macroinvertebrates were taken from the Stupavský potok brook, a small, 4 th order calcareous stream in the Small Carpathians in Slovakia (Central Europe). Eight most suitable metrics for small Slovakian streams forming the Slovak multimetric index on seven substrate types were tested and compared with the multihabitat sample. The Saprobic Index (SI) and Index of Biocenotic Region (IBR) showed considerably worse (higher) values in the psammal and the best (lowest) values on coarse mineral substrates (lithal, akal). Similarly, values of the metrics Oligo (%), BMWP Score, Rheoindex, Rhithron Typie Index (%) and EPT reached their worst (lowest) values on psammal and the best (highest) values on coarse mineral substrates. Psammal sample showed the worst ecological quality expressed by the lowest EQR (Ecological Quality Ratio) value, most significantly differing from the multihabitat sample (Multiple Comparisons of Means: Dunnett Contrasts: –8.25, P < 0.01). We conclude that substrate types considerably influence selected metrics. Because of a relatively substantial proportion of psammal in some small Slovakian streams and its marginal influence on the overall ecological quality of the site, we suggest conduct further research addressing the effectiveness of its usage in the water management.

The main aim of this study was to describe and compare communities of oribatid mites of selected areas in montane spruce forests near Březník in the Šumava National Park, where different management strategies were used after the spruce dieback caused by massive bark beetle gradation more than 15 years ago. Naturally regenerating and salvage-logged areas were compared. Significant differences were found in the oribatid mite community composition between differently managed areas. The oribatid mite community in naturally regenerating areas was in better shape and its abundance and species composition was similar to the community of a control area in a mature and healthy spruce forest.

Detrito-bryophagy represents a specific feeding strategy in orthopterans. We evaluated the consumption rate and digestibility of two main food components (detritus and moss) in a typical detrito-bryophagous groundhopper, Tetrix subulata (L., 1758), under laboratory conditions. By analysing gravimetric consumption, we confirmed that detritus is consumed more intensively and with higher efficiency (digestibility 91%) than moss tissues represented by the offered tissues of Calliergonella cuspidata (Hedw.) Loeske (digestibility approximately 60%). Detritus seems to contain easily digestible compounds (a dominant source of nutrition); moss is also consumed obviously because of important additional functions in the diet.

Alpha-ketoglutarate (AKG), a key intermediate in the Krebs cycle and metabolism of amino acids, is one of dietary supplements studied actively during last decade. In this work, we examined the ability of dietary AKG to prevent age-related functional decline in D. melanogaster . For that, some metabolic processes and physiological functions, such as climbing activity and cold resistance, were studied in young (2 days post-eclosion) and middle-aged (24 days) D. melanogaster w 1118 adults maintained on AKG-supplemented diet. Both locomotor activity and cold resistance measured as chill coma recovery time (CCRT) impaired in middle-aged flies compared with young ones. Diet with 10 mM AKG improved climbing activity in middle-aged flies of both sexes. A positive impact of AKG on CCRT was found in young flies of both sexes and in middle-aged females. AKG-containing diet did not affect cold hardening in young flies, whereas middle-aged flies fed on AKG were more resistant to repeated cold treatments than control ones. Two-day old flies reared on AKG had higher free amino acid level, including that of proline. At 24-day age, AKG-fed females but not males had higher levels of free amino acids and glucose, and higher total antioxidant capacity than control ones. We conclude that both the enhancement of antioxidant capacity and synthesis of amino acids can contribute to AKG-promoted reduction in CCRT. However, since dietary AKG enhanced locomotor activity and resistance to repeated cold stresses in middle-aged both males and females, mechanisms of beneficial effects of AKG seem to be more complicated, that is discussed.

The present in vivo study was designed to reveal whether amygdalin is able to cause changes in the endocrine profile and thus alter the key reproductive and physiological functions, using rabbits as a biological model. 40 adult female rabbits were randomly divided into five groups: the control group without any amygdalin administration, two experimental groups received a daily intramuscular injection of amygdalin at dose 0.6 and 3.0 mg kg -1 b.w. and other two groups were fed by crushed apricot seeds at dose 60 and 300 mg kg -1 b.w., mixed with commercial feed over the period of 28 days. The body weight of each experimental animal was recorded weekly during the whole study. Plasma levels of steroid (progesterone, 17 β -estradiol, testosterone), thyroid (triiodothyronine, thyroxine, thyroid-stimulating hormone), as well as anterior pituitary (prolactin, luteinizing hormone) hormones were assessed by ELISA. Intramuscular application of amygdalin did not affect ( P ≥ 0.05) the plasma levels of none of the endocrine regulators selected. Oral form of amygdalin did not induce significant changes in the plasma levels of examined hormones either. Similarly, no clinically noticeable changes in the average body weight of experimental animals were observed. Our findings indicate that intramuscular and oral application of amygdalin did not significantly affect the plasma levels of studied endocrine regulators in experimental rabbits. In this in vivo study, no obvious beneficial or negative effects of amygdalin on the physiological functions of female rabbits were demonstrated. Short-term intake of amygdalin at the recommended doses does not represent risk for animal health.