20 research outputs found

    Trichostatin A Triggers an Embryogenic Transition in Arabidopsis Explants via an Auxin-Related Pathway

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    Auxin is an important regulator of plant ontogenies including embryo development and the exogenous application of this phytohormone has been found to be necessary for the induction of the embryogenic response in plant explants that have been cultured in vitro. However, in the present study, we show that treatment of Arabidopsis explants with trichostatin A (TSA), which is a chemical inhibitor of histone deacetylases, induces somatic embryogenesis (SE) without the exogenous application of auxin. We found that the TSA-treated explants generated somatic embryos that developed efficiently on the adaxial side of the cotyledons, which are the parts of an explant that are involved in auxin-induced SE. A substantial reduction in the activity of histone deacetylase (HDAC) was observed in the TSA-treated explants, thus confirming a histone acetylationrelated mechanism of the TSA-promoted embryogenic response. Unexpectedly, the embryogenic effect of TSA was lower on the auxin-supplemented media and this finding further suggests an auxin-related mechanism of TSA-induced SE. Congruently, we found a significantly increased content of indolic compounds, which is indicative of IAA and an enhanced DR5::GUS signal in the TSA-treated explants. In line with these results, two of the YUCCA genes (YUC1 and YUC10), which are involved in auxin biosynthesis, were found to be distinctly up-regulated during TSA-induced SE and their expression was colocalised with the explant sites that are involved in SE. Beside auxin, ROS were extensively accumulated in response to TSA, thereby indicating that a stress-response is involved in TSA-triggered SE. Relevantly, we showed that the genes encoding the transcription factors (TFs) that have a regulatory function in auxin biosynthesis including LEC1, LEC2, BBM, and stress responses (MYB118) were highly up-regulated in the TSA-treated explants. Collectively, the results provide several pieces of evidence about the similarities between the molecular pathways of SE induction that are triggered by TSA and 2,4-D that involve the activation of the auxin-responsive TF genes that have a regulatory function in auxin biosynthesis and stress responses. The study suggests the involvement of histone acetylation in the auxin-mediated release of the embryogenic program of development in the somatic cells of Arabidopsis

    Risk factors of migraine-related brain white matter hyperintensities: an investigation of 186 patients

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    Brain white matter hyperintensities are more prevalent in migraine patients than in the general population, but the pathogenesis and the risk factors of these hyperintensities are not fully elucidated. The authors analyzed the routine clinical data of 186 migraine patients who were referred to the Outpatient Headache Department of the Department of Neurology, Medical School, University of Pécs, Hungary between 2007 and 2009: 58 patients with white matter hyperintensities and 128 patients without white matter hyperintensities on 3 T MRI. Significant associations between the presence of white matter hyperintensities and longer disease duration (14.4 vs. 19.9 years, p = 0.004), higher headache frequency (4.1 vs. 5.5 attacks/month, p = 0.017), hyperhomocysteinemia (incidence of hyperintensity is 9/9 = 100%, p = 0.009) and thyroid gland dysfunction (incidence of hyperintensity is 8/14 = 57.1%, p = 0.038) were found. These data support the theory that both the disease duration and the attack frequency have a key role in the formation of migraine-related brain white matter hyperintensities, but the effects of comorbid diseases may also contribute to the development of the hyperintensities

    Coalification history of the Upper Carboniferous sediments in the mining area "Janina" in Libiąż (eastern part of the Upper Silesian Coal Basin)

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    Maturity modelling of the Upper Carboniferous sediments has been performed in order to explain the coalification history. Assuming 2000 m eroded overburden of the post-Stephanian sandstones paleoheat flow was 51 mW/m2 in the latest Carboniferous time. The major coalification processes were likely occurred in the latest Carboniferous, and later a Mesozoic overprinting likely due to fluid migration was not significant for the organic matter maturity

    Timing of coalification of the upper carboniferous sediments in the Upper Silesia Coal Basin on the basis of by apatite fission track and helium dating

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    Przeprowadzono datowania za pomocą metody trakowej i helowej dla apatytów z utworów karbońskich w Górnośląskim Zagłębiu Węglowym w celu określenia ram czasowych procesów uwęglenia. Pomierzone centralne wieki trakowe apatytów mieszczą się w przedziale od 259±11 (późny perm) do 103±6 milionów lat (wczesna kreda), a średnia długość traków waha się od 11,7±0,2 do 13,7±0,1 μm. Wszystkie wieki trakowe są młodsze od wieku stratygraficznego analizowanych próbek, wskazując znaczne zaawansowanie procesów diagenetycznych. Próbki z zachodniej i środkowej części GZW mają wieki trakowe od późnego permu do środkowego/późnego triasu (259±11 do 214±10 mln lat). Jednomodalne rozkłady długości traków i ich średnie wartości wskazują na pojedyncze, względnie szybkie zdarzenie postwaryscyjskiego wychładzania do temperatury poniżej 60°C, co jest zgodne ze znaczną erozją postinwersyjną utworów górnokarbońskich po fazie asturyjskiej. W pozostałej części mezozoiku następowało wolniejsze wychładzanie. Próbki ze wschodniej i NE części GZW mają wieki trakowe od późnego triasu do wczesnej kredy (210±10 do 103±6 milionów lat). Charakteryzuje je względnie krótsza średnia długość traków i wyższe odchylenia standardowe, a także w przypadku części próbek bimodalny i/lub mieszany charakter rozkładów długości. Jest to razem wskazówką bardziej złożonej historii termicznej, z długim okresem przebywania w PAZ i możliwym drugim zdarzeniem termicznym. Wieki helowe apatytów w całym basenie są wczesnokredowe (144,1±11 do 108,1±8milionów lat), wskazując raczej na wolne postwaryscyjskie wychładzanie lub możliwe mezozoiczne podgrzanie karbonu do temperatury nie większej niż 60–70°C, które spowodowało częściową dyfuzję helu i odmłodzenie wieków helowych, ale równocześnie nie spowodowało znaczącego zabliźniania traków na większości obszaru GZW. Jedynie w NE części GZW podgrzanie mezozoiczne mogło być nieco wyższe, do temperatury 70–85°C, powodując odmłodzenie wieków trakowych, zwłaszcza przy długim okresie przebywania w PAZ. Mezozoiczny impuls termiczny był przypuszczalnie spowodowany cyrkulacją gorących roztworów związaną z procesami ekstensji. Powyższe zakresy temperatur i czas ich występowania świadczą, że uwęglenie materii organicznej w GZW nastąpiło zasadniczo z końcem okresu karbońskiego.The apatite fission track and helium dating were used to provide a temporal framework for the coal rank data in the Upper Silesia Coal Basin. Measured apatite fission–track (AFT) central ages from sandstones and tonsteins in the USCB range from 259±11 (Permian) to 103±6 Ma (Early Cretaceous), with mean track lengths ranging from 11.7±0.2 to 13.7±0.1 μm. All AFT ages are younger than sample stratigraphic ages, indicating substantial post–depositional annealing. Samples from the western and central part of the USCB yield AFT ages of Permian to Late Triassic (259±11 to 214±10 Ma). Mean track lengths and unimodal track length distributions of these samples are indicative of a single relatively rapid Variscan cooling event to below 60°C consistent with erosion during the Asturian inversion of the basin. This was followed by slower cooling during the Mesozoic. The samples from the eastern and NE part of the USCB have AFT ages from Late Triassic to Early Cretaceous (210±10 Ma to 103±6 Ma). The relatively shorter mean track length and higher standard deviation, combined with a bimodal and/or mixed fission track length distribution in some samples, is indicative of amore complex thermal history with possibly a thermal event separated by a prolonged period in the PAZ. Apatite helium ages of samples from across the basin range from 144.1±11 to 108.1±8Ma (Early Cretaceous) indicating rather slow, post–Variscan inversion cooling or the possible mid–Mesozoic re–heating where temperatures reached only to 60–70°C. It was high enough for partial He loss from the apatite but not enough to anneal fission tracks in the most areas of the USCB. Only in the NE part of the USCB Mid–Mezozoic re-heating could be able to increase temperature to ~70–85°C causing partially resetting AFT (particularly during long stay in PAZ). Mid–Mesozoic re–heating would be caused by a hot fluid circulation related to extensional tectonic development. The timing and temperature range from thermochronological analysis imply that major coalification processes occurred in the latest Carboniferous period

    The Carboniferous-Rotliegend petroleum system in the German-Dutch part of the basin – implications for natural gas exploration in the Polish part of the Rotliegend basin

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    System naftowy karbon–czerwony spągowiec w niemiecko-holenderskiej części basenu wykazuje szereg podobieństw i różnic w stosunku do polskiej części basenu. Głębokości występowania złóż gazu w niemiecko-holenderskiej części basenu są większe (1000–5300 m) niż w polskiej (1000–3700 m) i do 4000 m w strefach gazu zamkniętego (tight gas). Gazy wykazują duże zróżnicowanie składu chemicznego, jak i parametrów fizycznych. Średnia zawartość metanu w niemiecko-holenderskiej części basenu waha się w przedziale 30–95%, rosnąc szybko w kierunku zachodnim, natomiast w polskiej części basenu wynosi od około kilkunastu do około 90%, wykazując jednak duże zróżnicowanie w poszczególnych strefach. Gazy zakumulowane głównie w czerwonym spągowcu były wygenerowane przez skały macierzyste karbonu górnego (głównie pokłady westfalskich węgli kamiennych) w niemiecko-holenderskiej części basenu, a podrzędnie jedynie przez dolnokarbońskie skały. Basen niemiecko-holenderski był rozcięty przez liczne mezozoiczne uskoki, które przyczyniły się do powstania szeregu zrębów i rowów tektonicznych. Spowodowało to w efekcie zróżnicowanie głębokości pogrążenia i czasu występowania procesów generowania, migracji i akumulacji gazu, oraz zróżnicowanie szeregu pokarbońskich skał zbiornikowych i uszczelniających. Procesy generowania migracji i akumulacji gazów przebiegały wieloetapowo: od późnego karbonu aż do neogenu włącznie.Carboniferous-Rotliegend Petroleum System in the German-Dutch part of the South Permian basin shows a number of similarities and differences in relation to the Polish part of the basin. Depth of occurrence of gas deposits in the German-Dutch part of the basin are larger (~1000–5300 m) than in Poland (~1000–3700 m) with the maximum of up to 4000 m in the tight gas zone. Gases show significant variation of chemical composition and physical parameters. The average methane content in the German-Dutch part of the basin ranges from 30 to 95% rising rapidly towards the west, whilst in the Polish part, the average methane content varies significantly in different areas of the basin (from several up to 90%). Gases that accumulated mainly in the Rotliegend, were generated predominantly by Westphalian source rocks (bituminous coals) in the German-Dutch part of the basin, and only subordinately by Lower Carboniferous source rocks. German-Dutch basin was dissected by numerous Mesozoic faults, associated with horsts, grabens, and platforms. It contributed to the differentiation of burial depth and timing of the generation processes, to the migration and accumulation of gas, and to the diversification of a number of post-Carboniferous reservoir rocks and seals. The processes of gas generation, migration and accumulation included several stages: from Late Carboniferous through Neogene

    Trace element geochemistry of coals from the Southern Cantabrian Zone (NW Spain): preliminary results

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    Bituminous to anthracite coals from three small Stephanian intramontane coal-bearing basins (La Magdalena, Cinera-Matallana and Sabero) located along the Sabero-Gordón fault line strike-slip systems of the Southern Cantabrian Zone (SCZ) were examined. Coal rank expressed as mean vitrinite reflectance values of these Stephanian coals is in the range 0.72-3.96%. The vitrinite maceral group exceeds 72 vol. % in all of the coals. The coals are characterized by relatively variable contents of mineral matter and coal-ash. The mineral matter comprises, in the main, clay minerals, carbonates, sulphides and quartz. The coals exhibit medium-high concentrations (see for comparison Ronov et al. 1990; Kabata-Pendias, Pendias 1999; Ketris, Yudovich 2009) of the following elements (in ppm): ΣREE (53-205), Ba (300-900), As (11-57), Zn (<50-150), Cr (10-160), Rb (50- 145), Co (5-26), Sc (2-24.6), Ce (17-99), Yb (1.3-4.5), Th (2.4-11.9) and U (1.1-8.1), Br (<1-14), Cs (<2-9), Eu (<0,3-1.5), Lu (0.11-0.85) and Sb (0.8-4.8), and relatively low concentrations of Sm (0.6-6.6) and Ta (<1-2). They are also characterised by relatively high Th/U values (1.31-2.29). LREE/HREE values fall in the range 24-44 (average - 30). In contrast, concentrations of Au, Ag, Hg, Ir, Ni, Se, Sn, Sr, and W are below detection limits for the applied INAA method. As the concentrations of elements are significantly higher in coal-ash, most are likely related to mineral matter in the coals

    Gas generation in Carboniferous source rocks of the Variscan foreland basin : implications for a charge history of Rotliegend deposits with natural gases

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    Numerical modelling of the Carboniferous–Permian petroleum system in the Polish Basin was carried out using PetroMod software. The Carboniferous source rocks contain organic matter mostly of a humic nature (gas-prone Type III kerogen). Subordinately, only in the Lower Carboniferous deposits, kerogen of algal marine origin and mixed Type II/III kerogen occur. The quantity of dispersed organic matter is variable, but usually below 2% TOC. In the Carboniferous section, a progressive increase in the maturity of organic matter with depth was observed, from approximately 0.5% Rr at the top of the Westphalian in marginal parts of the Carboniferous basin to over 5.0% Rr at the bottom of the Lower Carboniferous in the eastern Fore-Sudetic Homocline. The thermo- genic generation of hydrocarbons continued from the late Westphalian (eastern Fore-Sudetic Homocline and partly Pomerania) throughout the Mesozoic, up to the Late Cretaceous. The advancement of this process is va- riable in different parts of the Carboniferous basin, reaching up to 100% of kerogen transformation in the zones of maximum maturity of organic matter. However, the most intensive periods of gas generation and migration were the Late Triassic and the Late Jurassic. The most prospective areas are located NE of Poznań–Kalisz line and SW of Poznań
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