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1

Changes in the long-lasting delaved luminescence from Nitellopsis obtusa cells, as induced by biologically active substances

100%
Jaskowska A., Borc R., Dudziak A., Gospodarek M., Zolnierczuk R.
Cellular and Molecular Biology Letters
|
2002
|
tom 07
|
nr Suppl.
2

Dependence of oscillatory changes in electrical resistance of Nitellopsis obtuca cell membranes on the vegetation season

86%
Spiewla E.
Acta Societatis Botanicorum Poloniae
|
1995
|
tom 64
|
nr 4
375-377
3

Dependence of ampitude oscillatory changes in potential and electrical resistance of Nitellopsis obtusa cell membranes on the stage of cell development

86%
Spiewla E.
Acta Societatis Botanicorum Poloniae
|
1994
|
tom 63
|
nr 2
187-189
4

Electrical potentials and its fluctuations in nodal cells of Nitellopsis obtusa

86%
Spiewla E., Jaskowska A., Segit P., Tokarska-Schlattner M.
Acta Societatis Botanicorum Poloniae
|
1995
|
tom 64
|
nr 4
379-383
5

The effect of cadmium on the vital activity of Nitellopsis obtusa cells

86%
Tyrawska D., Grochala K., Kowszylo Z., Manusadzianas L.
Polskie Archiwum Hydrobiologii
|
1994
|
tom 41
|
nr 4
451-463
6

An investigation of the adaptation of Characeae plants to temperature changes by means of ultraweak luminescence

86%
Borc R., Dudziak A., Jaskowska A., Spiewla E.
Cellular and Molecular Biology Letters
|
2002
|
tom 07
|
nr Suppl.
7

Effect of triphenyllead chloride on the resting potential and electrical conductance of Nitellopsis obtusa membrane

86%
Trela Z., Radecki J., Przestalski S.
Polish Journal of Environmental Studies
|
1997
|
tom 06
|
nr 4
The effect of triphenyllead chloride on membrane potential and electrical conductance of internodal cells of the alga Nitellopsis obtusa was studied. It was found that the compound studied, when present at 50 μM concentration, caused membrane depolarization and increased electrical conductance. The effect is, however, observed only after 0-30 min incubation, which may be due to the cumulation of triphenyllead in the cell wall before direct contact with the plasma membrane could occur. After 30 min incubation in triphenyllead solution the average relative changes in the membrane potential and electric conductance were -0.1±0.04 and 0.33±0.08 (n=12), respectively. These changes may be due to increased permeability of chloride ionsbrought about by the compound's interaction with channel proteins, or increased unspecific leakage of ions induced by a disturbance in the membrane structure.
8

Ramienice Polski polnocno-wschodniej, Nitellopsis obtusa [Desvaux] J.Groves 1919 - krynicznica tepa

72%
Hutorowicz A.
Komunikaty Rybackie
|
1998
|
nr 6
26-27
9

Carbon dynamics in hardwater lake: effect of charophyte biomass on carbonate deposition

72%
Pukacz A., Pelechaty M., Frankowski M.
Polish Journal of Ecology
|
2014
|
tom 62
|
nr 4
The photosynthetic activity of phytoplankton (in pelagial) and macrophytes (in littoral) is considered to be one of the main factors affecting the carbon cycle in lakes. This concerns in particular hardwater ecosystems, where most of the carbon is available in the form of Ca- or Mg-bicarbonates. In such ecosystems charophytes (macroscopic green algae, forming dense meadows) are regarded as the most effective carbonate producer due to the HCO3— utilization and the formation of thick CaCO3 encrustations.Calcium carbonate and biomass production of charophytes were studied in a small and shallow charophyte-dominated Lake Jasne (Western Poland). Fresh and dry weight of plants, percentage contribution of calcium carbonate and production of CaCO3 per 1 m2 were studied at three depths (1, 3 and 5 m) in three sample sites (each sampled area −0.04 m2). Additionally, physical-chemical parameters of water samples were studied. It was found that the dry weight of charophytes and the values of calcium carbonate were similar for all sites but varied for depth of sampling. The dry weight exceeded 2000 g m-2 (average 1165 g m-2) at the most shallow sample sites. CaCO3 encrustations constituted from 39.5% at the depth of 5m, to over 82% of the charophyte dry weight at the depth of 1m. The maximum and average values of carbonates precipitated by charophytes were 1696 g m-2 and 891 g m -2, respectively, and exceeded results reported so far. The results of physical-chemical analyses revealed no statistically significant differences between all the sample sites. Nevertheless, distinct correlations were found between dry weight of charophytes, carbonates precipitated by charophytes and some physical-chemical properties of water from the sample sites. The results highlight the habitat engineering role of charophytes, evidenced in particular by great amounts of biomass influencing sedimentary processes and biogeochemical cycle within littoral zone.
10

Comparing the effect of phytoplankton and a charophyte on calcite precipitation in lake water: experimental approach

72%
Kufel L., Rymuza K.
Polish Journal of Ecology
|
2014
|
tom 62
|
nr 3
Primary producers are able to strongly affect calcium budget in hardwater lakes. The relative contribution of phytoplankton and charophytes to water decalcification (by precipitation of calcium carbonate) is, however, unclear. In this study we checked the effect of natural phytoplankton community and a charophyte (Nitellopsis obtusa) on the decline of calcium concentration in experimental outdoor conditions. The experiment was carried out in original lake water and two variants of enrichment with inorganic nitrogen and phosphorus to test the changing efficiency in decalcification by both primary producers. At low nutrient concentrations, N. obtusa was responsible for calcium decline in original lake water by 12 mg Ca+2 dm–3 during 20 days of experiment. In these conditions the effect of phytoplankton was negligible. In lake water enriched with nutrients, the exponential growth of phytoplankton led to the decrease of calcium concentration from initial 35 mg Ca+2 dm–3 to 9 mg Ca+2 dm–3 in the same time period. The maximum effect of N. obtusa was the same as in original lake water but manifested itself earlier to decline in the end of experiment. Supersaturation of water with calcium carbonate was always more than threefold and saturation index reached 27 in mixed cultures of phytoplankton and N. obtusa in lake water enriched with nutrients. In this context we hypothesise on a possible role of charophytes as nucleation sites necessary for calcite precipitation. Based on our own and literature data we also discuss expected immobilisation of phosphate incorporated in calcite precipitated by the growth of phytoplankton and N. obtusa.
11

Influence of humic acids [HA], DCMU, and light on the ultraweak luminescence [UL] of Characeae cells

72%
Milczarek I., Jaskowska A., Golebiowska D.
Electronic Journal of Polish Agricultural Universities. Series Environmental Development
|
2003
|
tom 06
|
nr 2
Ultraweak luminescence (UL) within the visible range accompanies physiological processes taking place in Native non-stressed Nitellopsis Obtusa cells. Intensity of UL emission is several times higher than the intensity of an environmental medium. The influence of Humic acid (HA), diuron-urea herbicide (DCMU) and photosynthetic active radiation (PAR) on UL intensity and spectral composition for algae cells was investigated. Measurements were made both in neutral and reactive media. An artificial pond water (APW) served as a neutral medium. Algae cells in APW were used as the control samples. Concentrations of specific chemical agents were equal to 8·10-2mg·mL-1, 4.2·10-2 mmol·L-1 for HA and DCMU, respectively, whereas PAR intensity reached 900 µE·s-1·m-2. The influence of HA and light on UL intensity was studied.
12

Ureolytic activity of Nitellopsis obtusa [Characeae]

72%
Karcz W., Krajewska B., Zaborska W.
Acta Physiologiae Plantarum
|
2001
|
tom 23
|
nr 3
13

Wpływ jonów kadmu na reakcję fotoelektryczną komórek Nitellopsis obtusa

71%
Stolarek J., Kurtyka R., Karcz W., Mroczkowska-Badner E., Malkowski E.
Acta Biologica Silesiana
|
1991
|
tom 17
14

Zależności wewnątrzbiocenotyczne w fitocenozach zespołu krynicznicy tępej Nitellopsidetum obtusae na tle cech jakości wody w jeziorach Ziemi Lubuskiej

58%
Styperek L., Pelechaty M., Pukacz A.
Chrońmy Przyrodę Ojczystą
|
2014
|
tom 70
|
nr 2
Ramienice (Characeae), jako gatunki wrażliwe na zmiany środowiska wodnego, mogą być bardzo dobrymi wskaźnikami jego stanu, zwłaszcza gdy tworzą podwodne zbiorowiska, zwane łąkami ramienicowymi. Wykazują, ponadto, znaczący wpływ na jakość wód. W artykule przeanalizowano cechy wód 15 jezior Ziemi Lubuskiej, w których stwierdzono obecność fitocenoz zespołu krynicznicy tępej Nitellopsis obtusa (Desvaux) J. Groves. Analiza składowych głównych (PCA) wykazała, że stężenie azotu ogólnego, wapnia, magnezu, pH oraz morfologia najsilniej wpływają na zróżnicowanie badanych zbiorników. W sezonie letnim 2001–2005 zbadano łącznie 50 fitocenoz wykazując ich obecność w wodach mezotroficznych i mezoeutroficznych. Zależności wewnątrzbiocenotyczne pomiędzy poszczególnymi taksonami były istotne statystycznie. Analiza korelacji rang Spearmana uwidoczniła ujemne zależności pomiędzy dominującą krynicznicą tępą a pokryciem badanych powierzchni przez takie gatunki roślin, jak: rogatek sztywny Ceratophyllum demersum, moczarka kanadyjska Elodea canadensis i mech zdrojek Fontinalis antipyretica. Najsilniejszy negatywny wpływ odnotowano jednak w przypadku ramienicy kruchej Chara fragilis. Ponadto udokumentowano wewnętrzne zróżnicowanie florystyczne i strukturalne zespołu krynicznicy tępej – jednego z najczęściej występujących zbiorowisk ramienicowych, zarówno na badanym obszarze, jak i w całym kraju
15

Adaptation of the photosynthetic apparatus of Nitellopsis obtusa to changing light intensity at the molecular level: different pathways of a singlet excitation quenching

58%
Gruszecki W. I., Gospodarek M., Jaskowska A., Spiewla E.
Acta Physiologiae Plantarum
|
2006
|
tom 28
|
nr 2
The effect of pro longed illumination (60 min) with photosynthetically active monochromatic radiation of low intensity (3 μmol-m⁻² ·s⁻¹) and high intensity (60 mmol m⁻² ·s⁻¹), corresponding to the physiological conditions and light stress conditions, respectively, was studied in the algae Nitellopsis obtusa. Illumination of Nitellopsis obtusa cells with strong light was associated with activation of the xanthophyll cycle, manifested by the deepoxidation of violaxanthin and accumulation of antheraxanthin and zeaxanthin. At the same time, the efficient singlet excitation quenching in the photosynthetic apparatus was activated, as demonstrated by the decrease in the intensity of the chlorophyll a fluorescence emission by ca 50 %. The difference of the fluorescence excitation spectra recorded before and after the light treatment match the difference absorption spectrum of the xanthophyll cycle pigments. The illumination with low light intensity resulted also in the chlorophyll a fluorescence quenching but the effect was very small (less than 10 %). The fluorescence quenching is interpreted in terms of the energy transfer between the Qy energy level of chlorophyll a and the 2¹Ag⁻ energy level of zeaxanthin. The singlet energy levels of carotenoids, corresponding to the green spectral region, are also taken into consideration in the interpretation of the excitation energy exchange between the carotenoids and chlorophylls. Possible molecular mechanisms involved in the activation of the strong and the weak excitation quenching, including violaxanthin isomerization, and possible physiological functions of such pathways of energy transfer are discussed.
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