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Effects of trimethyltin on pinocytosis of Dictyostelium discoideum

100%

Michalik M., Kosinska I., Sroka J., Madeja Z., Przestalski S., Korohoda W.

Acta Protozoologica

2001

tom 40

nr 3

Pdr12p-dependent and -independent fluorescein extrusion from baker's yeast cells

80%

Lushchak V., Abrat O., Miedzobrodzki J., Semchyshyn H.

Acta Biochimica Polonica

2008

tom 55

nr 3

595-601

Fluorescein efflux from S. Cerevisiae cells was measured to study the peculiarities of fluorescein transport system, which is important for yeast resistance to certain drugs and weak organic acid preservatives. Glucose-independent and glucose-stimulated fluorescein effluxes were characterized using iodoacetate, cyanide and orthovanadate, inhibitors of glycolysis, electron transport chain, and ATPases, respectively. It is supposed that in glucose-free medium fluorescein extrusion is ATP-dependent and the energy for this efflux is mainly provided by respiration. In glucose-containing medium, glycolysis plays a critical role for extrusion of fluorescein. The results indicate that acetic acid inhibits the fluorescein efflux from yeast cells. The inhibition constant of glucose-stimulated fluorescein efflux is significantly lower in parental strain than in two mutants defective in PDR12 (ABC-transporter Pdr12p) or WAR1 (transcription factor of Pdr12p). It can be suggested that the membrane protein Pdr12 is involved in fluorescein extrusion from the yeast cells, but component(s) other than Pdr12p is (are) also important.

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Physiological activity of ectomycorrhizas in a moderately polluted forest (Ratanica catchment, Southern Poland)

80%

Kieliszewska-Rokicka B., Kurczynska E. U., Leski T.

Dendrobiology

2000

tom 45

Ectomycorrhizas of Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.) were sampled in a mature forest ecosystem exposed for more than 40 years to moderate levels of gaseous and dust pollutants. Soil of the forest site was characterised by low pH and accumulation of heavy metals (Pb, Mn, Zn, Cu, Cd, Fe). Mycorrhizal vitality and enzyme activity of the root-surface and soil acid phosphatase (AcPase) were studied at 17 measurement points (0–5 cm soil depth) in relation to the content of inorganic phosphate (Pi) and aluminium ions (Al3+) in the soil. Anatomy of Scots pine and beech mycorrhizas taken from different measurement points was observed. The concentration of essential nutrients (C, N, P, Ca, Mg) and the ratios Ca/Al, Mg/Al and N/P were analysed in fine roots. High concentrations of Al3+ in the soil (40–118 meq kg-1) and low levels of Pi (12–44 mg P2O5 kg-1) were accompanied by high activity of the root-surface AcPase of pine and beech mycorrhizas (25–67 and 33–86 μmol pNP g-1 fresh weight h-1, respectively) and soil AcPase (6.8–22.4 μmol pNP g-1 dry weight h-1). The results indicate that fine tree roots are undoubtedly under stress as evidenced by a disturbance in P uptake and accumulation. However, the high vitality of mycorrhizas and the high Ca/Al ratio in fine roots suggest that the defence mechanisms of mycorrhizas and the rhizosphere are still able to ameliorate the influence of anthropogenic pollution.

Ograniczanie wyników

1 Acta Biochimica Polonica

1 Acta Protozoologica

1 Dendrobiology

1 Abrat O.

1 Kieliszewska-Rokicka B.

1 Korohoda W.

1 Kosinska I.

1 Kurczynska E. U.

1 Leski T.

1 Lushchak V.

1 Madeja Z.

1 Michalik M.

1 Miedzobrodzki J.

1 Przestalski S.

1 Semchyshyn H.

1 Sroka J.

1 2008

1 2001

1 2000

Wyniki wyszukiwania

Effects of trimethyltin on pinocytosis of Dictyostelium discoideum

Pdr12p-dependent and -independent fluorescein extrusion from baker's yeast cells

Physiological activity of ectomycorrhizas in a moderately polluted forest (Ratanica catchment, Southern Poland)