Wyniki wyszukiwania

1

A simple method for visualization of phenolics exudation by roots of intact lupin plants; the effect of nitrate and pH

100%

Wojtaszek P., Peretiatkowicz M.

Acta Biochimica Polonica

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1992

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tom 39

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nr 4

Phenolics exudation by imbibed seeds and roots of intact lupin plants (Lupinus albus L.) was studied during the first 4 days of growth by a new agar test with specific reagents for phenolics (Gibbs reagent, Naturstoffreagenz A). Comparative studies of the phenolics exudation reveal that legumes exude different phenolics (even if not qualitatively, then at least quantitatively) than oat. The exudation of phenolics starts very quickly after the imbibition of seeds and can be visualized as early as 24 h after sowing. In older seedlings, the exudation of phenolics can be detected along root zones and is influenced by nitrate and pH. At acidic pH, nitrate reduces phenolics exudation, but at pH 7.5 the exudation of phenolics becomes restricted to only some root zones. Nitrate must be present in the rooting media for at least 24 h to cause visible changes in the pattern of exudation at different pH values.

2

Calcium ion presence as a trait of receptivity in tenuinucellar ovules of Galanthus nivalis L.

84%

Chudzik B., Sniezko R.

Acta Biologica Cracoviensia. Series Botanica

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2003

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tom 45

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nr 1

In Galanthus nivalis during the progamic phase, both the embryo sac and somatic cells of the ovule change their ultrastructure and physiology, as observed by light, fluorescence, and electron microscopy. Fresh ovules from buds, opening flowers, and from cross-pollinated flowers were stained in toto to detect pectins, acidic polysaccharides, proteins, lipids, callose, free calcium ions and membrane-bound calcium. These substances were found only in the micropylar part of fertile ovules. All stainings were negative in sterile ovules. In EM, the somatic cells in the micropylar part of the ovule were observed to develop secretion activity. Their exudates passed to the intercellular spaces, mainly to the micropylar canal. The amount of the exudate increased after pollination. Free or loosely bound calcium ions were present in extracellular regions of the micropylar part of fertile ovules. The substances detected in the micropylar exudate of fertile ovules are suggested to support and direct pollen tube growth to the embryo sac.

3

Different sensitivities of unicellular and colonial microcystis strains (Cyanophyceae) to six emergent macrophytes

67%

Zhao J., He X., Sun P., Zhang S.

Polish Journal of Environmental Studies

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2013

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tom 22

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nr 5

The effects of six emergent macrophytes (Typha orientalis, Acorus calamus, Oenanthe javanica, Scirpus validus, Sagittaria sagittifolia, and Pontederia cordata) on the growth of two strain Microcystis aeruginosa were studied under co-culture conditions. And the sensitivities of unicellular and colonial Microcystis strains to six emergent macrophytes were compared using an exudation experiment. Based on laboratory experiments, T. orientalis, A. calamus, O. javanica, S. validus, S. sagittifolia, and P. cordata had strong inhibitory effects on growth of unicellular M. aeruginosa, while only A. calamus and P. cordata show obvious growth inhibition on colonial M. aeruginosa. When the biomass density was 20 g FW·L⁻¹, the growth inhibition rate of unicellular M. aeruginosa can exceed 90% for all of the six emergent macrophytes. When macrophytes coexisted with the colonial M. aeruginosa, only A. calamus, P. cordata, and S. sagittifolia showed the growth inhibition of algae. Maximal inhibition of Chl a growth was 75% (p<0.05) for A. calamus, 69% (p<0.05) for P. cordata, and 40% for S. sagittifolia at 45 g FW·L⁻¹ on day 15. The results of the exudation experiment indicated that there were no significant differences between control and treatment of Chl a concentrations of colonial M. aeruginosa for all of the six macrophyte exudations on days 6 and 12. While after 6 d incubation in 100% and 50% macrophyte exudations (40 g FW·L⁻¹), the cell densities of unicellular M. aeruginosa in control were obviously higher than all those in treatment (p < 0.05). The maximal algal growth inhibition (89.62%) of unicellular M. aeruginosa was achieved in 100% exudation of A. calamus on day 6 (p < 0.05). So according to the results of exudation experiments, the unicellular M. aeruginosa was more sensitive than the colonial strain to six emergent macrophytes. And this different sensitivity between Microcystis species probably correlated positively with colony size.

Ograniczanie wyników

1 Acta Biochimica Polonica

1 Acta Biologica Cracoviensia. Series Botanica

1 Polish Journal of Environmental Studies

1 Chudzik B.

1 He X.

1 Peretiatkowicz M.

1 Sniezko R.

1 Sun P.

1 Wojtaszek P.

1 Zhang S.

1 Zhao J.

1 2013

1 2003

1 1992

A simple method for visualization of phenolics exudation by roots of intact lupin plants; the effect of nitrate and pH

Calcium ion presence as a trait of receptivity in tenuinucellar ovules of Galanthus nivalis L.

Different sensitivities of unicellular and colonial microcystis strains (Cyanophyceae) to six emergent macrophytes