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1

Studies on the mechanism of mutagenicity and genotoxicity induced by dihydralazine

100%

Chlopkiewicz B., Ejchart A., Marczewska J.

Acta Biochimica Polonica

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1995

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tom 42

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nr 3

Dihydralazine was found to be mutagenic towards S. typhimurium TA1537, TA97, TA1538 and TA98 and genotoxic towards E. coli PQ37. Using the nitro blue tetrazolium reduction method we have found that dihydralazine can generate active oxygen species. The possible role of active oxygen species in mutagenicity (Ames test) and genotoxicity (SOS Chromotest) of dihydralazine was studied by testing the influence of the different active oxygen species scavengers on these two processes. Of the active oxygen scavengers tested, only superoxide dismutase suppressed partially the mutagenic and genotoxic activity of dihydralazine. This result seems to indicate that superoxide anion play a role in these two biological events.

2

Generation of active oxygen species in yew shoot blight of Taxus baccata L. caused by Pestalotiopsis funerea desm

88%

Rybus-Zajac M., Mietkiewicz M.

Polish Journal of Natural Sciences. Supplement

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2003

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tom 01

3

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Comparison of resistance to water stress of two wheat cultivars

63%

Prochazkova D., Wilhelmova N.

Zeszyty Problemowe Postępów Nauk Rolniczych

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2002

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tom 481

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nr 1

The effects of drought stress on changes in the relative water content, in levels of photochemical efficiency and chlorophyll content and in activities of antioxidative enzymes of second leaves of winter wheat (Triticum aestivum L.) cultivars Mironovská and Estica were compared. In one set, control plants were regularly watered, the other set of plant was subjected to water deficit period since 11th day to 18th day of plants life-span. The activity of all antioxidative enzymes and content of β-carotene increased, relative water content, total chlorophyll content and photochemical efficiency decreased after treatment in both cultivars. In the case of Estica the values of antioxidative enzymes activity was higher than in the case of Mironovská. It is therefore possible to assume that Estika is capable of dealing with higher levels of active oxygen species created during drought stress.This might enabled it compensate the effects of drought stres more effectively.

4

Changes in catalase and peroxidase activities in forage grasses as response to Microdochium nivale

63%

Marzec K.

Acta Physiologiae Plantarum

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2007

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tom 29

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nr 1 Suppl.

5

Kinobeon A, purified from cultured safflower cells, is a novel and potent singlet oxygen quencher

63%

Kambayashi Y., Takekoshi S., Nakano M., Shibamori M., Hitomi Y., Ogino K.

Acta Biochimica Polonica

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2005

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tom 52

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nr 4

We recently reported that kinobeon A, produced from safflower cells, suppressed the free radical-induced damage of cell and microsomal membranes. In the present study, we investigated whether kinobeon A quenches singlet oxygen, another important active oxygen species. Kinobeon A inhibited the singlet oxygen-induced oxidation of squalene. The second-order rate constant between singlet oxygen and kinobeon A was 1.15 × 1010 M-1s-1 in methanol containing 10% dimethyl sulfoxide at 37°C. Those of α-tocopherol and β-carotene, which are known potent singlet oxygen quenchers, were 4.45 × 108 M-1s-1 and 1.26 × 1010 M-1s-1, respectively. When kinobeon A was incubated with a thermolytic singlet oxygen generator, its concentration decreased. However, this change was extremely small compared to the amount of singlet oxygen formed and the inhibitory effect of kinobeon A on squalene oxidation by singlet oxygen. In conclusion, kinobeon A was a strong singlet oxygen quencher. It reacted chemically with singlet oxygen, but it was physical quenching that was mainly responsible for the elimination of singlet oxygen by kinobeon A. Kinobeon A is expected to have a preventive effect on singlet oxygen-related diseases of the skin or eyes.

6

Molecular modeling of singlet-oxygen binding to anthraquinones in relation to the peroxidating activity of antitumor anthraquinone drugs

63%

Liwo A., Jeziorek D., Ossowski T., Dyl D., Tempczyk A., Tarasiuk J., Nowacka M., Borowski E., Woznicki W.

Acta Biochimica Polonica

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1995

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tom 42

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nr 4

Anthraquinone derivatives are important anti-cancer drugs possessing, however, undesirable peroxidating and, in consequence, cardiotoxic properties. This results from the mediation by these compounds of the one-electron reduction processes of the oxygen molecule, which produces the highly toxic superoxide anion radical and other active oxygen species. This article summarizes the results of our studies on the molecular aspects of the mechanism of anthraquinone-mediated peroxidation which were carried out using enzymatic-assay, electrochemical, and quantum-mechanical methods.

7

Oxidative events accompanying regeneration processes from in vitro cultured hypocotyls of Mesembryanthemum crystallinum L.

63%

Libik M., Czechowska M., Sliwa I., Pater B., Miszalski Z.

Biological Letters

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2005

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tom 42

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nr 2 Spec.Vol.

8

Changes in catalase and peroxidase activities in chosen forage grasses as a response to Microdochium nivale infection

51%

Marzec K., Plazek A.

Zeszyty Problemowe Postępów Nauk Rolniczych

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2008

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tom 524

The aim of the study was to investigate changes in activity of catalase (CAT) and non-specific peroxidase (PX) in leaves of chosen forage grasses during pathogenesis evoked by Microdochium nivale and to state if the activity of these antioxidants could be recognized as the physiological marker of grass resistance to snow mould. Plants of Festuca pratensis cv. Skra, Festuca arundinacea cv. Kord, Festulolium braunii cv. Felopa, Lolium multiflorum cv. Tur, Lolium perenne cvs Darius and Taya were hardened and then inoculated by snow mould caused by Microdochium nivale. The leaf samples were collected prior to infection, and 2, 4 and 8 days after inoculation. Each plant cultivars demonstrated specific activity of catalase and non-specific peroxidase. Skra and Taya recognized as more tolerant to M. nivale showed inhibited CAT activity during pathogenesis, however the infected plants of cv. Skra were characterized by a lower CAT activity than the control during the whole time of experiment, while cv. T aya 4 and 8 days after inoculation. No universal pattern of PX activity for all studied plant species was found. Skra cv. demonstrated the highest PX activity especially 8 days after the infection. Grass resistance to M. nivale may be evaluated on the basis of activity of both catalase and non-specific peroxidase. Plants more resistant to this disease are characte-rized by inhibited activity of catalase and activation of cell wall peroxidases.

9

Ascorbate and ascorbate peroxidase as factors of the cell homeostasis in the phosphate deficiency

51%

Kozlowska-Szerenos B., Jablonska A., Oldakowska S., Maleszewski S.

Biological Letters

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2005

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tom 42

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nr 2 Spec.Vol.

10

Resistance mechanisms of winter cereals and forage grasses to snow mould fungi

38%

Marzec K., Plazek A.

Zeszyty Problemowe Postępów Nauk Rolniczych

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2008

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tom 524

Winter survival of cereals and grasses depends mainly on plant resistance to low temperature and to snow mould fungi. To persist winter plants have to be tolerant to different kind of stresses: abiotic such as low temperature, long-term snow and ice cover, freeze-induced plant desiccation or frequent freezing and thawing, and biotic - many species of snow mould fungi. During the cold acclimation, cereals and grasses become more resistant to both stresses: cold and snow mould. Earlier seeded plants with a greater number of crowns are more resistant to snow mould. Infection caused by snow mould induces a complex plant response, including such processes as the synthesis of PR (pathogenesis-related) proteins (chitinase and β-1,3-glucanas), production of active oxygen species (AOS), synthesis of phenolics, phyotalexins, accumulation of callosis and soluble carbohydrates, and a decrease of water potential. In the paper the most common defence mechanisms against snow mould pathogens are discussed.

Ograniczanie wyników

Studies on the mechanism of mutagenicity and genotoxicity induced by dihydralazine

Generation of active oxygen species in yew shoot blight of Taxus baccata L. caused by Pestalotiopsis funerea desm

Comparison of resistance to water stress of two wheat cultivars

Changes in catalase and peroxidase activities in forage grasses as response to Microdochium nivale

Kinobeon A, purified from cultured safflower cells, is a novel and potent singlet oxygen quencher

Molecular modeling of singlet-oxygen binding to anthraquinones in relation to the peroxidating activity of antitumor anthraquinone drugs

Oxidative events accompanying regeneration processes from in vitro cultured hypocotyls of Mesembryanthemum crystallinum L.

Changes in catalase and peroxidase activities in chosen forage grasses as a response to Microdochium nivale infection

Ascorbate and ascorbate peroxidase as factors of the cell homeostasis in the phosphate deficiency

Resistance mechanisms of winter cereals and forage grasses to snow mould fungi