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1

Sensitivity of terrestrial cyanobacteria to light and sulphite stress

100%

Miszalski Z., Budel B., Luttge U.

Polish Journal of Environmental Studies

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1995

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tom 04

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nr 4

Under light stress of 1000 /imol s-1m-2 (λ=400 - 700 nm) for 140 min cyanobacteria mats of "tintenstrich" formations on limestone rocks of Kobylaňska-Valley, west of Cracow, Poland showed reduction of the potential and eiTective quantum yield variables ∆F/Fm' and Fv/Fm3, respectively of PSII and the samples first recovered partly after six days. Also, the Fo level, known to be affected by environmental stress, increased rapidly due to strong light intensity. Sulphite stress (100 mM) was first manifested very clearly after a long, 15h exposure, but not during the first 40 min. Thus, these terrestrial cyanobacteria appear to be less sensitive to sulphite stress than eucaryotic algae, lichens and higher plants studied so far. It is not yet clear if this is due to i) special adaptation of these free living terrestrial cyanobacteria growing in a heavily polluted area, ii) buffering capacity of the limestone support, or iii) other factors.

2

The threshold of photoinhibition as an indicator of stress state of plants

86%

Topchiy N. M., Zolotareva E. K.

Acta Physiologiae Plantarum

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2007

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tom 29

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nr 1 Suppl.

3

Identification of hydroxy-plastochromanol in Arabidopsis leaves

86%

Szymanska R., Kruk J.

Acta Biochimica Polonica

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2010

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tom 57

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nr 1

105-108

In the present study we have identified hydroxy-plastochromanol in plants for the first time. This compound was found both in low light and high light-grown Arabidopsis plants, however, under high light stress its level was considerably increased. Hydroxy-plastochromanol accumulated also during ageing of leaves of low light-grown plants, similarly as in the case of other prenyllipids. Our results indicate that hydroxy-plastochromanol found in leaves is probably formed as a result of plastochromanol oxidation by singlet oxygen generated in photosystem II during photosynthesis. These data also support the hypothesis that plastochromanol is an efficient antioxidant in vivo, similarly as tocopherols and plastoquinol.

4

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

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2006

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tom 28

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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.

5

Response of antioxidative enzymes to long term cold and light stress of spruce seedlings

58%

Kaminska-Rozek E., Pukacka P. M.

Biological Letters

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2005

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tom 42

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nr 2 Spec.Vol.

6

Two-dimensional electrophoresis of thylakoid proteins from yellow lupin subjected to thermal and light stress

58%

Oczkowski M., Kalinowski A., Bartkowiak S., Augustyniak A.

Biological Bulletin of Poznań

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1997

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tom 34

7

Activity of the xantophyll cycle in cadmium-treated Phaseolus coccineus and Secale cereale plants

58%

Niedzwiecki D., Skorzynska-Polit E., Drazkiewicz M., Grudzinski W., Janik E., Krupa Z., Gruszecki W. I.

Biological Letters

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2005

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tom 42

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nr 2 Spec.Vol.

8

Identyfikacja cDNA i charakterystyka genu OHP2 (One Helix Protein 2) Pharbitis nil Choisy

51%

Stawski K., Dabrowska G., Goc A.

Zeszyty Problemowe Postępów Nauk Rolniczych

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2008

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tom 524

Rodzina białek OHP (ang. One Helix Protein) roślin wyższych, jest jądrowo kodowaną grupą białek indukowanych stresem świetlnym, gromadzonych w błonach tylakoidów, spokrewnionych z rodziną białek wiążących chlorofil LHC (ang. LightHarvesting Complex). Przepisuje się im funkcje ochronną przed fotozniszczeniem. W celu lepszego poznania ewolucji i funkcji białek OHP wyizolowaliśmy cDNA genu OHP2 P. nil. Wykazuje ono wysoką homologię do genu OHP2 A. thaliana. PnOHP2 jest przypuszczalnie syntezowany jako peptyd długości 165 aminokwasów, którego N-końcowa część zawiera peptyd sygnałowy typowy dla białek transportowanych do chloroplastu (długości ok. 76 aminokwasów). C-końcowa część białka PnOHP2 posiada transmembranową domenę α-helikalną. Na podstawie sekwencji aminokwasowej genu PnOHP2 rozważamy funkcje tego białka w chloroplaście badanej rośliny.

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