Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 6

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Occurrence of neoxanthin and lutein epoxide cycle in parasitic Cuscuta species

100%
Kruk J., Szymańska R.
Acta Biochimica Polonica
|
2008
|
vol. 55
|
issue 1
183-190
EN
In the present study, xanthophyll composition of eight parasitic Cuscuta species under different light conditions was investigated. Neoxanthin was not detected in four of the eight species examined, while in others it occurred at the level of several percent of total xanthophylls. In C. gronovii and C. lupuliformis it was additionally found that the neoxanthin content was considerably stimulated by strong light. In dark-adapted plants, lutein epoxide level amounted to 10-22% of total xanthophylls in only three species, the highest being for C. lupuliformis, while in others it was below 3%, indicating that the lutein epoxide cycle is limited to only certain Cuscuta species. The obtained data also indicate that the presence of the lutein epoxide cycle and of neoxanthin is independent and variable among the Cuscuta species. The xanthophyll cycle carotenoids violaxanthin, antheraxanthin and zeaxanthin were identified in all the examined species and occurred at the level found in other higher plants. The xanthophyll and lutein epoxide cycle pigments showed typical response to high light stress. The obtained results also suggest that the ability of higher plants to synthesize lutein epoxide probably does not depend on the substrate specificity of zeaxanthin epoxidase but on the availability of lutein for the enzyme.
2
Publication available in full text mode
Content available

Fotosynteza u eukariontów, czyli krótka historia endosymbiozy

100%
Nowicka B., Kruk J.
Kosmos
|
2016
|
vol. 65
|
issue 2
187-195
PL
Fotosyntetyczne organizmy eukariotyczne odgrywają kluczową rolę w biosferze Ziemi. Na lądzie dominują rośliny wyższe, z tego względu przez stulecia to one właśnie były przedmiotem najintensywniejszych badań. Tymczasem rośliny są zaledwie jedną z wielu grup fotosyntetycznych eukariontów. Nabycie zdolności do przeprowadzania fotosyntezy zaszło niezależnie u przodków kilkunastu innych grup systematycznych. Przedstawiciele części z nich są głównymi producentami biomasy w morzach i oceanach, gdzie wchodzą w skład fitoplanktonu. W niniejszym artykule omówiono rozpowszechnienie fotosyntezy u eukariontów oraz procesy, które doprowadziły do nabycia przez nie zdolności do jej przeprowadzania. Z uwagi na to, iż w literaturze przedmiotu najwięcej uwagi poświęcono roślinom wyższym i zielenicom, w niniejszym artykule skupiono się na przedstawicielach pozostałych grup fotosyntetycznych eukariontów.
EN
Photosynthetic organisms belonging to the kingdom of eukaryota fulfill significant roles in the biosphere. Higher plants dominate on the land, therefore this group has been most intensively studied. However, plants are only one group of the many other groups of photosynthetic eukaryota. The ability to perform photosynthesis was acquired independently by ancestors of several eukaryotic lineages. Some of these lineages are major primary producers in the oceans. In this article, occurrence of photosynthesis in eukaryota, as well as processes responsible for acquirement of plastids are described. The authors decided to concentrate on systematic groups other than higher plants and green algae, because photosynthesis of last two has been widely described in the literature.
3
Content available remote

Fitosterole - występowanie i znaczenie dla człowieka

100%
Szymańska R., Kruk J.
Kosmos
|
2007
|
vol. 56
|
issue 1-2
107-114
EN
Phytosterols (plant sterols) are compounds widely distributed among the plant kingdom occurring in the highest amounts in plant oils. They can be classified into two groups: sterols and stanols, which have fully saturated sterol rings. The main interest in phytosterols is due to their cholesterol-lowering effect in human plasma which is important for their application in different food products as natural drugs protecting against arteriosclerosis and heart diseases. Moreover, it has been shown that phytosterols show also anticancer action against colon, breast and prostate cancer and have antioxidation properties.
4
Content available remote

Identification of hydroxy-plastochromanol in Arabidopsis leaves

100%
Szymańska R., Kruk J.
Acta Biochimica Polonica
|
2010
|
vol. 57
|
issue 1
105-108
EN
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.
5
Content available remote

Reaktywne formy tlenu w roślinach - więcej niż trucizna

100%
Nowicka B., Kruk J.
Kosmos
|
2013
|
vol. 62
|
issue 4
583-596
PL
Reaktywne formy tlenu (ROS) odgrywają istotną rolę w roślinach, nie tylko jako toksyczne produkty uboczne, powstające podczas metabolizmu tlenowego, ale też związki uczestniczące w regulacji rozwoju i odpowiedzi na stres. W niniejszej pracy przeglądowej przedstawiono rodzaje ROS, powodowane przez nie uszkodzenia, miejsca ich powstawania i detoksykacji w komórce roślinnej. Sygnałowa funkcja ROS w ostatnich latach stała się przedmiotem intensywnych badań. Wykazano, iż ROS uczestniczą w regulacji odpowiedzi na rozmaite rodzaje stresu abiotycznego, m.in. światło o wysokim natężeniu, wysoką lub niską temperaturę, czy zasolenie. Ponadto, są one ważnym elementem odpowiedzi na atak patogenu, pełniąc zarówno funkcję sygnałową, jak i efektorową. Wiadomo, że ROS odgrywają rolę w regulacji rozwoju roślin, w tym wzrostu korzeni, blaszki liściowej, czy łagiewki pyłkowej. Molekularny mechanizm działania ROS wciąż jest słabo poznany. Do tej pory poznano niektóre elementy kaskad sygnałowych, w tym regulowane przez ROS kinazy, fosfatazy oraz szereg czynników transkrypcyjnych. W niniejszej pracy omówiono wyżej wymienione zagadnienia w oparciu o najnowsze doniesienia literaturowe.
EN
Reactive oxygen species (ROS) play a number of important roles in plants, not only as a toxic byproducts of oxygen metabolism, but also as regulators of development and stress responses. In the present review, types of ROS, their chemical reactivity, sites of their generation and detoxification in plant cells are described. Recently, signaling function of ROS has been intensively examined. It was shown, that ROS participate in the regulation of responses to various types of abiotic stress, like high light, high or low temperature or salt stress. Moreover, ROS are important in response to pathogen attack, acting as signaling molecules, but also as toxic agents to pathogens. It is also known, that ROS participate in the regulation of development processes, such as growth of roots, leaves and pollen tubes. Molecular mechanism of ROS action is still poorly known. Up to date, some elements of signaling cascades were identified, like kinases, phosphatases and transcription factors. In this paper, signaling functions of ROS been described in the light of recent literature data.
6
Content available remote

Witamina e - metabolizm i funkcje

81%
Szymańska R., Nowicka B., Kruk J.
Kosmos
|
2009
|
vol. 58
|
issue 1-2
199-210
EN
Vitamin E belongs to the group of chemical compounds called tocochromanol. It is synthesized exclusively by plants but fulfills also numerous important functions in humans. In the present article the occurrence and biosynthesis of vitamin E in plants have been described, as well as its diverse functions in plants including antioxidant action. Moreover, the metabolism of vitamin E and physiological significance in humans have been presented.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.