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Wyszukujesz frazę "Arendt, R." wg kryterium: Autor


Wyświetlanie 1-2 z 2
Tytuł:
Phenolic compounds and properties of antioxidants in grapevine roots [Vitis vinifera L.] under low-temperature stress followed by recovery
Autorzy:
Weidner, S
Kordala, E.
Brosowska-Arendt, W.
Karamac, M.
Kosinska, A.
Amarowicz, R.
Powiązania:
https://bibliotekanauki.pl/articles/57473.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
oxidative stress
environment condition
plant growth
root
Vitis vinifera
phenolic compound
chill stress
plant development
grape-vine
antioxidative system
Opis:
The research has been performed on roots of Vitis vinifera, cv. Himrod, obtained from seedlings grown under chill stress conditions (+10oC in the day and +7oC at night), under optimum conditions (+25oC in the day and +18oC at night) and from seedling which underwent a recover period after the chill stress treatment. The purpose of the study has been to determine quantitative and qualitative changes in phenolic compounds as well as to demonstrate changes in antiradical properties of extracts from grapevine roots, which appeared as a result of chill stress and during recovery under the optimum conditions following the stress. Phenolic compounds from grapevine roots were extracted using 80% acetone. The total content of phenolics was determined by colorimetry. The content of tannins was tested by precipitation with bovine serum albumin. The reducing power as well as DPPH• free radical and ABTS+• cation radical scavenging activity of the extracts were also tested. In order to identify phenolic compounds present in the extracts the RP-HPLC technique was employed. The tested material was found to contain tannins and three identified phenolic acids: ferulic, caffeic and p-coumaric ones. The latter occurred in the highest concentrations (from 4.46 to 6.28 µg/g fresh matter). Ferulic acid appeared in smaller amounts (from 1.68 to 2.65 µg/g fresh matter), followed by caffeic acid (from 0.87 to 1.55 µg/g fresh matter). Significantly less total phenolic compounds occurred in roots of seedlings subjected to chill stress. However, the total content of these compounds increased significantly in roots of plants which underwent recovery after chill stress. Concentration of tannins was determined by two methods. The content of condensed tannins was depressed in roots as a result of low temperature stress, whereas the content of condensed and hydrolysing tannins (determined via the BSA method) rose under chill stress conditions. A significant increase in tannins in root extracts (determined with both methods) was found during the recovery process after the stress. The three identified phenolic acids appeared in grapevine roots as ester-bound compounds. It has been demonstrated that the content of phenolic acids significantly fell as a result of low temperatures, but increased during recovery after chill stress. The weakest ability to scavenge DPPH• and ABTS+• free radicals as well as the reducing power were shown by the extract obtained from grapevine roots from the seedlings subjected to chill stress. Both free radical scavenging activity and reducing power were observed to increase considerably during recovery after stress. This seems to prove that during the recovery process following chill stress the synthesis of antioxidative compounds in grapevine roots is much more intensive.
Źródło:
Acta Societatis Botanicorum Poloniae; 2009, 78, 4; 279-286
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of osmotic stress and post-stress recovery on the content of phenolics and properties of antioxidants in germinating seeds of grapevine Vitis californica
Autorzy:
Weidner, S.
Brosowska-Arendt, W.
Szczechura, W.
Karamac, M.
Kosinska, A.
Amarowicz, R.
Powiązania:
https://bibliotekanauki.pl/articles/57688.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
osmotic stress
post-stress recovery
phenolic compound content
antioxidative property
germinating seed
seed
grapevine
Vitis californica
antioxidative system
oxidative stress
environmental stress
plant stress
Opis:
The tested material consisted of grapevine Vitis californica stratified seeds germinated under optimum conditions (+25°C in water), under osmotic stress (-0.2 MPa in PEG solution) and submitted to recovery after stress (+25°C in water). The germinating seeds were determined to contain tannins, catechins and the following phenolic acids: gallic, caffeic, p-coumaric and ferulic. The acids occurred in free, ester- and glycoside-bound forms. The dominant form of phenolic acids was the ester-bound fraction. Gallic acid was the most abundant phenolic acid in germinating seeds, while ferulic acid appeared in the smallest amounts. Our analysis of tannins demonstrated that osmotic stress depressed their concentration. Presence of catechin group compounds such as catechin and epicatechin was also determined. In each sample epicatechin was dominant. The total concentration of catechin increased under stress conditions and declined during post-stress recovery. Catechins are a constituent of tannins and their increase under osmotic stress is most probably caused by the breakdown of some tannins in seeds germinating under stress conditions. Samples submitted to osmotic stress were also found to contain less of total phenolic compounds, whereas in samples which underwent post-stress recovery the total level of phenolic compounds increased. Compared to extracts from seeds germinating under optimum conditions, osmotic stress depressed the capacity of extract to scavenge DPPH● (2,2-diphenyl-1-picrylhydrazyl) and ABTS●+ – 2,2-Azino-bis (3-etylbenzothiazoline-6- -sulfonic acid) free radicals, but the antioxidant activity rose in seeds submitted to recovery after stress. Positive correlation was therefore demonstrated between the total content of phenolic acids in germinating grapevine seeds and the reducing power of extracts obtained from these seeds and their free radical scavenging activity. The results suggest that osmotic stress inhibits the activity of antioxidizing enzymes in germinating grapevine seeds. Thus, the antioxidative defence system is largely blocked under osmotic stress. It seems that a very high oxidoreductive potential in grapevine tissues prior to occurrence of osmotic stress is essential for maintaining proper homeostasis of oxidation and reduction reactions.
Źródło:
Acta Societatis Botanicorum Poloniae; 2011, 80, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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