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51.
52.
Jan Bialczyk Zbigniew Lechowski Dariusz Dziga Ewa Mej 《Journal of plant nutrition》2013,36(1):149-161
ABSTRACT This article presents the effects of nitrate/ammonium (NO3 ?/NH4 +), applied at different proportions to the root media with or without 5 mmol bicarbonate (HCO3 ?), on the yield and chemical composition of tomato fruit. Tomato plants were grown hydroponically (pH 6.9) in glasshouse conditions. The yield of fruit fresh matter from four clusters obtained from plants grown on the medium with NH4 + was about 25% lower than from the plants grown on the medium containing NO3 ? as the nitrogen (N) source. Supplying NO3 ?/NH4 + at a ratio of 4:1 increased the fruit yield by about 20% in comparison with the value recorded for NO3 ??plants. The enrichment of the medium with HCO3 ? stimulated the bearing, while the result depended on the ratio of NO3 ?/NH4 +. A combined treatment of HCO3 ? with NO3 ? or NH4 + in the medium increased yields by about 28% and 11%, respectively, in comparison to plants cultivated without HCO3 ?. The application of NO3 ?/NH4 + at ratios of 4:1 and 1:1 with HCO3 ? increased the respective yields by about 16% and 10% in comparison with plants grown without HCO3 ?. Modifications in the composition of the media affected the accumulation of organic solutions in the fruit. The NH4 + nutrition effected a 20% decrease in the accumulation of reducing sugars in the fruit in comparison to the fruit of plants grown in media with NO3 ?. In the cultivation of plants in media with various NO3 ?/NH4 + proportions the intermediate values of the reduced sugar concentrations were recorded in comparison with the values obtained for NO3 ??plants and NH4 +?plants. The enrichment of media with HCO3 ? increased the concentration of sugars in fruit from about 28% (for NO3 ??plants) to about 10% (for NH4 +?plants). Malate and citrate are the main constituents of carboxylates in tomato fruit. The form of nitrogen applied to the medium did not significantly affect the concentration of carboxylates in fruit. Significant differences in carboxylate concentrations appeared in fruit grown on media enriched with HCO3 ? ions. In comparison with the cultivation without HCO3 ?, increases in the accumulation of carboxylates varied from about 22% to 30% depending on the form of the applied nitrogen. The concentration of amino acids in the fruit of plants grown with NH4 + exceeded that in NO3 ??plants by about 55%. In the plants grown on media of modified NO3 ?/NH4 + proportions, the concentration of amino acids in fruits were positively correlated with the level of NH4 + in the medium. The enrichment of media with HCO3 ? stimulated a further increase in amino acid concentration in fruit by about 9% in NO3 ? plants and about 21% in NH4 + plants compared with the respective control (without HCO3 ?). 相似文献
53.
Procyanidin oligomers from Japanese quince (Chaenomeles japonica) fruit inhibit activity of MMP-2 and MMP-9 metalloproteinases 总被引:1,自引:0,他引:1
Strek M Gorlach S Podsedek A Sosnowska D Koziolkiewicz M Hrabec Z Hrabec E 《Journal of agricultural and food chemistry》2007,55(16):6447-6452
The influence of procyanidin extract from Japanese quince fruit on the activities of matrix metalloproteinases MMP-2 and MMP-9 secreted to culture medium by human peripheral blood mononuclear cells (PBMC) and by human leukemia HL-60 cells was investigated by gelatin zymography. The extract proved to be an effective inhibitor of the enzymes activities (for MMP-2 and MMP-9 secreted by PBMC IC50 = 16-19 microg extract/mL and 22-25 microg extract/mL, respectively). To identify the most effective components of the extract it was fractionated by means of column chromatography on TSKgel Toyopearl HW-40 (S) bed. The obtained fractions were analyzed by TLC, HPLC, and MALDI-TOF MS. Their antioxidant activity was measured as cation radicals ABTS(.+) scavenging efficiency. The fractions VIII-XIV containing oligomers from trimer to hexamer (and probably higher oligomers) appeared to be the most effective inhibitors of MMP-2 and MMP-9 activity (IC50 value close to 4.6 microg total polyphenols/mL). To the best of our knowledge, it is the first report on gelatinase-inhibitory activity of Japanese quince fruit polyphenol extract. We conclude that polyphenols from Japanese quince can be used in cancer chemoprevention, although further studies are needed to elucidate the mechanisms underlying their biological activities. 相似文献
54.
Jarosław G. Paluch Zbigniew Kołodziej Jerzy Skrzyszewski Leszek Bartkowicz Piotr Gruba 《Annals of Forest Science》2016,73(4):1015-1024
Key message
In Abies alba Mill. stands and mixed stands of A. alba and Picea abies L. (H. Karst), microsites neighbouring the trunks of adult trees were more conducive to A. alba regeneration. Although at the stand level, the effect of Fagus sylvatica L. was positive; the local effect of the adult F. sylvatica neighbourhood was insignificant. Hence, forming mixed stands with a fine-grained mosaic of admixed species might better facilitate natural regeneration of A. alba than monospecific stands.Context
The establishment of natural regeneration in Abies alba Mill. stands is a slow, spatially heterogeneous and stochastic process. Recent studies based on inventory data indicate that A. alba more readily regenerates in mixed stands than in monospecific stands.Aims
The objective was to examine how this positive association evidenced at the stand level operates on the scale of microsites with contrasting local species composition and stand density.Methods
In 8 monospecific and 22 mixed stands with Fagus sylvatica L. or Picea abies L. (H. Karst), microsites with a contrasting density of A. alba seedlings were selected and compared in terms of local species composition, stand density, canopy characteristics and topsoil properties.Results
In A. alba stands, seedling density was positively associated with the proximity of adult trees. In mixed stands of A. alba and P. abies, adult trees of both species exerted a positive effect on A. alba regeneration, but the P. abies neighbourhood influenced regeneration occurrence more strongly than the A. abies neighbourhood. In mixtures with F. sylvatica, however, the effect of local stand density and local species composition was not evidenced at all.Conclusion
Although at the stand level, P. abies and F. sylvatica exert a positive effect on A. alba regeneration, on the microsite scale, their influences differ. In stands with a dominance of A. alba, the hampered seedling establishment in gaps may be considered an inhibitive effect that facilitates the emergence of other species.55.
Wybraniec S Stalica P Spórna A Nemzer B Pietrzkowski Z Michałowski T 《Journal of agricultural and food chemistry》2011,59(22):12163-12170
The antioxidative mechanism of action of betalains is of significant interest because these pigments are recently emerging as highly bio-active natural compounds with potential benefits to human health. Betanidin, the basic betacyanin, comprises the 5,6-dihydroxyl moiety, which results in its high antioxidant activity. Oxidation of betanidin by voltammetric techniques and chro matographic identification of the oxidation products with spectrophotometric and mass spectrometric detection (LC-DAD-MS/MS) were performed. Two main oxidation peaks for betanidin are observable at pH 3-5. These peaks become merged at higher pH, suggesting a different mechanism of oxidation at higher and lower pH values. The low oxidation potential of betanidin confirms its very strong reduction properties. The presence of two prominent oxidized products, 2-decarboxy-2,3-dehydrobetanidin and 2,17-bidecarboxy-2,3-dehydrobetanidin, indicates their generation through two reaction routes with two different quinonoid intermediates: dopachrome derivative and quinone methide. Both lead to the decarboxylative dehydrogenation of betanidin. Subsequent oxidation and rearrangement of the conjugated chromophoric system results in formation of 14,15-dehydrogenated derivatives. 相似文献
56.
Blood samples were taken from 12 goats during the periparturient period (4 and 1 weeks before and 2, 10 and 30 days after delivery), and from 10 nonpregnant goats. The following variables were determined: total lipids (TL), triacylglycerol (TG), total cholesterol (TCH) and high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol fractions. One week before delivery TL (2.32 ± 0.12 g/l, P ≤ 0.05), TG (0.32 ± 0.16 mmol/l, P ≤ 0.001) and TCH concentrations (1.65 ± 0.42 mmol/l, P ≤ 0.05) were significantly increased as compared to non-pregnant goats (2.08 ± 0.28 g/l, 0.15 ± 0.05 mmol/l, 1.38 ± 0.19 mmol/l, respectively). After delivery, the concentrations of TL, TG, TCH and HDL decreased significantly. The lowest TG concentration was observed 2 days after delivery (0.18 ± 0.02 mmol/l), while TL (1.73 ± 0.21 g/l), TCH (0.95 ± 0.21 mmol/l) and HDL (0.74 ± 0.16 mmol/l) reached the lowest level 10 days after delivery. Two days after delivery a significant increase of LDL concentration was observed (0.38 ± 0.04 mmol/l); however, ten days after delivery a threefold decrease was shown in the LDL concentration (0.12 ± 0.04 mmol/l). A month after delivery all the variables studied reached levels similar to those measured in non-pregnant goats. 相似文献
57.
Gołkowski F Buziak-Bereza M Trofimiuk M Bałdys-Waligórska A Szybiński Z Huszno B 《Public health nutrition》2007,10(8):799-802
OBJECTIVE: To assess the prevalence of hyperthyroidism just after implementation of iodine prophylaxis among adults from an area with iodine deficiency. STUDY DESIGN AND SUBJECTS: A total of 1648 adults (age 16 years and older) were sampled from an area of southern Poland during two nationwide epidemiological surveys. Of these, 1424 adults with negative medical history for thyroid disorders qualified for final analysis. The authors compared thyroid dysfunction in participants prior to (1989-1990) and after implementation of iodine prophylaxis (1997-1999). SETTING: The southern part of Poland. RESULTS: We found an increase in the serum concentration of anti-thyroid microsomal antibodies from 4.9% in the years 1989-1990 to 12.1% after introduction of iodised household salt (P < 0.0001). The prevalence of hyperthyroidism (defined as thyroid-stimulating hormone < 0.4 microU ml- 1) significantly increased in the equivalent period from 4.8 to 6.5% (P = 0.009). CONCLUSIONS: We concluded that a sudden rise in iodine intake after implementation of iodine prophylaxis among adults from the area with iodine deficiency may lead to an increase in thyroid autoimmunity and prevalence of hyperthyroidism. Those possible early side-effects appear to be only temporary and are acceptable when compared with the evident benefits of adequate iodine intake. 相似文献
58.
Pérez C Muckle MT Zaleski DP Seifert NA Temelso B Shields GC Kisiel Z Pate BH 《Science (New York, N.Y.)》2012,336(6083):897-901
Theory predicts the water hexamer to be the smallest water cluster with a three-dimensional hydrogen-bonding network as its minimum energy structure. There are several possible low-energy isomers, and calculations with different methods and basis sets assign them different relative stabilities. Previous experimental work has provided evidence for the cage, book, and cyclic isomers, but no experiment has identified multiple coexisting structures. Here, we report that broadband rotational spectroscopy in a pulsed supersonic expansion unambiguously identifies all three isomers; we determined their oxygen framework structures by means of oxygen-18-substituted water (H(2)(18)O). Relative isomer populations at different expansion conditions establish that the cage isomer is the minimum energy structure. Rotational spectra consistent with predicted heptamer and nonamer structures have also been identified. 相似文献
59.
The aim of this research was to evaluate the amount of woody debris (m3/ha) on the forest floor and the associated wood-colonizing fungi. The study was performed in the Taborz region, known for its Scots pine provenance experiments, against the background of a recently launched Polish legislation to protect the biodiversity on the forest floor in managed (harvested) stands. We investigated a managed stand (136-years-old) and the reserve stand ‘Sosna Taborska’(261-years-old). In the reserve stand, the mean volume of woody debris was six times higher than in the managed forests, i.e. 65 versus 11 m3/ha. In addition, in the reserve stand, the number of fungi taxa colonizing the dead wood was larger than in the managed stands, with a higher number of fruitbodies. Total fungal richness was higher in the reserve than in the managed stand, i.e. 28 versus 12 species. The dominant taxa at both sites were Fomitopsis pinicola and Fomes The aim of this research was to evaluate the amount of woody debris (m^3/ha) on the forest floor and the associated wood-colonizing fungi. The study was performed in the Taborz region, known for its Scots pine provenance experiments, against the background of a recently launched Polish legislation to protect the biodiversity on the forest floor in managed (harvested) stands. We investigated a managed stand (136-years-old) and the reserve stand ‘Sosna Taborska’(261-years-old). In the reserve stand, the mean volume of woody debris was six times higher than in the managed forests, i.e. 65 versus 11 m^3/ha. In addition, in the reserve stand, the number of fungi taxa colonizing the dead wood was larger than in the managed stands, with a higher number of fruitbodies. Total fungal richness was higher in the reserve than in the managed stand, i.e. 28 versus 12 species. The dominant taxa at both sites were Fomitopsis pinicola and Fomes fomentarius, although some taxa were only found in the reserve (e.g., Stereum hirsutum). The volume of woody debris as well as the diversity of fungi in the managed stand were lower than in the reserve, albeit greater than in other Scots pine stands in Poland. These results testify to the gains in biodiversity yielded by the management conservation management approach at the reserve stand. 相似文献
60.
Ewa Pociecha Agnieszka Paek Franciszek Janowiak Zbigniew Zwierzykowski 《Physiological and Molecular Plant Pathology》2008,73(6):126-132
The metabolic changes in foliar abscisic acid, proline and phenolic concentration, and PAL activity induced during cold acclimation in androgenic forms of Festulolium contrasting in terms of their resistance to frost and Microdochium nivale were studied. The frost-resistant and snow mould-resistant (cross-tolerant) genotype (561) was characterized by a higher ABA amount and higher PAL activity compared to those of the frost and snow mould-susceptible genotype (621) during cold acclimation. The obtained results suggest that both these parameters are involved in a cross-tolerance mechanism relating to frost and snow mould resistance. 相似文献