Anna Kołton

Strategy of Cr detoxification by Callitriche cophocarpa

AbstractThe present work focused on the qualitative and quantitative analysis of Cr detoxification strategy of aquatic cosmopolitan plant Callitriche cophocarpa. This plant species has just been described in the context of its unusual accumulation potential of Cr. The emphasis of the work was placed on the redox reaction Cr(VI)→Cr(III) which is considered to be remediation mechanism of highly reactive and mobile Cr(VI) ions. Plants were immersed for 5 days in 1 mM of Cr(VI) (potassium dichromate) or 1 mM of Cr(III) (chromium sulphate) solutions in semi-natural conditions. Cr was effectively removed from the solution up to the extent of ca.58% or 35% of the starting amount, in the case of Cr(III) and Cr(VI), respectively. No plant-induced Cr(VI) reduction accompanying Cr accumulation was observed in Cr(VI) solutions except from the apparent one, noticed at the fourth day of incubation. On the contrary to these results, according to the method of electron paramagnetic resonance spectroscopy (L-band EPR), biphasic signal of Cr(V) attending Cr(VI) to Cr(III) reduction was detected inside the plant tissue every day of investigations. Our results show that phytoextraction but not phytostabilization is the main strategy of Cr detoxification by C. cophocarpa in aquatic systems.

The effect of LED lighting on photosynthetic parameters and weight of lamb's lettuce (Valerianella locusta).

ABSTRACT The experiment was carried out in the winter and autumn of 2011 using lamb’s lettuce (Valerianella locusta Laterr. Em Betce) as a test plant under greenhouse growing conditions. The aim of the study was to evaluate the effect of a prolonged day with modern SSL LED (Solid State Lighting Light Emitting Diodes) technology on photosynthetic parameters and plant yield. Two kinds of LED lamps with different spectral properties were used. The first emitted a white light and the second a mixture of red and blue light. Measurements of chlorophyll fluorescence and gas exchange were taken in natural and artificial light. Control plants were not treated with additional lighting. During the day with natural light in March (winter growing), photosynthesis intensity, stomatal conductance and transpiration of lamb’s lettuce leaves were higher than in November (autumn growing). In the evening hours of March and November, during artificial plant lighting, similar photosynthesis intensity was observed. This intensity was significantly higher than in the afternoon hours (by natural light) in the autumn. The highest content of chlorophyll a, b and carotenoids was found in the treatment with red+blue LEDs in winter growing. Supplemental lighting with red+blue LED light stimulated the high efficiency of the photosynthetic apparatus, which was manifested by the highest Performance Index (PI). The highest weight of the rosettes was noted in the autumn growing period in plants that were under the influence of the red+blue supplemental lighting followed by the white LED. This could be the result of a significant stimulation of photosynthesis during supplemental lighting with the LED lamps during this period.

Effect of Maturity Stage and Short-Term Storage on the Biological Quality of Sweet Pepper Fruits

Effect of Maturity Stage and Short-Term Storage on the Biological Quality of Sweet Pepper Fruits Sweet pepper plants of Spartacus cultivar were grown in plastic tunnel on rockwool using the fertigation technique. The three year experiment was carried out in 2006-2008. Fruits were harvested every year in three maturity stages: green, turning and red. The contents of ascorbic acid, phenols, soluble sugars, nitrate and ammonium ions, total nitrogen, free amino acids and dry matter were determined in freshly harvested fruits as well as after short-term (two weeks) storage. Red pepper fruits accumulated significantly more ascorbic acid, soluble sugars and phenols in comparison with the green and turning ones. The level of nitrate ions was highest in the green fruits and decreased during their ripening while the ammonium ion concentration increased. The lowest content of amino acids was observed in green fruits. Two week storage at 5-8°C, followed by two days at room temperature caused the reduction of nitrate ions in green and red fruits. Ammonium ion content as well as phenol and soluble sugar level increased in stored fruits, irrespectively of their maturity stage. Ascorbic acid content increased in the stored turning and red pepper fruits as related to its initial concentration. Dry matter content did not change after storage. Biological quality of harvested pepper fruits depended of their maturity stage, however, their response to short-term storage was similar. Wpływ Fazy Dojrzałości Oraz Krótkotrwałego Przechowywania na Jakość Biologiczną Owoców Papryki Słodkiej Paprykę słodką ‘Spartacus’ uprawiano w tunelu wysokim na wełnie mineralnej z wykorzystaniem systemu fertygacyjnego. Doświadczenie przeprowadzono w latach 2006-2008. Owoce papryki zbierano w trzech fazach dojrzałości: zielone, przebarwiające się oraz czerwone. W materiale roślinnym oznaczono zawartość kwasu askorbinowego, sumy fenoli, cukrów rozpuszczalnych, azotanów i jonów amonowych, a także azotu całkowitego, wolnych aminokwasów i suchej masy. Analizy przeprowadzono tuż po zbiorze owoców, a także po ich krótkotrwałym przechowywaniu. W czerwonych owocach papryki oznaczono istotnie więcej kwasu askorbinowego, cukrów rozpuszczalnych i fenoli niż w owocach zielonych czy przebarwiających się. Zawartość azotanów była najwyższa w owocach zielonych i obniżała się w trakcie dojrzewania, podczas gdy zawartość jonów amonowych rosła w trakcie wybarwiania się owoców. Najniższym poziomem wolnych aminokwasów charakteryzowały się owoce zielone. Owoce papryki przechowywano dwa tygodnie w temperaturze 5-8°C, a następnie dwa dni w temperaturze pokojowej. Przechowywanie wpłynęło na obniżenie zawartości jonów azotanowych w zielonych i czerwonych owocach papryki. W trakcie przechowywania zwiększała się zawartość jonów amonowych, fenoli i cukrów rozpuszczalnych niezależnie od stopnia dojrzałości. W przypadku owoców przebarwiających się i czerwonych obserwowano wzrost zawartości kwasu askorbinowego w trakcie przechowywania. Nie notowano natomiast zmian w zawartości suchej masy w owocach papryki. Wartość biologiczna papryki była zależna od fazy dojrzałości owoców w momencie zbioru, podczas gdy w trakcie przechowywania notowano podobne zmiany składników niezależnie od fazy dojrzałości.

The effect of various light conditions and different nitrogen forms on nitrogen metabolism in pepper fruits

Abstract The ‘Spartacus’ F1 sweet pepper was grown in a plastic tunnel on rockwool during 2006-2008. A fertigation technique was used for water and fertiliser application. The tunnel was divided into two parts covered with different plastic films. The first part of the tunnel was covered with a film that transmitted less light than the film covering the second part. In both parts of the tunnel, the plants were divided into two groups. One group of plants was fertilised with just nitrate nitrogen (100% N-NO3) and the other one with three forms of nitrogen (N-NO3:N-NH4:N-NH2 in a ratio of 50:13:37). Fruits were harvested mature green and red. Concentrations of nitrate and ammonium ions as well as total nitrogen and free amino acids were analysed in the plant material. Nitrate and nitrite reductase activities were also investigated, and dry matter content and soluble sugars were also determined. Higher light intensity increased nitrate concentration in red pepper fruits but decreased ammonium ion content. These tendencies were not as obvious in green fruits. In most cases, red fruits fertilised with three nitrogen forms accumulated more nitrates than those fertilised with N-NO3. This observation was similar in the case of green fruits. In most cases, pepper fruits accumulated more ammonium ions in the case of N-NO3 fertilisation than when three forms of nitrogen were applied, but the differences were not always statistically significant. Higher nitrate reductase activity was observed in the case of better light conditions as well as mixed nitrogen fertilisation in red pepper fruits. No differences were observed in the case of nitrite reductase activity between fruits harvested from various treatments in red and also green fruits, with some exceptions. The green fruits of pepper had higher nitrate reductase activity than the red ones. It can be summarised that various light conditions influenced the nitrogen metabolism of pepper fruits as well as the different nitrogen forms applied with fertilisers.

Physiological responses of Betula pendula Roth growing in polluted areas

Plant functioning is affected by drought, extreme temperatures, heavy metal pollution and other unfavorable environmental conditions. High intensity of stress factors can be lethal to sensitive organisms or significantly decrease their condition. Intensification of stress factors is observed especially in urban and industrial areas. During the vegetative season plants purify the air and soil, decrease air temperature, increase humidity and have others psychosociological advantages. It is especially important to monitor growth of plants in areas with high anthropopression. In presented study condition of silver birch ( Betula pendula Roth) growing in different stressful environments was investigated. During the research soil parameters such as pH, EC and heavy metals content were observed. Chlorophyll a fluorescence, photosynthetic pigment content, phenolic compounds concentration, ability to scavenging DPPH free radical, activity of anti-oxidative enzymes (superoxide dismutase-SOD, peroxidase-POD, catalase-CAT) were examined in the leaves to study plant response to stress factors. Investigated trees showed two types of antioxidative defense systems: with high activity of low molecular weight antioxidants (phenolics) or with high enzymatic antioxidant activity. The most stressed trees showed highest concentration of low molecular weight antioxidants (phenolics).

THE STORAGE ABILITY OF LAMB'S LETTUCE CULTIVATED IN THE GREENHOUSE UNDER LED OR HPS LAMPS

Abstract Leafy vegetables are the source of many valuable components like vitamins, minerals and phenolic compounds as antioxidants. Chlorophyll derivatives have antioxidant and anticarcinogenic activity, or may even act as signalling molecules in organisms. However, during the storage of the leafy vegetables in the cold and darkness, numerous biochemical changes usually occurs, demonstrated as the breakdown of chlorophyll. Storage ability of plants depends to some extent on the conditions under which plants grew. Lamb’s lettuce plants were grown in the greenhouse in different light regimes - emitted with sodium (HPS-control) and LED lamps (100% red, 90% red + 10% blue, 70% red + 30% blue and 50% red + 50% blue light). The intensity of radiation at the height of the leaves of the plants was the same in every treatment. After harvesting, the plants were stored at the temperature of 5 °C and high humidity in plastic bags. The analyses of the material were done four times: after harvest and three times during storage at weekly intervals. Fresh weight lost, dry matter, phenolics and chlorophyll content were analysed. Additionally, the fluorescence of chlorophyll a was carried out. Changes in plant fresh weight and dry matter content during storage did not depend on the lighting used during cultivation. After 3 weeks of storage, higher value of indicator of the vitality of PSII (PIABS - Performance Index) was noticed in leaves treated with higher red light intensity during cultivation (100%, 90% and 70% red). LED lamps, which emitted 100% and 90% red light, enhanced concentration of total phenolics in lamb’s lettuce leaves. Light of HPS lamps decreased radical scavenging activity in leaves. Quality and usefulness of plants produced under LED lamps was just as good as those grown under HPS lamps.

Content and health risk assessment of selected elements in the Yerba mate (Ilex paraguariensis, St. hillaire)

ABSTRACT Element contents and radical scavenging activity in commercial Yerba mate tea blends from Paraguay and Argentina were determined. The potential health risk for the consumers was also calculated. Element contents in Yerba mate was arranged as follows: K > Ca > Mg > Mn > Fe > Zn > Na > Cu > Ni > Cr > Pb > Cd (leaves and stalks) and K > Mg > Mn > Ca > Zn > Na > Fe > Cu > Ni > Cr > Pb > Cd (infusion). In total 73% of K, 69% of Mn, 15% of Ni and Cu, 9% of Cr, 8% of Zn, 7% of Mg, 6% of Pb, 3% of Na, 2% of Cd, 0.34% of Ca, and 0.13% of Fe were extracted from leaves and stalks to the brew. Yerba mate tea was characterized by very high antioxidant activity. Argentinean Yerba mate had slightly higher antioxidant activity than Paraguayan. The combined non-carcinogenic effect (HI values) for each infusion and for all three infusion were below 1, which indicated that daily consumption of Yerba mate tea infusions did not cause essential non-carcinogenic health risk. The daily consumption of Yerba mate infusions provided necessary elements in the amounts significantly below 1% of the Recommended Dietary Allowance (RDA) daily intake. The exception was amount of Mn in I infusion from the despalada kind of Yerba mate, which was equal to 1.43% of RDA for men and 1.82% of RDA for women.

Methylation of protein phosphatase 2A – influence of regulators and environmental stress factors

Protein phosphatase 2A catalytic subunit (PP2A-C) has a terminal leucine subjected to methylation, a regulatory mechanism conserved from yeast to mammals and plants. Two enzymes, LCMT1 and PME1, methylate and demethylate PP2A-C, respectively. The physiological importance of these posttranslational modifications is still enigmatic. We investigated these processes in Arabidopsis thaliana by mutant phenotyping, by global expression analysis, and by monitoring methylation status of PP2A-C under different environmental conditions. The lcmt1 mutant, possessing essentially only unmethylated PP2A-C, had less dense rosettes, and earlier flowering than wild type (WT). The pme1 mutant, with 30% reduction in unmethylated PP2A-C, was phenotypically comparable with WT. Approximately 200 overlapping genes were twofold upregulated, and 200 overlapping genes were twofold downregulated in both lcmt1 and pme1 relative to WT. Differences between the 2 mutants were also striking; 97 genes were twofold upregulated in pme1 compared with lcmt1, indicating that PME1 acts as a negative regulator for these genes. Analysis of enriched GO terms revealed categories of both abiotic and biotic stress genes. Furthermore, methylation status of PP2A-C was influenced by environmental stress, especially by hypoxia and salt stress, which led to increased levels of unmethylated PP2A-C, and highlights the importance of PP2A-C methylation/demethylation in environmental responses.

Some physiological changes in autumn leaves of Parthenocissus inserta growing in urban conditions

Introduction Autumnal leaf color change is a decorative feature, but the intensity of colors in this period is not always the same. Physiological processes that determine the colors of autumn leaves are affected by many factors, including weather conditions (Feild et al., 2001; Archetti et al., 2009). Red color of the leaves is caused by anthocyanins, which synthesis is stimulated by night temperature falls (up to a few degrees above zero) followed by sunny weather. During autumn low temperature accelerates the chlorophyll breakdown, revealing the yellow-orange carotenoids. An important factor in the selection of species is a similar color change regardless of the weather fluctuations. One of these species is Parthenocissus inserta – Thicket Creeper – fast growing, expansive rambler, climbing by tendrils, with green young shoots, reaching up to 20 m in height (Seneta and Dolatowski, 2008). In addition to the strong spring-summer shoot growth, and quick cover of different areas, the main decorative advantage of P. inserta is intense red leaf color in the autumn. It is successfully planted in urban areas, enduring the pollution of soil and air and water shortages (Borowski, 1996). The compact construction of the city center, including transport routes are the warmest areas of Cracow, while the coldest – water reservoirs surface, large forests and parks, including “Las Borkowski” area (Matuszko, 2007). The aim of the study was to examine selected physiological changes (pigment content, the state of the cytoplasmic membrane), occurring especially in the autumn leaves of Parthenocissu sinserta, growing in three different positions in Cracow. The aim was also to determine how the tested parameters are affected by the location of the plant leaves in the crown.

Antiradical Properties of Selected Alium Cultivars

Antioxidant capacity of edible parts and tunic of nine selected onion cultivars of yellow, red and white color was estimated in freshly harvested bulbs and after long-term winter storage. Phenolic substances such as total, phenylpropanoids, flavonols and anthocyanins were detected by spectrophotometric and HPLC methods. Radical scavenging activity was measured in tissue extracts and expressed as the percentage of DPPH neutralization. Great variability of phenolics was observed in the onion flesh as well as in the tunic, the level of them determined in the skin was considerably higher in comparison with the edible parts. Antiradical activity of the flesh was poor, however, in the tunic exceeded 60% and was correlated with content of total phenols. Five month storage did not affect either phenolic substances or RSA in onion tunic while in flesh the significant decrease of antiradical activity was noted.