88 research outputs found

    Word of the Rector of the Nicolaus Copernicus University

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    Under the new law of the constitution for science, the veterinary science discipline is recognized in the field of agriculture sciences. Herein Nicolaus Copernicus University (NCU), the highlight of this year was the introduction of a new graduate study program in veterinary medicine which started from October 1st 2018. Along with this new graduate study, I am now glad to introduce and launch an open access peered-reviewed journal ÔÇťTranslational Research in Veterinary ScienceÔÇŁ (TRVS) under NCU publishers. In the beginning phase, TRVS journal will publish two issues a year. In launching the TRVS, the aim was to produce a journal of scientific discipline which could be read both in Poland and abroad, and which would promote scientific activities within the scope of veterinary science

    The chemical characteristic and distribution of brassinosteroids in plants

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    Brassinosteroids represent a class of plant hormones with high-growth promoting activity. They are found at low levels in pollen, anthers, seeds, leaves, stems, roots, flowers, grain, and young vegetative tissues throughout the plant kingdom. Brassinosteroids are a family of about 60 phytosteroids. The article gives a comprehensive survey on the hitherto known brassinosteroids isolated from plants. The chemical characteristic of brassinosteroids is also presented

    Acetylcholinesterase activity in Lycopersicon esculentum and its phytochrome mutants

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    Using the radiometric method, the activity of acetylcholinesterase (AChE, E.C. 3.1.1.7) was studied in seedlings of wild type (WT) and of phytochrome mutants of tomato (Lycopersicon esculentum Mill.). The activity of this enzyme was inhibited by an excess of substrate and by two well-known inhibitors of animal AChE, eserine and neostigmine. The activity of AChE was found in all etiolated organs as well as in light-grown seedlings. Under both conditions, the highest level of the enzyme activity was detected in cotyledons and the lowest one in root tissue. The enzyme activity was phytochrome-controlled. In WT etiolated seedlings red (R) light decreased AChE activity, whereas far red (FR) light abolished the red light effect. Furthermore, in light-grownWTseedlings the level of the enzyme activity was about twice higher than in etiolated plants. However, in the aurea phytochrome mutant of tomato, deficient in biosynthesis of a phytochrome chromophore, light had no effect on theAChE activity. In case of hp, fri and tri mutant seedlings, R and FR affected theAChE activity in a different way. Based on our results, we suggest that the type I of phytochrome is involved in the regulation of AChE activity. The type II of this photoreceptor influences the rate of the AChE synthesis de novo

    Organogenic response of photomorphogenic mutants of tomato

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    The effect of white (WL) and red (RL) light on organogenesis in vitro was studied using explants isolated from seedlings of wild-type (WT) and two photo morphogenic mutants of tomato (Lycopersicon esculentum Mill.) - aurea (au) and high pigment (hp). Explants excised from hypocotyls and cotyledons of green and etiolated seedlings were cultured on shoot or root inducing media. It was observed that both continuous white (CWL) and red light (CRL) stimulate shoot formation on hypocotyl explants isolated from green seedlings ofWT and hp plants compared with control ones cultured in darkness. On the other hand, au mutant shows very low organogenetic response in spite of light conditions applied. Explants isolated from both green and etiolated seedlings were not able to form shoots when they were cultured in darkness. In contrast to green explants, etiolated ones formed roots in spite of being grown on a shoot inducing medium. Root regeneration from etiolated explants was stimulated by short, 5-min-long daily pulses of RL. This effect was reversed by subsequent far-red light (FRL) irradiation. Stimulation of shoot regeneration from etiolated explants was found when 2-h-long daily irradiation with WL or RL was applied. The highest and the lowest shoot regeneration response was obtained from hp and au explants, respectively, with an intermediate response from WT. Under the same growth conditions shoot formation was accompanied by root formation, which also occurred in a light dependent manner. The highest number of roots regenerated from au-derived explants. The results that we have obtained may suggest that shoot formation is strongly dependent on the light sensitivity of plants and light conditions applied. It also seems that the pattern of organ (shoot and root) development in tomato is affected by the etiolated/deetiolated phenotype of explant. Therefore, w

    The effect of light on the level of acetylcholine in seedlings of the wild-type and phytochrome mutants of tomato (Lycopersicon esculentum Mill.)

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    Applying the method of pyrolysis coupled with gas chromatography (PYR-GC) the content of endogenous acetylcholine (ACh) was investigated in the extracts obtained from tomato (Lycopersicon esculentum Mill.). Seven-day-old seedlings of wild type (WT) and phytochrome mutants au (aurea), hp (high pigment), fri (far-red light insensitive) and tri (temporarily red light insensitive) were studied. In the analyzed material the presence of choline and acetylcholine was discovered. The highest content of ACh (381 mmole/g of fresh weight) was found in tomato cotyledons, whereas the lowest amount (162 nmole/g of fresh weight) in roots. The level of ACh in the plants grown under the continuous light was higher than in etiolated ones. However, no considerable differences in the concentrations of ACh in au and tri seedlings grown under the continuous light and in darkness were observed. The irradiation of etiolated seedlings of wild type with red light was accompanied by the increase of endogenous level of ACh. The pulse of far-red light applied directly after red light reversed this stimulating effect. A similar effect of both light wavelengths on the content of ACh was also found in the case of the tri mutant. On the other hand, in the case offi-i mutant, pulse of red light caused the drop in the content of ACh, whereas far-red applied after red light caused visible increase in the level of the investigated substance. In tissues of au mutant no effect of red and far-red lights on the concentration of ACh was established

    Acetylcholine in plants: presence, metabolism and mechanism of action

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    Acetylcholine (ACh) has been detected in representatives of many taxonomic groups throughout the plant kingdom. The site of its synthesis in plants is probably young leaves. In some plant species choline acetyltransferase (CHAT) activity has been found. This enzyme showing properties similar to animal CHAT, probably participates in ACh synthesis from its precursors, choline and acetyl-Coenzyme A. Acetylcholinesterase (ACHE) activity has also been found in many plant tissues. This enzyme decomposes ACh and exhibits properties similar to animal ACHE. The presence of both ChAT and AChE in plant tissues suggests that ACh undergoes similar metabolism in plants as it does in animals. Exogenous ACh affects phytochrome- controlled plant growth and development. Mimicking red light (R), ACh stimulates adhesion of root tips to a glass surface and influences leaf movement and membrane permeability to ions. It also affects seed germination and plant growth. Moreover, ACh can modify some enzyme activity and the course of some metabolic processes in plants. Acetylcholine in the presence of calcium ions (Ca:+), like R stimulates swelling of protoplast isolated from etiolated wheat leaves. It is proposed that the primary mechanism of action of ACh in plant cells is via the regulation of membrane permeability to protons (H+), potassium ions (K+), sodium ions (Na +) and Ca :+ .Acetylcholin (ACh) wurde in Vertretern vieler taxonomischer Gruppen des Pflanzreiches gefunden. Es wird wahrscheinlich inden jungen Bltittern synthetisiert. In einigen Pflanzen hat man daneben Cholin-Acetyltransferase (ChAT)-Activit~t nachweisen k6nnen; dieses Enzym ziegt tihnliche Eigenschaften wie tierische ChAT und ist offenbar an der ACh-Synthese aus sienen Vorstufen Cholin und Acetyl-Coenzym A beteiligt. Acetylcholineesterase (AChE)-Activit~t wurde ebenfalls in vielen Pflanzengeweben gefunden; dieses Enzym spaltet ACh und ziegt ~ihnliche Eigenschaften wie tierische ACHE. Die Anwesenheit yon ChAT und AChE in pflanzlichem Gewebe ltil3t vermuten, dal3 ACh in Pflanzen einem ~ihnlichen Metabolismus unterliegt wie im tierischen System. ~,hnlich wie Rotlicht stimuliert ACh die Anheftung von Wurzelspitzen an Glasoberfltichen und beeinflul3t Blattbewegung und Membranpermeabilit~t far Ionen; dariiber hinaus beeinflul3t es Samenkeimung und pflanzliches Wachstum. Des weiteren kann ACh Enzym-Aktivit~ten modifizieren und dadurch den Ablauf einiher metabolischer Prozesse in Pflanzen. SchlieBlich stimuliert ACh in Gegenwart von Calcium-Ionen (Ca2┬ž ~ahnlich wie Rotlicht, das Schwellen von Protoplasten etiolierter Weizenbl~itter. Es wird vermutet, dal3 die Primiirwirkung von ACh in Pflanzenzellen durch Regulation der Membranpermeabilit~it far Protonen (H┬ž Kaliumionen (K┬ž Natriumionen (Na ┬ž und Ca 2┬ž erfolgt

    Plant signalling peptides

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    Biochemical and genetic studies have identified peptides that play crucial roles in plant growth and development, including defence mechanisms in response to wounding by pests, the control of cell division and expansion, and pollen self-incompatibility. The first two signalling peptides to be described in plants were tomato systemin and phytosulfokine (PSK). There is also biochemical evidence that natriuretic peptide-like molecules, immunologically-relatedt o those found in animals,m ay exist in plants. Another example of signalling peptide is ENOD40, a product of a gene, which became active early in the root nodulation process following Rhizobium infection of legumes. Other predicted bioactive peptides or oligopeptides have been identified by means of genetic, rather then biochemical methods. The Arabidopsis CLAVATA3 protein is required for the correct organization of the shoot apical meristem and the pollen S determinant S-locus cysteine-rich protein (SCR also called S-locus protein 11, SP11). The plant signalling peptides discovered so far are involved in various processes and play an important role in communication between cells or organs, respectively. This review will focus on these peptides and their role in intercellular signalling

    Reactive oxygen species localization in roots of Arabidopsis thaliana seedlings grown under phosphate deficiency

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    Arabidopsis plants responding to phosphorus (P) deficiency increase lateral root formation and reduce primary root elongation. In addition the number and length of root hairs increases in response to P deficiency. Here we studied the patterns of radical oxygen species (ROS) in the roots of Arabidopsis seedlings cultured on media supplemented with high or low P concentration. We found that P availability affected ROS distribution in the apical part of roots. If plants were grown on high P medium, ROS were located in the root elongation zone and quiescent centre. At low P ROS were absent in the elongation zone, however, their synthesis was detected in the primary root meristem. The proximal part of roots was characterized by ROS production in the lateral root primordia and in elongation zones of young lateral roots irrespective of P concentration in the medium. On the other hand, plants grown at high or low P differed in the pattern of ROS distribution in older lateral roots. At high P, the elongation zone was the primary site of ROS production. At low P, ROS were not detected in the elongation zone. However, they were present in the proximal part of the lateral root meristem. These results suggest that P deficiency affects ROS distribution in distal parts of Arabidopsis roots. Under P-sufficiency ROS maximum was observed in the elongation zone, under low P, ROS were not synthesized in this segment of the root, however, they were detected in the apical root meristem

    The association between 3020INSC mutation in NOD2 gene and arterial stiffness in hypertensives.

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    The innate immune system elicits an inflammatory process which is believed to be involved in the development of vascular damage in hypertension. The NOD2 gene (CARD15) is involved in the control of the innate immune system. The aim of this study was to assess the occurrence of the 3020insC mutation in the NOD2 gene in relation to vascular damage in hypertensives

    The role of the plasma-membrane Ca2+-ATPase in ca2+ homeostasis in Sinapis alba root hairs

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    The regulation of cytosolic Ca2+ has been investigated in growing root-hair cells of Sinapis alba L. with special emphasis on the role of the plasmamembrane Ca2+-ATPase. For this purpose, erythrosin B was used to inhibit the Ca2+-ATPase, and the Ca2+ ionophore A23187 was applied to manipulate cytosolic free [Ca2+] which was then measured with Ca2+-selective microelectrodes. (i) At 0.01 M, A23187 had no effect on the membrane potential but enhanced the Ca2+ permeability of the plasma membrane. Higher concentrations of this ionophore strongly depolarized the cells, also in the presence of cyanide. (ii) Unexpectedly, A23187 first caused a decrease in cytosolic Ca2+ by 0.2 to 0.3 pCa units and a cytosolic acidification by about 0.5 pH units, (iii) The depletion of cytosolic free Ca2+ spontaneously reversed and became an increase, a process which strongly depended on the external Ca2+ concentration, (iv) Upon removal of A23187, the cytosolic free [Ca2+] returned to its steady-state level, a process which was inhibited by erythrosin B. We suggest that the first reaction to the intruding Ca2+ is an activation of Ca2+ transporters (e.g. ATPases at the endoplasmic reticulum and the plasma membrane) which rapidly remove Ca2+ from the cytosol. The two observations that after the addition of A23187, (i) Ca2+ gradients as steep as-600 mV could be maintained and (ii) the cytosolic pH rapidly and immediately decreased without recovery indicate that the Ca2+-exporting plasma-membrane ATPase is physiologically connected to the electrochemical pH gradient, and probably works as an nH+/Ca2+-ATPase. Based on the finding that the Ca2+-ATPase inhibitor erythrosin B had no effect on cytosolic Ca2+, but caused a strong Ca2+ increase after the addion of A23187 we conclude that these cells, at least in the short term, have enough metabolic energy to balance the loss in transport activity caused by inhibition of the primary Ca2+-pump. We further conclude that this ATPase is a major Ca2+ regulator in stress situations where the cytosolic Ca2+ has been shifted from its steady-state level, as may be the case during processes of signal transduction
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