National Repository of Grey Literature 9 records found  Search took 0.00 seconds. 
Involvement of AtKT/HAK/KUP high-affinity transporters in plant K+ and Cs+ uptake
Šustr, Marek ; Tylová, Edita (advisor) ; Maršík, Petr (referee)
Potassium is essential macroelement and large amount of potassium is taken up by plants, because it's the major osmotic of plant cell. Due to various potassium availability in different kinds of soil, plants have evolved transport system that can maintain sufficient K+ uptake between several orders of magnitude of potassium concentration. In Arabidopsis thaliana mechanism of K+ acquisition is well understood and it's known that AtHAK5 is mainly involved in K+ uptake in its very low concentrations. AtHAK5 belongs to KT/HAK/KUP family that consist 13 members in A. thaliana. There's known function for some members for example in auxin transport in root tip (TRH1) or in K+ efflux in stomatal closure (KUP6). In this thesis possible involvement of yet unstudied transporters KUP5, KUP7, KUP9 and KUP10 in K+ acquisition and homeostasis in A. thaliana was investigated. In vitro cultivation showed that kup9 mutant has very short lateral roots in K+ deficiency. On the other hand kup5 mutant showed significantly higher dry weight in K+ deficiency than Col-0. Kup9 phenotype was successfully replicated in subsequent cultivations and anatomy of lateral root apical meristems was investigated. Root tips of kup9 were differently organized in K+ deficiency and they showed signs of early termination of meristems. To...
Uptake and metabolism of 137Cs in plants
Šustr, Marek ; Tylová, Edita (advisor) ; Maršík, Petr (referee)
Plants are able to uptake radiocesium from soil, which is the potential route to enter the food chain. Cesium mobility in soil is determined by clay particles. Cesium can be reversibly ad- sorbed on their surface or can be fixed between layers. Mineral illit has the highest selectivity for cesium due to its frayed edges. Organic matter determines cesium mobility only in soil with organic matter content above 90 %. Cesium is more available for plants in this soil. Cesium uptake varies among species. Many plant species accumulating big amounts of cesium belong to family Chenopodiaceae. Cesium uptake is affected by other cations in soil solution. Potassium is the most effective one. Increasing of external potassium concentration from 50 μM to 250 μM decreased cesium uptake thirty-fold. Potassium affects cesium mobili- ty in soil and plant uptake. Due to chemical similarities of cesium and potassium some potassium transporters efficiently transport both cations. Potassium transporters are therefore considered the main entrance site in plant roots. Great contribution to cesium uptake is dedi- cated to high-affinity potassium transporter HAK5. Another great part of cesium uptake is mediated by non-selective cation channels. Plants can uptake up to 80 % of cesium applied on shoot surface. Cesium is highly...
In vitro determination of antimicrobial, antioxidative and antiphlogistic aktivity of quinones from seeds of Nigella sativa
Kokoška, L. ; Maršík, Petr ; Landa, Přemysl ; Tesařová, H. ; Svobodová, B. ; Halamová, K. ; Flesar, J. ; Přibylová, Marie
The in vitro anti-yeast, antioxidant, and anti-inf1ammatory activities ofblack cumin (Nigella sativa) seed quinones, namely dithymoquinone (DTQ), thymohydroquinone (THQ), and thymoquinone (TQ), were evaluated in frame of this work. The results showed that THQ and TQ possessed significant anti-yeast activity and affected the growth of aH strains tested at two pH levels with minimum inhibitory concentrations ranging from 8 to 128 !lg/ml. The best scavenging activity was produced by THQ, which showed a remarkable activity of 2.60 Trolox equivalents (TE) in a concentration range between 1.6 and 6.4 !lg/mL and lCso value of 2.4 !lg/mL in ORAC and DPPH assays, respectively. Contrastingly, TQ possessed only weak DPPH scavenging efficacy (ICso = 170 !lg/mL) but significant antioxidative action of 1.91 TE in ORAC assay. In anti-inf1ammatory assay, THQ and TQ possessed significant inhibitory activity against COX-l and -2 at the concentrations comparable with indomethacin. The data presented in this work suggest that THQ and TQ are biologically effective agents with potential for application in food or phalmaceutical industries.
Cytotoxicity of etxract from Vaccinium bracteatum
Landa, Přemysl ; Havlík, J. ; Bradshaw, T.D. ; Chu, J. ; Maršík, Petr ; Vaněk, Tomáš ; Lou, J.D.
Vaccinium bracteatum is a shrub originating from East Asia and is traditionally used for cancer treatment, according to some ethnobotanical indications. After successive extraction of dry berries with n-hexane, dichloromethane, methanol and water, the cytotoxic activity of extracts was assessed using the 3-( 4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) colourimetric assay. Methanolic extract showed mild cytotoxic properties against MCF-7, BCT-116 and MRC-5 cell lines with lCso ranging from 186 to 285 /lg/mL, while other extracts were not active (lC50>500 /lg/mL). The potency of methanolic extract only suggests a possible role of flavonoids.
Current options for use of metabolomics in plant production
Maršík, Petr ; Vaněk, Tomáš
Metabolomics like other so-called "omics" approaches is based on the characterization and treatment as far as possible in the given dataset biological system. Meaning of each "omics" techniques lies mainly in their mutual integration which leads to the so-called. Systems biology linking output at the level of gene expression, protein translation and file metabolites with genomic data. These relationships are summarized in Fig. 1. The primary goal of systems biology is to understand the biological processes to such an extent that it is possible to predict the function of biological systems from the level of genes through metabolism, physiological processes to growth and development.
Methodology for monitoring of air contamination in the vicinity of public roads by polycyclic aromatic hydrocarbons on the basis of their analysis on the surface of tree leaves
Maršík, Petr ; Kinderman, Pavel ; Vaněk, Tomáš
The methodology deals with the monitoring of polycyclic aromatic hydrocarbons (PAH) and applies a natural system of sedimentation of pollutants in local vegetation. According to the obtained results is possible to evaluate which of the used woody plants have higher capability to extract harmful substances such as PAH from the air and therefore should be preferred as a vegetation cover.
Phytoremediation of air - plans and reality
Vaněk, Tomáš ; Maršík, Petr ; Soudek, Petr
Results obtained so far indicate that selected plants can be effectively used to remove contaminants from the air, both horizontally and especially near sources of contamination, such as roads. When choosing plants, it is necessary to pay attention to their sorption capacities, as well as their ability to survive in contaminated sites, which are also exposed to other stresses such as lack of moisture and salinity.

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1 Maršík, P.
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