The composition of defensive secretion produced by metathoracic scent glands was analysed in males and females of the milkweed bug Lygaeus equestris (Heteroptera) using gas chromatography with mass spectrometric detection (GC-MS). The bugs were raised either on cardenolide-containing Adonis vernalis or on control sunflower seeds in order to determine whether the possibility to sequester cardenolides from their host plants would affect the composition of defensive scent-gland secretion. Profiles of the composition of defensive secretions of males and females raised on sunflower were closely similar, with predominant presence of (E)-2-octenal, (E)-2-octen-1-ol, decanal and 3-octen-1-ol acetate. The secretion of bugs raised on A. vernalis was more sexually dimorphic, and some chemicals e.g. (E,E)-2,4-hexadienyl acetate and 2-phenylethyl acetate were dominant in males, but absent in females. Compared to bugs from sunflower, the scent-gland secretion of bugs raised on A. vernalis was characterized by lower overall intensity of the peaks obtained for detected chemicals and by absence of some chemicals that have supposedly antipredatory function ((E)-2-hexenal, (E)-4-oxo-hex-2-enal, 2,4-octadienal). The results suggest that there might be a trade-off between the sequestration of defensive chemicals from host plants and their synthesis in metathoracic scent-glands.

• MeSH
• acetáty analýza   MeSH
• aldehydy analýza   MeSH
• chromatografie plynová MeSH
• čich MeSH
• fenethylalkohol analogy a deriváty   analýza   MeSH
• feromony analýza   MeSH
• Helianthus chemie   MeSH
• Heteroptera chemie   MeSH
• hlaváček chemie   MeSH
• obranné mechanismy proti býložravcům * MeSH
• pachové žlázy chemie   MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• pohlavní dimorfismus MeSH
• sexuální faktory MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Characterisation of geochemical transformations and processes in soils with special focus on the rhizosphere is crucial for assessing metal(loid) bioavailability to plants during in situ immobilisation and phytostabilisation. In this study, the effects of nano zero-valent iron (nZVI) were investigated in terms of the immobilisation of As, Zn, Pb and Cd in two soil types and their potential uptake by plants using rhizobox experiments. Such system allowed monitoring the behaviour of trace elements in rooted and bulk soil compartments separately. Sunflower (Helianthus annuus L.) and ryegrass (Lolium perenne L.) were tested for As-rich (15.9 g As kg-1) and Zn-rich (4.1 g Zn kg-1) soil samples, respectively. The application of nZVI effectively lowered the uptake of all target risk elements into plant tissues. Efficient immobilisation of As was determined in the As-soil without a significant difference between plant and bulk soil compartments. Similarly, a significant decrease was determined for CaCl2-available fractions of Zn, Pb and Cd in nZVI-treated Zn-soil. The behaviour of As corresponded to changes in Eh, while Zn and Cd showed to be mainly pH-dependent. However, despite the observed stabilisation effect of nZVI, high amounts of As and Zn still remained available for plants. Furthermore, the accumulation of the target risk elements in roots and the overall effect of nZVI transformations in the rhizosphere were verified and visualised by SEM/EDS. The following immobilising mechanisms were suggested: (i) sorption onto both existing and newly formed Fe (hydr)oxides, (ii) formation of secondary Fe-As phases, and (iii) sorption onto Mn (hydr)oxides.

• MeSH
• arsen analýza   chemie   MeSH
• biologická dostupnost MeSH
• Helianthus účinky léků   růst a vývoj   metabolismus   MeSH
• jílek účinky léků   růst a vývoj   metabolismus   MeSH
• kadmium analýza   chemie   MeSH
• kořeny rostlin chemie   MeSH
• látky znečišťující půdu analýza   chemie   MeSH
• olovo analýza   chemie   MeSH
• regenerace a remediace životního prostředí * MeSH
• rhizosféra * MeSH
• stopové prvky analýza   chemie   MeSH
• těžké kovy analýza   chemie   MeSH
• železo farmakologie   MeSH
• zinek analýza   chemie   MeSH
• znečištění životního prostředí prevence a kontrola   MeSH
• Publikační typ
• časopisecké články MeSH

Several efficient stabilizing amendments have been recently proposed for the remediation of metal(loid)-contaminated soils. However, information on their interactions with plants, which is a crucial factor in soil environments, are still scarce. An amorphous manganese oxide (AMO) synthesized from organic compounds and nano zerovalent iron (nZVI) have been previously tested as promising stabilizing agents usable both for the stabilization of metals and As. Experiments with rhizoboxes were performed in order to evaluate their influence on the mobility of metal(loid)s in the bulk soil and rhizosphere of sunflower (Helianthus annuus L.) together with their impact on metal uptake and biomass yield. Generally, AMO proved more efficient than nZVI in all stages of experiment. Furthermore, the AMO effectively reduced water- and 0.01 M CaCl2-extractable fractions of Cd, Pb and Zn. The decreased bioavailability of contaminating metal(loid)s resulted in significant increase of microbial activity in AMO-amended soil. Together with metal(loid) extractability, the AMO was also able to significantly reduce the uptake of metals and ameliorate plant growth, especially in the case of Zn, since this metal was taken up in excessive amounts from the control soil causing strong phytotoxicity and even death of young seedlings. On the other hand, AMO application lead to significant release of Mn that was readily taken up by plants. Resulting Mn concentrations in biomass exceeded toxicity thresholds while plants were showing emergent Mn phytotoxicity symptoms. We highlight the need of such complex studies involving plants and soil biota when evaluating the efficiency of stabilizing amendments in contaminated soils.

• MeSH
• Bacteria účinky léků   růst a vývoj   MeSH
• biomasa MeSH
• Helianthus * růst a vývoj   metabolismus   MeSH
• látky znečišťující půdu analýza   farmakokinetika   toxicita   MeSH
• oxidy chemická syntéza   farmakokinetika   farmakologie   MeSH
• půda MeSH
• regenerace a remediace životního prostředí metody   MeSH
• sloučeniny manganu chemická syntéza   farmakokinetika   farmakologie   MeSH
• těžké kovy analýza   farmakokinetika   toxicita   MeSH
• železo chemie   MeSH
• Publikační typ
• časopisecké články MeSH

The application of nanomaterials in commercially available products is increasing rapidly for agriculture, phytoremediation and biotechnology. Since plants suppose the first sink for the accumulation of nanoparticles from the environment, emerging studies have focused on the general consequences for plants and their effects on the biomass production. However, effects on the root surface, as well as blockage of nutrients and water uptake by the roots, may also occur. This experiment was designed to prove if the plant water relations can be affected by the adsorption of nanoparticles on the root surface, causing a consequent stress for the plants. With this goal, plants of Helianthus annuus were previously grown in a hydroponic culture, and at age of 55 days, their roots were exposed to three different concentrations of nanomaghemite (NM) in the hydroponic solution for 5 days: control without NM; 50 and 100 mg l(-1) NM. The main effect was related to the reduction of the root hydraulic conductivity (Lo) and the nutrients uptake. The concentrations of the macronutrients Ca, K, Mg and S in the shoot were reduced relative to the control plants, which resulted in lower contents of chlorophyll pigments. Although stress was not detected in the plants, after the analysis of stress markers like the accumulation of proline or ascorbate in the tissues, reduction of the root functionality by nanoparticles has been identified here, manifested as the effect of NM on Lo. The treatment with 50 mg l(-1) NM significantly reduced the Lo, by up to 57% of its control value, and it was reduced by up to 26% at 100 mg l(-1) NM. These results will be an important factor to take into account with regard to the applicability of NM for long-term use in crops, particularly during privative water conditions.

• MeSH
• biologický transport MeSH
• biomasa MeSH
• chlorofyl metabolismus   MeSH
• Helianthus účinky léků   růst a vývoj   metabolismus   MeSH
• kořeny rostlin účinky léků   růst a vývoj   metabolismus   MeSH
• nanočástice toxicita   MeSH
• prolin metabolismus   MeSH
• voda metabolismus   MeSH
• železité sloučeniny farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Downy mildews are the most speciose group of oomycetes and affect crops of great economic importance. So far, there is only a single deeply-sequenced downy mildew genome available, from Hyaloperonospora arabidopsidis. Further genomic resources for downy mildews are required to study their evolution, including pathogenicity effector proteins, such as RxLR effectors. Plasmopara halstedii is a devastating pathogen of sunflower and a potential pathosystem model to study downy mildews, as several Avr-genes and R-genes have been predicted and unlike Arabidopsis downy mildew, large quantities of almost contamination-free material can be obtained easily. RESULTS: Here a high-quality draft genome of Plasmopara halstedii is reported and analysed with respect to various aspects, including genome organisation, secondary metabolism, effector proteins and comparative genomics with other sequenced oomycetes. Interestingly, the present analyses revealed further variation of the RxLR motif, suggesting an important role of the conservation of the dEER-motif. Orthology analyses revealed the conservation of 28 RxLR-like core effectors among Phytophthora species. Only six putative RxLR-like effectors were shared by the two sequenced downy mildews, highlighting the fast and largely independent evolution of two of the three major downy mildew lineages. This is seemingly supported by phylogenomic results, in which downy mildews did not appear to be monophyletic. CONCLUSIONS: The genome resource will be useful for developing markers for monitoring the pathogen population and might provide the basis for new approaches to fight Phytophthora and downy mildew pathogens by targeting core pathogenicity effectors.

• MeSH
• biologická evoluce MeSH
• faktory virulence genetika   MeSH
• fosfolipidy metabolismus   MeSH
• fungální proteiny MeSH
• fylogeneze MeSH
• genom fungální * MeSH
• genomika metody   MeSH
• Helianthus mikrobiologie   MeSH
• heterozygot MeSH
• mikrosatelitní repetice MeSH
• oomycety klasifikace   genetika   metabolismus   MeSH
• Phytophthora genetika   MeSH
• promotorové oblasti (genetika) MeSH
• repetitivní sekvence nukleových kyselin MeSH
• sekundární metabolismus MeSH
• signální transdukce MeSH
• stanovení celkové genové exprese MeSH
• Publikační typ
• časopisecké články MeSH

The anticonvulsant drug carbamazepine is considered as an indicator of sewage water pollution: however, its uptake by plants and effect on metabolism have not been sufficiently documented, let alone its metabolite (10,11-epoxycarbamazepine). In a model system of sterile, hydroponically cultivated Zea mays (as C4 plant) and Helianthus annuus (as C3 plant), the uptake and effect of carbamazepine and 10,11-epoxycarbamazepine were studied in comparison with those of acetaminophen and ibuprofen. Ibuprofen and acetaminophen were effectively extracted from drug-supplemented media by both plants, while the uptake of more hydrophobic carbamazepine was much lower. On the other hand, the carbamazepine metabolite, 10,11-epoxycarbamazepine, was, unlike sunflower, willingly taken up by maize plants (after 96 h 88 % of the initial concentration) and effectively stored in maize tissues. In addition, the effect of the studied pharmaceuticals on the plant metabolism (enzymes of Hatch-Slack cycle, peroxidases) was followed. The activity of bound peroxidases, which could cause xylem vessel lignification and reduction of xenobiotic uptake, was at the level of control plants in maize leaves contrary to sunflower. Therefore, our results indicate that maize has the potential to remove 10,11-epoxycarbamazepine from contaminated soils.

• MeSH
• antikonvulziva analýza   metabolismus   MeSH
• biodegradace MeSH
• Helianthus účinky léků   růst a vývoj   metabolismus   MeSH
• hydroponie MeSH
• karbamazepin analogy a deriváty   analýza   metabolismus   MeSH
• kukuřice setá účinky léků   růst a vývoj   metabolismus   MeSH
• látky znečišťující půdu analýza   metabolismus   MeSH
• listy rostlin účinky léků   růst a vývoj   metabolismus   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

• Klíčová slova
• vepřové sádlo - nejstabilnější, řepkový olej, oxidační produkty, polymerační produkty,
• MeSH
• Brassica napus * chemie   metabolismus   škodlivé účinky   MeSH
• chromatografie * metody   využití   MeSH
• Helianthus * chemie   metabolismus   škodlivé účinky   MeSH
• kvalita jídla * MeSH
• lidé MeSH
• nenasycené mastné kyseliny * MeSH
• oleje rostlin * analýza   chemie   metabolismus   škodlivé účinky   MeSH
• oxidace-redukce * MeSH
• refraktometrie * metody   normy   využití   MeSH
• slunečnicový olej MeSH
• statistika jako téma MeSH
• tokoferoly * analýza   metabolismus   MeSH
• triglyceridy * analýza   chemie   metabolismus   škodlivé účinky   MeSH
• tuky * analýza   chemie   metabolismus   škodlivé účinky   MeSH
• vysoká teplota * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

BACKGROUND AND AIMS: Stomatal density (SD) generally decreases with rising atmospheric CO2 concentration, Ca. However, SD is also affected by light, air humidity and drought, all under systemic signalling from older leaves. This makes our understanding of how Ca controls SD incomplete. This study tested the hypotheses that SD is affected by the internal CO2 concentration of the leaf, Ci, rather than Ca, and that cotyledons, as the first plant assimilation organs, lack the systemic signal. METHODS: Sunflower (Helianthus annuus), beech (Fagus sylvatica), arabidopsis (Arabidopsis thaliana) and garden cress (Lepidium sativum) were grown under contrasting environmental conditions that affected Ci while Ca was kept constant. The SD, pavement cell density (PCD) and stomatal index (SI) responses to Ci in cotyledons and the first leaves of garden cress were compared. (13)C abundance (δ(13)C) in leaf dry matter was used to estimate the effective Ci during leaf development. The SD was estimated from leaf imprints. KEY RESULTS: SD correlated negatively with Ci in leaves of all four species and under three different treatments (irradiance, abscisic acid and osmotic stress). PCD in arabidopsis and garden cress responded similarly, so that SI was largely unaffected. However, SD and PCD of cotyledons were insensitive to Ci, indicating an essential role for systemic signalling. CONCLUSIONS: It is proposed that Ci or a Ci-linked factor plays an important role in modulating SD and PCD during epidermis development and leaf expansion. The absence of a Ci-SD relationship in the cotyledons of garden cress indicates the key role of lower-insertion CO2 assimilation organs in signal perception and its long-distance transport.

• MeSH
• Arabidopsis cytologie   účinky léků   MeSH
• buk (rod) cytologie   účinky léků   MeSH
• dehydratace MeSH
• Helianthus cytologie   účinky léků   MeSH
• kotyledon účinky léků   fyziologie   MeSH
• Lepidium cytologie   účinky léků   MeSH
• oxid uhličitý farmakologie   MeSH
• počet buněk MeSH
• průduchy rostlin cytologie   účinky léků   MeSH
• životní prostředí MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A prototype capable of generating underwater high-voltage discharges (3.5 kV) coupled with water plasma expansion was constructed. The level of phytomass disintegration caused by transmission of the pressure shockwaves (50-60 MPa) followed by this expansion was analyzed using gas adsorption techniques. The dynamics of the external surface area and the micropore volume on multiple pretreatment stages of maize silage and sunflower seeds was approximated with robust analytical techniques. The multiple increases on the reaction surface were manifest in up to a 15% increase in cumulative methane production, which was itself manifest in the overall acceleration of the anaerobic fermentation process. Disintegration of the sunflower seeds allowed up to 45% higher oil yields using the same operating pressure.

• MeSH
• biomasa * MeSH
• biopaliva MeSH
• elektřina * MeSH
• Helianthus MeSH
• kukuřice setá MeSH
• tlak MeSH
• voda MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Background and Objectives: The development in the technology have witnessed that there is a revival of interest in drug discovery from medicinal plants for treatment of the most destructive diseases. Our investigation characterizes the usage of digital image processing techniques in Matlab to process and analyze the antimicrobial effects of the selected herbal plants. Methods: The first stage of our investigation involves the extraction of components with methanol from the selected three herbal plants- Solanum xanthocarpum, Solanum nigrum and Helianthus annuus by using soxhlet apparatus. These plant extracts were assayed for antimicrobial activity against 4 different bacterial and fungal species using disk diffusion method. Results: Notable cell growth inhibitions were observed from the selected microbes. Solanum xanthocarpum exhibits better antibacterial properties on comparison to other two extracts. Solanum nigrum and Helianthus annuus exhibit better antifungal properties by being sensitive factor towards fungal medium. The obtained images were processed using color coding techniques to determine the activity of the extract by isolating the region of inhibition area. The region of inhibition was measured using matlab code and tabulation was compiled to compare the manually measured distances to the automated measurements. Conclusions: The results provided evidence that the studied plant extracts might indeed be potential sources of natural antimicrobial agents and the introduction of an evaluation technique using image processing was shown to be suitable for the purpose of accurate measurements of zone of inhibition.

• MeSH
• agar MeSH
• antibakteriální látky * farmakokinetika   farmakologie   terapeutické užití   MeSH
• antifungální látky * farmakokinetika   farmakologie   izolace a purifikace   MeSH
• fytoterapie * metody   statistika a číselné údaje   MeSH
• Helianthus MeSH
• léčivé rostliny MeSH
• počítače statistika a číselné údaje   využití   MeSH
• rostlinné extrakty * farmakokinetika   farmakologie   MeSH
• Solanum MeSH