BACKGROUND: The species of the Hypericum genus are markedly variable in morphological, physiological and biochemical traits. They significantly differ in their area of distribution, which may determine their natural tolerance to environmental conditions, such as temperature extremes. OBJECTIVE: To test the hypothesis that the species growing worldwide in different regions and altitudes would be better able to withstand cryopreservation than the endemics. METHODS: The frost tolerance of 10 selected Hypericum species was evaluated. A possible stimulatory effect of cold-acclimation and vitrification-associated stressors on the content of hypericins was also investigated RESULTS: We found that frost tolerance of 10 selected Hypericum species expressed by LT50 ranged between -11 degree C for the species occurring worldwide and -4 degree C for sub/tropical frost sensitive taxons which corresponded with their natural habitats. CONCLUSIONS: Although the mean recoveries for all species cryopreserved with the same vitrification procedure did not exceed 30%, the effect of genetic predisposition to cold tolerance should be considered for optimisation of cryopreservation protocol. Our data neither proved an elicitation effect of cold on hypericin biosynthesis, nor correlation between hypericin content and quantitative characteristics of the hypericin-accumulating black nodules.

• MeSH
• aklimatizace MeSH
• druhová specificita MeSH
• kryoprezervace MeSH
• nadmořská výška MeSH
• nízká teplota MeSH
• třezalka fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• aklimatizace MeSH
• časové faktory MeSH
• finanční podpora výzkumu jako téma MeSH
• pšenice genetika   růst a vývoj   MeSH
• roční období MeSH
• výhonky rostlin MeSH

We report a series of microarray-based leaf and crown transcriptome comparisons involving three barley cultivars (cvs. Luxor, Igri and Atlas 68) which express differing degrees of frost tolerance. The transcripts were obtained following the exposure of seedlings to low (above and below zero) temperatures, aiming to identify those genes and signalling/metabolic pathways which are associated with frost tolerance. Both the leaves and the crowns responded to low temperature by the up-regulation of a suite of abscisic acid (ABA)-responsive genes, most of which have already been recognized as components of the plant low temperature response. The inter-cultivar comparison indicated that genes involved in maintaining the leaf's capacity to synthesize protein and to retain chloroplast activity were important for the expression of frost tolerance. In the crown, the repression of genes associated with nucleosome assembly and transposon regulation were the most relevant transcriptional changes associated with frost tolerance, highlighting the role of gene repression in the cold acclimation response.

• MeSH
• down regulace MeSH
• ječmen (rod) genetika   metabolismus   MeSH
• listy rostlin genetika   metabolismus   MeSH
• mapování chromozomů MeSH
• nukleozomy genetika   metabolismus   MeSH
• reakce na chladový šok MeSH
• regulace genové exprese u rostlin MeSH
• rostlinné geny MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• transkripční elongační faktory genetika   metabolismus   MeSH
• transkriptom MeSH
• upregulace MeSH
• zmrazování MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Five winter oilseed rape cultivars (Benefit, Californium, Cortes, Ladoga, Navajo) were subjected to 30 days of cold treatment (4 °C) to examine the effect of cold on acquired frost tolerance (FT), dehydrin (DHN) content, and photosynthesis-related parameters. The main aim of this study was to determine whether there are relationships between FT (expressed as LT50 values) and the other parameters measured in the cultivars. While the cultivar Benefit accumulated two types of DHNs (D45 and D35), the other cultivars accumulated three additional DHNs (D97, D47, and D37). The similar-sized DHNs (D45 and D47) were the most abundant; the others exhibited significantly lower accumulations. The highest correlations were detected between LT50 and DHN accumulation (r=-0.815), intrinsic water use efficiency (WUEi; r=-0.643), net photosynthetic rate (r=-0.628), stomatal conductance (r=0.511), and intracellular/intercellular CO2 concentration (r=0.505). Those cultivars that exhibited higher Pn rate in cold (and further a significant increase in WUEi) had higher levels of DHNs and also higher FT. No significant correlation was observed between LT50 and E, PRI, or NDVI. Overall, we have shown the selected physiological parameters to be able to distinguish different FT cultivars of winter oilseed rape.

• MeSH
• aklimatizace MeSH
• analýza hlavních komponent MeSH
• analýza rozptylu MeSH
• Brassica napus fyziologie   MeSH
• fotosyntéza fyziologie   MeSH
• fyziologická adaptace * MeSH
• roční období * MeSH
• rostlinné proteiny metabolismus   MeSH
• voda fyziologie   MeSH
• zmrazování * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The dynamics of a long-term cold acclimation (CA) was studied in spring barley cultivar Atlas 68, winter barley cultivar Igri and a set of doubled haploid (DH) lines derived from an Atlas 68xIgri cross. The aim was to evaluate the effect of plant development on the ability to induce frost tolerance (FT) and to accumulate dehydrin 5 (DHN5) during CA. The plant developmental stage was evaluated by phenological development of the shoot apex and by determination of days to heading after a certain period of CA. FT was determined by direct frost tests. Plant winter survival was also determined. DHN5 was evaluated by densitometric analysis of protein gel blots. Cold led to the induction of increased FT and to the accumulation of DHN5 in both spring and winter lines. However, with the progression of CA, differences between the growth habits occurred as the winter lines were able to maintain increased FT and DHN5 levels for a significantly longer period of time than the spring lines. After vegetative/reproductive transition, a significant decrease in DHN5 accumulation was found in all lines; however, a discrepancy between the acquired FT level and DHN5 accumulation in vernalized winter barley plants was found. A correlation between DHN5 accumulation and plant winter survival was found when the studied lines were differentiated according to their developmental stage and DHN5 level. Possible explanations for these phenomena are provided.

• MeSH
• aklimatizace genetika   fyziologie   MeSH
• chov MeSH
• haploidie MeSH
• ječmen (rod) genetika   fyziologie   MeSH
• listy rostlin metabolismus   fyziologie   MeSH
• nízká teplota MeSH
• rostlinné proteiny biosyntéza   genetika   metabolismus   MeSH
• výhonky rostlin fyziologie   MeSH
• zmrazování MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Dynamics of cold tolerance and crown proteome composition has been analysed in a set of two winter wheat cultivars Mironovskaya 808 and Bezostaya 1 and four reciprocal substitution lines with interchanged chromosomes 5A and 5B during a long-term cold-acclimation (CA) treatment. Proteome analysis has revealed 298 differently abundant spots during experiment. Most of them (260) were changed due to CA process and only 52 spots displayed differences between genotypes. Two hundred and seven protein spots were successfully identified by tandem mass spectrometry. Comparison of samples before and after vernalization fulfillment by a combination of ANOVA and Student' T-test displayed ten differentially abundant protein spots (e.g. chopper chaperones). However, differences in the accumulation of these spots did not reflect differences in vernalization requirement of genotypes. Therefore, our results indicate that vernalization process has not influenced total proteome of CA wheat crowns. A few protein spots (14 spots; e.g. malate dehydrogenase) revealed differential accumulation levels between the individual genotypes or their groups possessing chromosome 5A or 5B from Mironovskaya 808 versus Bezostaya 1. The study has shown the effect of chromosome 5A on physiological traits and also proteome in winter wheat. Putative candidate protein markers for cold tolerance in wheat are discussed.

• MeSH
• analýza hlavních komponent MeSH
• chromozomy rostlin MeSH
• dvourozměrná diferenční gelová elektroforéza MeSH
• fenotyp MeSH
• fyziologická adaptace genetika   MeSH
• metabolické sítě a dráhy MeSH
• nízká teplota MeSH
• proteom genetika   metabolismus   MeSH
• pšenice genetika   metabolismus   fyziologie   MeSH
• regulace genové exprese u rostlin MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• shluková analýza MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Winter barley is an economically important cereal crop grown in higher latitudes and altitudes where low temperatures represent an important environmental constraint limiting crop productivity. In this study changes in proteome of leaves and crowns in a frost tolerant winter barley cv. Luxor in relation to short and long term periods of cold followed by a brief frost treatment were studied in order to disclose proteins responsible for the cold hardening process in distinct plant tissues. The mentioned changes have been monitored using two dimensional difference gel electrophoresis (2D-DIGE) with subsequent peptide-mapping protein identification. Regarding approximately 600-700 distinct protein spots detected on 2D gels, there has been found at least a two-fold change after exposure to low temperatures in about 10% of proteins in leaves and 13% of proteins in crowns. Protein and nitrogen metabolic processes have been influenced by low temperature to a similar extent in both tissues while catabolism, carbohydrate metabolism and proteins involved in stress response have been more affected in crowns than in leaves. The range of changes in protein abundance was generally higher in leaves and chloroplast proteins were frequently affected which suggests a priority to protect photosynthetic apparatus. Overall, our data proved existence of slightly different response strategies to low temperature stress in crowns and leaves, i.e., tissues with different biological role. Moreover, there have been found several proteins with large increase in accumulation, e.g., 33 kDa oxygen evolving protein of photosystem II in leaves and "enhanced disease susceptibility 1" in crowns; these proteins might have potential to indicate an enhanced level of frost tolerance in barley.

• Publikační typ
• časopisecké články MeSH

A new rhabdocoel of the genus Syndesmis Silliman, 1881 (Umagillidae) is described from the intestine of the New Zealand sea urchin Evechinus chloroticus (Valenciennes, 1846) Mortensen, 1943a. This new species, Syndesmis kurakaikina n. sp., is morphologically distinct and can easily be recognised by its very long (±1 mm) stylet and its bright-red colour. In addition to providing a formal description, we present some observations on reproduction and life history of this new species. Fecundity is comparable to that of other umagillids and the rate of egg production and development increases with temperature. Hatching in this species is induced by intestinal fluids of its host. Relevant to global warming, we assessed the effect of temperature on survival, fecundity, and development. The tests indicate that Syndesmis kurakaikina n. sp. is tolerant of a wide range of temperatures (11-25 °C) and that its temperature optimum lies between 18.0 and 21.5 °C. Egg viability is, however, significantly compromised at the higher end of this temperature range, with expelled egg capsules often being deformed and showing increasingly lower rates of hatching. Given this, a rise in global temperature might increase the risk of Syndesmis kurakaikina n. sp. infecting new hosts and would possibly facilitate the spread of these endosymbionts.

• Publikační typ
• časopisecké články MeSH

The development of an ideal vascular prosthesis represents an important challenge in terms of the treatment of cardiovascular diseases with respect to which new materials are being considered that have produced promising results following testing in animal models. This study focuses on nanofibrous polycaprolactone-based grafts assessed by means of histological techniques 10 days and 6 months following suturing as a replacement for the rat aorta. A novel stereological approach for the assessment of cellular distribution within the graft thickness was developed. The cellularization of the thickness of the graft was found to be homogeneous after 10 days and to have changed after 6 months, at which time the majority of cells was discovered in the inner layer where the regeneration of the vessel wall was found to have occurred. Six months following implantation, the endothelialization of the graft lumen was complete, and no vasa vasorum were found to be present. Newly formed tissue resembling native elastic arteries with concentric layers composed of smooth muscle cells, collagen, and elastin was found in the implanted polycaprolactone-based grafts. Moreover, the inner layer of the graft was seen to have developed structural similarities to the regular aortic wall. The grafts appeared to be well tolerated, and no severe adverse reaction was recorded with the exception of one case of cartilaginous metaplasia close to the junctional suture.

• Publikační typ
• časopisecké články MeSH

Hormonal changes accompanying the cold stress (4°C) response that are related to the level of frost tolerance (FT; measured as LT50) and the content of the most abundant dehydrin, WCS120, were compared in the leaves and crowns of the winter wheat (Triticum aestivum L.) cv. Samanta and the spring wheat cv. Sandra. The characteristic feature of the alarm phase (1 day) response was a rapid elevation of abscisic acid (ABA) and an increase of protective proteins (dehydrin WCS120). This response was faster and stronger in winter wheat, where it coincided with the downregulation of bioactive cytokinins and auxin as well as enhanced deactivation of gibberellins, indicating rapid suppression of growth. Next, the ethylene precursor aminocyclopropane carboxylic acid was quickly upregulated. After 3-7 days of cold exposure, plant adaptation to the low temperature was correlated with a decrease in ABA and elevation of growth-promoting hormones (cytokinins, auxin and gibberellins). The content of other stress hormones, i.e., salicylic acid and jasmonic acid, also began to increase. After prolonged cold exposure (21 days), a resistance phase occurred. The winter cultivar exhibited substantially enhanced FT, which was associated with a decline in bioactive cytokinins and auxin. The inability of the spring cultivar to further increase its FT was correlated with maintenance of a relatively higher cytokinin and auxin content, which was achieved during the acclimation period.

• MeSH
• aklimatizace MeSH
• analýza hlavních komponent MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• listy rostlin enzymologie   MeSH
• nízká teplota MeSH
• oxidoreduktasy metabolismus   MeSH
• pšenice fyziologie   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• roční období MeSH
• rostlinné proteiny metabolismus   MeSH
• zmrazování MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH