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11.
Bettina Ughy Vclav Karlický Ondej Dlouhý Uro Javornik Zuzana Materov Ott Zsiros Primo ket Janez Plavec Vladimír punda Gyz Garab 《Physiologia plantarum》2019,166(1):278-287
Earlier experiments, using 31P‐NMR and time‐resolved merocyanine fluorescence spectroscopy, have shown that isolated intact, fully functional plant thylakoid membranes, in addition to the bilayer phase, contain three non‐bilayer (or non‐lamellar) lipid phases. It has also been shown that the lipid polymorphism of thylakoid membranes can be characterized by remarkable plasticity, i.e. by significant variations in 31P‐NMR signatures. However, changes in the lipid‐phase behaviour of thylakoids could not be assigned to changes in the overall membrane organization and the photosynthetic activity, as tested by circular dichroism and 77 K fluorescence emission spectroscopy and the magnitude of the variable fluorescence of photosystem II, which all showed only marginal variations. In this work, we investigated in more detail the temporal stability of the different lipid phases by recording 31P‐NMR spectra on isolated thylakoid membranes that were suspended in sorbitol‐ or NaCl‐based media. We observed, at 5°C during 8 h in the dark, substantial gradual enhancement of the isotropic lipid phases and diminishment of the bilayer phase in the sorbitol‐based medium. These changes compared well with the gradually increasing membrane permeability, as testified by the gradual acceleration of the decay of flash‐induced electrochromic absorption changes and characteristic changes in the kinetics of fast chlorophyll a‐fluorescence transients; all variations were much less pronounced in the NaCl‐based medium. These observations suggest that non‐bilayer lipids and non‐lamellar lipid phases play significant roles in the structural dynamics and functional plasticity of thylakoid membranes. 相似文献
12.
Binu Timsina Maan B. Rokaya Zuzana Münzbergová Pavel Kindlmann Bikram Shrestha Bishnu Bhattarai Bhakta B. Raskoti 《Biodiversity and Conservation》2016,25(13):2803-2819
Associations between epiphytes and their hosts are among the main factors affecting the biodiversity and distribution of epiphytes. While several previous studies explored the association between epiphyte diversity and host characteristics, very little is known about the generality of such associations at larger spatial scales. We aim to explore the associations between diversity and distribution of epiphytic orchids and host characteristics in different localities in Nepal. Epiphytic orchids and their hosts were recorded along the transects in total of 23,539 host individuals. To describe the diversity of orchids in the different localities, a rarefaction function was used. Univariate and multivariate analyses were carried out to explore the associations with locality, host characteristics, and their interactions with locality. In total, we recorded 141 species of orchids growing on 192 host species. The five localities significantly differed in orchid diversity and abundance. The number of orchid individuals per host species significantly increased with increasing number of host individuals. Species richness, abundances, occupancy of orchid species on host species and composition of orchids varied across the localities. Species richness and abundance was significantly higher on hosts in the higher strata and differed between families of host species. Abundance was higher on evergreen hosts. Composition of orchid communities are also associated with host characteristics, such as habit (shrub/tree/climber), bark texture, nature (deciduous/evergreen) and the plant families of host species. This study revealed a high diversity of epiphytic orchids in the localities studied and strong associations between the orchids and their hosts. Future studies looking at the relationships between epiphyte communities and host characteristics need to identify relationships at a wider scale in order to determine whether they are really general rather than site-specific. 相似文献
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Rositsa S. Milcheva Svetlozara L. Petkova Pavol Dubinsky Zuzana Hurniková Pavel Babál 《Biologia》2009,64(1):180-186
The in situ identification of carbohydrate structures in Trichinella spiralis intestinal larvae, adults and L1 muscular larvae was carried out by lectin histochemistry, with emphasis on the O-linked
glycans. The absence of reactivity with two lectins-TML and MAL indicated that Trichinella spiralis does not synthesize sialic acid. Reactivity with HPA, VVL-B4, PNA and UEA-I staining suggested that T. spiralis synthesizes and expresses on its cuticle O-linked glycans analogous to Tn-antigen (GalNAc-α-Ser/Thr), T-antigen (Gal-β1,3-GalNAc-α-Ser/Thr) and also structures analogous to A-blood group antigens (GalNAc-α1,3-Gal-β1,3(4)-(Fuc-α1,2-)-R). Expression of the saccharidic moieties is stage-specific. Blood group-A and T-antigen structures were identified
on the cuticle of the intestinal and muscular larvae. The Tn-antigen structure was missing in the intestinal larvae. Appropriate
ligands for WGA were not identified in the adult individuals. The obtained results may contribute to a better understanding
of the glycobiology of this parasitic nematode in relation to occupation of its intracellular niche. The presence of saccharidic
structures analogous to some of those expressed on the intestinal epithelial cells may serve as a protective shield on the
surface of the parasite. 相似文献
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Zuzana Chumová Eliška Záveská Petra Hloušková Jan Ponert Philipp-André Schmidt Martin Čertner Terezie Mandáková Pavel Trávníček 《The Plant journal : for cell and molecular biology》2021,107(2):511-524
Although the evolutionary drivers of genome size change are known, the general patterns and mechanisms of plant genome size evolution are yet to be established. Here we aim to assess the relative importance of proliferation of repetitive DNA, chromosomal variation (including polyploidy), and the type of endoreplication for genome size evolution of the Pleurothallidinae, the most species-rich orchid lineage. Phylogenetic relationships between 341 Pleurothallidinae representatives were refined using a target enrichment hybrid capture combined with high-throughput sequencing approach. Genome size and the type of endoreplication were assessed using flow cytometry supplemented with karyological analysis and low-coverage Illumina sequencing for repeatome analysis on a subset of samples. Data were analyzed using phylogeny-based models. Genome size diversity (0.2–5.1 Gbp) was mostly independent of profound chromosome count variation (2n = 12–90) but tightly linked with the overall content of repetitive DNA elements. Species with partial endoreplication (PE) had significantly greater genome sizes, and genomic repeat content was tightly correlated with the size of the non-endoreplicated part of the genome. In PE species, repetitive DNA is preferentially accumulated in the non-endoreplicated parts of their genomes. Our results demonstrate that proliferation of repetitive DNA elements and PE together shape the patterns of genome size diversity in orchids. 相似文献
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Simulation of seed passage through a bird’s gut is an important tool for comparing the effect of bird digestion and thus the potential for plant dispersal by endozoochory. However, sufficient methodology is missing. Thus, we subjected seeds of 20 plant species to seven different simulations of gut passage and to the real passage through a pigeon’s gut to determine which simulation type best reflects the effects of real bird digestion. We also measured various seed traits to identify the traits responsible for differences between species. Results show that four out of seven simulations were significant predictors of seed survival after gut passage. The fit between direct digestion by the pigeon and the different simulation treatments was, however, species-specific and depends not only on the commonly tested traits such as seed mass and water permeability, but also on other unmeasured traits. Seed mass was the best predictor of differences between real digestion and simulation. Selecting one type of simulation to be a good predictor of seed survival after gut passage is difficult. The strongest simulation (24-h scarification and 240-min acid immersion) is the best predictor and may be used to compare the ability of seeds to be dispersed by bird endozoochory. Such knowledge can be included in databases of species traits, as is currently done for many other species traits. 相似文献
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20.
Jaroslav Pavel Zuzana Oroszova Ludmila Hricova Nadezda Lukacova 《Cellular and molecular neurobiology》2013,33(5):681-688
To clarify the role of angiotensin II (Ang II) in the regulation of sensory signaling, we studied the effect of subpressor dose (150 ng/kg/min) of Ang II on pain-related behavior in relation with neuronal injury and activation of satellite glial cells (SGCs) in the dorsal root ganglia (DRGs) after chronic constriction injury (CCI). Systemic continuous delivery of Ang II induced the tactile, heat and cold hyperlagesia, when measured at 7 days ofpost-injury. Blockade of the AT1 receptor with losartan (2.5 mg/kg/day) prevented tactile hyperalgesia and attenuated cold hyperalgesia, but did not affect the response to noxious heat stimulus. A marked increase of large-sized injured primary afferent neurons, detected by ATF3 immunolabeling, was seen in lower lumbar DRGs on ipsilateral side after Ang II treatment. Subpressor dose of Ang II induced an increase of activated SGCs (detected by GFAP immunolabeling) enveloping large-diameter neurons. Our results suggested that Ang II through the AT1 receptor activation is an important regulatory factor in neuropathic pain perception and plays an important role in the injury of large-sized primary afferent neurons and activation of SGCs elicited by the CCI. 相似文献