BACKGROUND: The plant hormone auxin is a major coordinator of plant growth and development in response to diverse environmental signals, including nutritional conditions. Sole ammonium (NH4+) nutrition is one of the unique growth-suppressing conditions for plants. Therefore, the quest to understand NH4+-mediated developmental defects led us to analyze auxin metabolism. RESULTS: Indole-3-acetic acid (IAA), the most predominant natural auxin, accumulates in the leaves and roots of mature Arabidopsis thaliana plants grown on NH4+, but not in the root tips. We found changes at the expressional level in reactions leading to IAA biosynthesis and deactivation in different tissues. Finally, NH4+ nutrition would facilitate the formation of inactive oxidized IAA as the final product. CONCLUSIONS: NH4+-mediated accelerated auxin turnover rates implicate transient and local IAA peaks. A noticeable auxin pattern in tissues correlates with the developmental adaptations of the short and highly branched root system of NH4+-grown plants. Therefore, the spatiotemporal distribution of auxin might be a root-shaping signal specific to adjust to NH4+-stress conditions.

• Klíčová slova
• Ammonium nutrition, Arabidopsis thaliana, Auxin conjugation, Auxin degradation, Auxin synthesis, Root development,
• MeSH
• amoniové sloučeniny metabolismus   MeSH
• Arabidopsis metabolismus   MeSH
• časoprostorová analýza MeSH
• fyziologický stres MeSH
• kořeny rostlin metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• metabolismus MeSH
• oxidace-redukce MeSH
• tkáňová distribuce MeSH
• výhonky rostlin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amoniové sloučeniny MeSH
• indoleacetic acid MeSH Prohlížeč
• kyseliny indoloctové MeSH

Myeloid phagocytes have evolved to rapidly recognize invading pathogens and clear them through opsonophagocytic killing. The adenylate cyclase toxin (CyaA) of Bordetella pertussis and the edema toxin (ET) of Bacillus anthracis are both calmodulin-activated toxins with adenylyl cyclase activity that invade host cells and massively increase the cellular concentrations of a key second messenger molecule, 3',5'-cyclic adenosine monophosphate (cAMP). However, the two toxins differ in the kinetics and mode of cell entry and generate different cAMP concentration gradients within the cell. While CyaA rapidly penetrates cells directly across their plasma membrane, the cellular entry of ET depends on receptor-mediated endocytosis and translocation of the enzymatic subunit across the endosomal membrane. We show that CyaA-generated membrane-proximal cAMP gradient strongly inhibits the activation and phosphorylation of Syk, Vav, and Pyk2, thus inhibiting opsonophagocytosis. By contrast, at similar overall cellular cAMP levels, the ET-generated perinuclear cAMP gradient poorly inhibits the activation and phosphorylation of these signaling proteins. Hence, differences in spatiotemporal distribution of cAMP produced by the two adenylyl cyclase toxins differentially affect the opsonophagocytic signaling in myeloid phagocytes.

• Klíčová slova
• 3′,5′-cyclic adenosine monophosphate (cAMP), Pyk2, Syk, Vav, adenylate cyclase toxin, edema toxin, opsonophagocytosis, phagocytes, signaling pathway,
• MeSH
• adenylátcyklasový toxin toxicita   MeSH
• AMP cyklický metabolismus   MeSH
• antigeny bakteriální toxicita   MeSH
• bakteriální toxiny toxicita   MeSH
• časoprostorová analýza MeSH
• fagocytóza účinky léků   MeSH
• fagocyty účinky léků   metabolismus   MeSH
• fosforylace účinky léků   MeSH
• lidé MeSH
• mikrofilamenta účinky léků   MeSH
• opsoniny farmakologie   MeSH
• receptory imunologické metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• THP-1 buňky MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenylátcyklasový toxin MeSH
• AMP cyklický MeSH
• anthrax toxin MeSH Prohlížeč
• antigeny bakteriální MeSH
• bakteriální toxiny MeSH
• opsonin receptor MeSH Prohlížeč
• opsoniny MeSH
• receptory imunologické MeSH

Exploration of interactions between hosts and parasitic symbionts is important for our understanding of the temporal and spatial distribution of organisms. For example, host colonization of new geographical regions may alter levels of infections and parasite specificity, and even allow hosts to escape from co-evolved parasites, consequently shaping spatial distributions and community structure of both host and parasite. Here we investigate the effect of host colonization of new regions and the elevational distribution of host-parasite associations between birds and their vector-transmitted haemosporidian blood parasites in two geological and geographical settings: mountains of New Guinea and the Canary Islands. Our results demonstrate that bird communities in younger regions have significantly lower levels of parasitism compared to those of older regions. Furthermore, host-parasite network analyses demonstrate that blood parasites may respond differently after arriving to a new region, through adaptations that allow for either expanding (Canary Islands) or retaining (New Guinea) their host niches. The spatial prevalence patterns along elevational gradients differed in the two regions, suggesting that region-specific biotic (e.g., host community) and abiotic factors (e.g., temperature) govern prevalence patterns. Our findings suggest that the spatiotemporal range dynamics in host-parasite systems are driven by multiple factors, but that host and parasite community compositions and colonization histories are of particular importance.

• Klíčová slova
• Canary Islands, New Guinea, avian malaria, elevational gradients, haemosporidians,
• MeSH
• časoprostorová analýza MeSH
• Haemosporida * MeSH
• interakce hostitele a parazita * MeSH
• ptáci parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Nová Guinea MeSH
• Španělsko MeSH

Fluorescent selective probes for reactive oxygen species (ROS) detection in living cells are versatile tools for the documentation of ROS production in plant developmental or stress reactions. We employed high-resolution live-cell imaging and semiquantitative analysis of Arabidopsis (Arabidopsis thaliana) stained with CM-H2DCFDA, CellROX Deep Red, and Amplex Red for functional characterization of the spatiotemporal mode of ROS production, delivery, and utilization during root hair formation. Cell viability marker fluorescein diacetate served as a positive control for dye loading and undisturbed root hair tip growth after staining. Using a colocalization analysis with subcellular molecular markers and two root hair mutants with similar phenotypes of nonelongating root hairs, but with contrasting reasons for this impairment, we found that: (i) CM-H2DCFDA is a sensitive probe for ROS generation in the cytoplasm, (ii) CellROX Deep Red labels ROS in mitochondria, (iii) Amplex Red labels apoplastic ROS and mitochondria and shows high selectivity to root hairs, (iv) the root hair defective 2-1 (rhd2-1) mutant with nonfunctional NADPH oxidase RESPIRATORY BURST OXIDASE HOMOLOG PROTEIN C/ROOT HAIR-DEFECTIVE 2 (AtRBOHC/RHD2) has a low level of CM-H2DCFDA-reactive ROS in cytoplasm and lacks Amplex Red-reactive ROS in apoplast, and (v) the ACTIN2-deficient deformed root hairs1-3 (der1-3) mutant is not altered in these aspects. The sensitivity of CellROX Deep Red was documented by discrimination between larger ROS-containing mitochondria and small, yet ROS-free premature mitochondria in the growing tip of root hairs. We characterized spatial changes in ROS production and compartmentalization induced by external ROS modulators, ethylene precursor 1-aminocyclopropane-1-carboxylic acid, and ionophore valinomycin. This dynamic and high-resolution study of ROS production and utilization opens opportunities for precise speciation of particular ROS involved in root hair formation.

• MeSH
• Arabidopsis * metabolismus   MeSH
• fenotyp MeSH
• kořeny rostlin metabolismus   MeSH
• proteiny huseníčku * genetika   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 2',7'-dichlorodihydrofluorescein diacetate MeSH Prohlížeč
• proteiny huseníčku * MeSH
• reaktivní formy kyslíku MeSH

High concentrations of naturally-occurring and man-accentuated boron in groundwater possess a potential threat to the health and well-being of humans worldwide. In Bangladesh, only a few studies focused on the health risks of boron-containing groundwater. Therefore, the present study investigated the spatiotemporal distribution of boron concentrations in groundwater and its associated health risks in the coastal districts of Bangladesh. A total of 268 samples from the shallow and deep wells during the wet and dry season (137 and 131 samples, respectively) were collected to determine the level of boron concentrations and health risk status. The groundwater boron concentrations ranged from 0 to 4.10 mg/L with an average concentration of 0.68 mg/L, which was much lower than the WHO and the values of Bangladesh drinking water standard guideline. The boron concentrations in the shallow wells override the deep ones with insignificant seasonal variation. Boron contamination affected 10% of the shallow wells in the wet season and only 6% of them in the dry season, whereas only 1% of deep wells exceeds the WHO guideline values of 2.40 mg/L during the wet and dry season, respectively. The human health risk of boron was determined by computing estimated daily intake (EDI) and hazard quotient (HQ) values for infants, children, teenagers, and adults. The average HQ value delimitated that children have high risk followed by teenagers, adults, and infants. About 90-95% of the studied samples were free from boron contamination because of having HQ values < 1 and the rest of the samples possess a high risk for children. For the overall study area, the deep wells were found safer than the shallow wells, which were more susceptible to boron contamination aided by localized freshwater inputs.

• Klíčová slova
• Boron enrichment, Coastal zone of Bangladesh, Groundwater, Hazard quotient, Health risk, Pearson correlation,
• MeSH
• bor MeSH
• chemické látky znečišťující vodu * analýza   MeSH
• dítě MeSH
• dospělí MeSH
• hodnocení rizik MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• monitorování životního prostředí MeSH
• podzemní voda * MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Bangladéš MeSH
• Názvy látek
• bor MeSH
• chemické látky znečišťující vodu * MeSH

Polycyclic aromatic hydrocarbons (PAHs) are common atmospheric pollutants and known to cause adverse health effects. Nitrated PAHs (NPAHs) are formed in combustion activities and by nitration of PAHs in the atmosphere and may be equally or more toxic, but their spatial and temporal distribution in the atmosphere is not well characterized. Using the global EMAC model with atmospheric chemistry and surface compartments coupled, we investigate the formation, abundance, and fate of two secondarily formed NPAHs, 2-nitrofluoranthene (2-NFLT) and 2-nitropyrene (2-NPYR). The default reactivity scenario, the model with the simplest interpretation of parameters from the literature, tends to overestimate both absolute concentrations and NPAH/PAH ratios at observational sites. Sensitivity scenarios indicate that NO2-dependent NPAH formation leads to better agreement between measured and predicted NPAH concentrations and that photodegradation is the most important loss process of 2-NFLT and 2-NPYR. The highest concentrations of 2-NFLT and 2-NPYR are found in regions with strong PAH emissions, but because of continued secondary formation from the PAH precursors, these two NPAHs are predicted to be spread across the globe.

• MeSH
• atmosféra MeSH
• fluoreny MeSH
• látky znečišťující vzduch * analýza   MeSH
• monitorování životního prostředí MeSH
• polycyklické aromatické uhlovodíky * analýza   MeSH
• pyreny MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 2-nitrofluoranthene MeSH Prohlížeč
• 2-nitropyrene MeSH Prohlížeč
• fluoreny MeSH
• látky znečišťující vzduch * MeSH
• polycyklické aromatické uhlovodíky * MeSH
• pyreny MeSH

Color polymorphism offers rich opportunities for studying the eco-evolutionary mechanisms that drive the adaptations of local populations to heterogeneous and changing environments. We explored the color morph diversity and composition in a Chrysomela lapponica leaf beetle across its entire distribution range to test the hypothesis that environmental and climatic variables shape spatiotemporal variation in the phenotypic structure of a polymorphic species. We obtained information on 13 617 specimens of this beetle from museums, private collections, and websites. These specimens (collected from 1830-2020) originated from 959 localities spanning 33° latitude, 178° longitude, and 4200 m altitude. We classified the beetles into five color morphs and searched for environmental factors that could explain the variation in the level of polymorphism (quantified by the Shannon diversity index) and in the relative frequencies of individual color morphs. The highest level of polymorphism was found at high latitudes and altitudes. The color morphs differed in their climatic requirements; composition of colour morphs was independent of the geographic distance that separated populations but changed with collection year, longitude, mean July temperature and between-year temperature fluctuations. The proportion of melanic beetles, in line with the thermal melanism hypothesis, increased with increasing latitude and altitude and decreased with increasing climate seasonality. Melanic morph frequencies also declined during the past century, but only at high latitudes and altitudes where recent climate warming was especially strong. The observed patterns suggest that color polymorphism is especially advantageous for populations inhabiting unpredictable environments, presumably due to the different climatic requirements of coexisting color morphs.

• Klíčová slova
• adaptive polymorphism, color morphs, evolutionary dynamics, geographic variation, phenotypic diversity, thermal melanism,
• MeSH
• aklimatizace MeSH
• barva MeSH
• biologická evoluce MeSH
• brouci * genetika   MeSH
• nadmořská výška MeSH
• teplota MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The main purpose of the study was to explore the effects of carrying police equipment on spatiotemporal and kinetic gait parameters. Two-hundred and seventy-five healthy men and women attending police academy (32% women) were randomly recruited. Gait analysis without and with a police equipment load (≈3.5 kg) was analyzed using the Zebris pressure platform. Differences and effect sizes were calculated using a Student t-test and Wilcoxon test for dependent samples and Cohen's D statistics. In both men and women, carrying police equipment significantly increased the foot rotation (effect size 0.13-0.25), step width (0.13-0.33), step time (0.25), stride time (0.13-0.25) and peak plantar pressure beneath the forefoot (0.16-0.30), midfoot (0.15-0.32) and hindfoot (0.13-0.25) region of the foot. Significant reductions in the step length (0.12-0.25), stride length (0.14-0.23), cadence (0.15-0.28) and walking speed (0.20-0.22) were observed in both sexes. Although significant, the effect sizes were mostly trivial in men and small in women. Our study shows significant changes in the spatiotemporal and kinetic gait parameters when carrying police equipment for both men and women. Although the effect sizes are trivial to small, carrying police equipment of ≈3.5 kg may have a negative impact on gait characteristics in first-year police officers.

• Klíčová slova
• distribution, force, load, special population, walking,
• MeSH
• biomechanika MeSH
• chůze (způsob) * MeSH
• chůze * MeSH
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• noha (od hlezna dolů) MeSH
• policie * MeSH
• selhání zařízení MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Cellular senescence, induced by genotoxic or replication stress, is accompanied by defects in nuclear morphology and nuclear membrane-heterochromatin disruption. In this work, we analyzed cytological and molecular changes in the linker of nucleoskeleton and cytoskeleton (LINC) complex proteins in senescence triggered by γ-irradiation. We used human mammary carcinoma and osteosarcoma cell lines, both original and shRNA knockdown clones targeting lamin B receptor (LBR) and leading to LBR and lamin B (LB1) reduction. The expression status and integrity of LINC complex proteins (nesprin-1, SUN1, SUN2), lamin A/C, and emerin were analyzed by immunodetection using confocal microscopy and Western blot. The results show frequent mislocalization of these proteins from the nuclear membrane to cytoplasm and micronuclei and, in some cases, their fragmentation and amplification. The timing of these changes clearly preceded the onset of senescence. The LBR deficiency triggered neither senescence nor changes in the LINC protein distribution before irradiation. However, the cytological changes following irradiation were more pronounced in shRNA knockdown cells compared to original cell lines. We conclude that mislocalization of LINC complex proteins is a significant characteristic of cellular senescence phenotypes and may influence complex events at the nuclear membrane, including trafficking and heterochromatin attachment.

• Klíčová slova
• LINC complex proteins, SUN1/2, heterochromatin-nuclear membrane disconnection, lamin B receptor, nesprin-1, γ-irradiation,
• MeSH
• časoprostorová analýza MeSH
• jaderný obal metabolismus   MeSH
• lidé MeSH
• membránové proteiny metabolismus   MeSH
• receptor laminu B MeSH
• receptory cytoplazmatické a nukleární genetika   MeSH
• stárnutí buněk genetika   MeSH
• záření gama terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• membránové proteiny MeSH
• receptory cytoplazmatické a nukleární MeSH

Using pine needles as a bio-sampler of atmospheric contamination is a relatively cheap and easy method, particularly for remote sites. Therefore, pine needles have been used to monitor a range of semi-volatile contaminants in the air. In the present study, pine needles were used to monitor polychlorinated biphenyls (PCBs) in the air at sites with different land use types in Sweden (SW), Czech Republic (CZ), and Slovakia (SK). Spatiotemporal patterns in levels and congener profiles were investigated. Multivariate analysis was used to aid source identification. A comparison was also made between the profile of indicator PCBs (ind-PCBs-PCBs 28, 52, 101, 138, 153, and 180) in pine needles and those in active and passive air samplers. Concentrations in pine needles were 220-5100 ng kg(-1) (∑18PCBs - ind-PCBs and dioxin-like PCBs (dl-PCBs)) and 0.045-1.7 ng toxic equivalent (TEQ) kg(-1) (dry weight (dw)). Thermal sources (e.g., waste incineration) were identified as important sources of PCBs in pine needles. Comparison of profiles in pine needles to active and passive air samplers showed a lesser contribution of lower molecular weight PCBs 28 and 52, as well as a greater contribution of higher molecular weight PCBs (e.g., 180) in pine needles. The dissimilarities in congener profiles were attributed to faster degradation of lower chlorinated congeners from the leaf surface or metabolism by the plant.

• Klíčová slova
• Active and passive samplers, Atmospheric pollution, Bio-sampler, Europe, Pine needle, Polychlorinated biphenyls, Sources, Spatial and temporal distribution,
• MeSH
• borovice lesní chemie   metabolismus   MeSH
• dioxiny chemie   metabolismus   MeSH
• listy rostlin chemie   MeSH
• monitorování životního prostředí metody   MeSH
• polychlorované bifenyly chemie   metabolismus   MeSH
• polychlorované dibenzodioxiny chemie   metabolismus   MeSH
• spalování odpadů MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa MeSH
• Názvy látek
• dioxiny MeSH
• polychlorované bifenyly MeSH
• polychlorované dibenzodioxiny MeSH