Atmospheric carbon dioxide (CO2) has increased substantially since the industrial revolution began, and physiological responses to elevated atmospheric CO2 concentrations reportedly alter the biometry and wood structure of trees. Additionally, soil nutrient availability may play an important role in regulating these responses. Therefore, in this study, we grew 288 two-year-old saplings of sessile oak (Quercus petraea (Matt.) Liebl.) in lamellar glass domes for three years to evaluate the effects of CO2 concentrations and nutrient supply on above- and belowground biomass, wood density, and wood structure. Elevated CO2 increased above- and belowground biomass by 44.3% and 46.9%, respectively. However, under elevated CO2 treatment, sapling wood density was markedly lower (approximately 1.7%), and notably wider growth rings-and larger, more efficient conduits leading to increased hydraulic conductance-were observed. Moreover, despite the vessels being larger in saplings under elevated CO2, the vessels were significantly fewer (p = 0.023). No direct effects of nutrient supply were observed on biomass growth, wood density, or wood structure, except for a notable decrease in specific leaf area. These results suggest that, although fewer and larger conduits may render the xylem more vulnerable to embolism formation under drought conditions, the high growth rate in sessile oak saplings under elevated CO2 is supported by an efficient vascular system and may increase biomass production in this tree species. Nevertheless, the decreased mechanical strength, indicated by low density and xylem vulnerability to drought, may lead to earlier mortality, offsetting the positive effects of elevated CO2 levels in the future.
Článek prezentuje výsledky farmakodynamické studie nového gelu obsahujícího extrakt z Aloe vera a extrakt z dubové kůry v podmínkách destruktivního zánětlivého onemocnění parodontu. Farmakodynamika nového gelu byla studována následujícími metodami: antimikrobiální účinek – difuzní metodou v agarovém gelu (srovnávaný produkt – Metrogyl denta® gel); reparativní účinek – na modelu lineárních řezných ran (srovnávaný produkt – měsíčková mast); protizánětlivá aktivita – na modelu akutního zánětu vyvolaného karagenanem (srovnávaný produkt – 5% gel sodné soli diklofenaku). V rámci studie bylo zjištěno, že antimikrobiální aktivita nového gelu proti Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6633, Pseu-domonas aeruginosa ATCC 27853, Candida albicansNCTC 885-653, Escherichia faecalis ATCC 29212. Staphylococcus mutans ATCC 35668 byla mírně nižší ve srovnání s gelem Metrogyl denta®, který vykazuje silnou antimikrobiální aktivitu. Podle reparativního účinku na modelu lineárních řezných ran vykazoval nový gel vyšší účinek (o 24 %, p < 0.001) ve srovnání s přípravkem na bázi léčivého rostlinného materiálu měsíčkovou mastí. Za podmínek akutního zánětu vyvolaného karagenanem byla prokázána významná protizánětlivá aktivita nového gelu. Přípravek překonal gel sodné soli diklofanaku v prvních hodinách experimentu, což ukazuje na anti lipooxygenázovou aktivitu nového gelu. Zjištěná antimikrobiální, reparativní a protizánětlivá aktivita nového gelu obsahujícího extrakty z Aloe vera a dubové kůry potvrdila možnost jeho použití při léčbě destruktivních zánětlivých onemocnění parodontu.
The article presents the results of a pharmacodynamic study of a new gel containing an extract of Aloe vera and an extract of oak bark under the condition of destructive inflammatory periodontal diseases. Pharmacodynamics of the new gel was studied by the following methods: antimicrobial effect – by diffusion method in agar gel (compared product – Metrogyl denta® gel); reparative effect – on the model of linear cut wounds (compared product – Calendula ointment); anti-inflammatory activity – on the model of acute carrageenan-induced inflammation (compared product – Diclofenac natrium gel5%). It has been established that the antimicrobial activity of the new gel against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Bacillus subtilisATCC 6633, Pseudomonas aeruginosa ATCC 27853, Candida albicans NCTC 885-653, Escherichia faecalisATCC 29212, and Staphylococcus mutans ATCC 35668 is slightly lower in comparison with Metrogyl denta® gel exhibiting a powerful antimicrobial activity. According to the reparative effect on the model of linear cut wounds, the new gel exceeded the effectiveness (by 24%, p < 0.001) of the compared drug based on the medicinal plant material – Calendula ointment. A significant anti-inflammatory activity of the new gel has been revealed under the conditions of acute carrageenan inflammation. It exceeded the Diclofenac natrium gel in the first hours of the experiment, indicating an anti-lipoxygenase activity of the new gel. The established antimicrobial, reparative and anti-inflammatory activity of a new gel containing aloe vera and oak bark extracts confirmed its potential use in the treatment of destructive inflammatory periodontal diseases.
The objective of the study was to evaluate changes in microbial communities with the predicted arrival of new species to Mediterranean forests under projected intensification of water stress conditions. For that, litter from three Mediterranean forests dominated respectively by Quercus pubescens Willd., Quercus ilex L. and Pinus halepensis Mill. were collected, and placed to their 'home' forest but also to the two other forests under natural and amplified drought conditions (i.e. rainfall reduction of 30%). Quantitative PCR showed that overall, actinobacteria and total bacteria were more abundant in Q. pubescens and Q. ilex than in P. halepensis litter. However, the abundance of both groups was dependent on the forest sites: placement of allochthonous litter to Q. pubescens and P. halepensis forests (i.e. P. halepensis and Q. pubescens, respectively) increased bacterial and fungal abundances, while no effect was observed in Q. ilex forest. P. halepensis litter in Q. pubescens and Q. ilex forests significantly reduced actinobacteria (A/F) and total bacteria (B/F) to fungi ratios. The reduction of rainfall did not influence actinobacteria and bacteria but caused an increase of fungi. As a result, a reduction of A/F ratio is expected with the plant community change towards the dominance of spreading P. halepensis under amplified drought conditions.
- MeSH
- Bacteria klasifikace izolace a purifikace MeSH
- borovice mikrobiologie MeSH
- dub (rod) mikrobiologie MeSH
- houby klasifikace izolace a purifikace MeSH
- lesy MeSH
- listy rostlin mikrobiologie MeSH
- mikrobiota MeSH
- období sucha MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Nest architecture is a fundamental character shaping immune strategies of social insects. The arboreal ant Temnothorax unifasciatus nests in cavities such as oak galls where the entire colony lives in a unique small chamber. In these conditions, physiological and behavioural strategies likely prevail over compartmentalisation and are presumably tuned with colony size. We designed two experiments to study chemical and behavioural immune strategies against the entomopathogenic fungus Metarhizium anisopliae in colonies of different sizes. First, we compared spore germination and length of germinal tubes inside artificial nests, designed to impede the contact between the ants and the fungus, in colonies of different size. In the absence of direct contact, Temnothorax unifasciatus colonies inhibit fungal growth inside their nests, presumably through volatile compounds. The analysis revealed a positive correlation between fungistatic activity and colony size, indicating that workers of smaller colonies do not invest a higher per capita effort in producing such substances compared to larger colonies. Second, we performed a removal experiment of contaminated and non-contaminated items introduced inside the nests of colonies of different size. Small colonies challenged with contaminated fibres showed an increased removal of all the items (both contaminated and non-contaminated) compared to small colonies challenged with non-contaminated fibres only. Conversely, larger colonies moved items regardless of the presence of the spores inside the nest. Colony size qualitatively affected removal of waste items showing a pathogen elicited reaction in small colonies to optimise the reduced workforce, while the removal behaviour in larger colonies revealed to be expressed constitutively.
Forecasting the growth of tree species to future environmental changes requires a better understanding of its determinants. Tree growth is known to respond to global-change drivers such as climate change or atmospheric deposition, as well as to local land-use drivers such as forest management. Yet, large geographical scale studies examining interactive growth responses to multiple global-change drivers are relatively scarce and rarely consider management effects. Here, we assessed the interactive effects of three global-change drivers (temperature, precipitation and nitrogen deposition) on individual tree growth of three study species (Quercus robur/petraea, Fagus sylvatica and Fraxinus excelsior). We sampled trees along spatial environmental gradients across Europe and accounted for the effects of management for Quercus. We collected increment cores from 267 trees distributed over 151 plots in 19 forest regions and characterized their neighbouring environment to take into account potentially confounding factors such as tree size, competition, soil conditions and elevation. We demonstrate that growth responds interactively to global-change drivers, with species-specific sensitivities to the combined factors. Simultaneously high levels of precipitation and deposition benefited Fraxinus, but negatively affected Quercus' growth, highlighting species-specific interactive tree growth responses to combined drivers. For Fagus, a stronger growth response to higher temperatures was found when precipitation was also higher, illustrating the potential negative effects of drought stress under warming for this species. Furthermore, we show that past forest management can modulate the effects of changing temperatures on Quercus' growth; individuals in plots with a coppicing history showed stronger growth responses to higher temperatures. Overall, our findings highlight how tree growth can be interactively determined by global-change drivers, and how these growth responses might be modulated by past forest management. By showing future growth changes for scenarios of environmental change, we stress the importance of considering multiple drivers, including past management and their interactions, when predicting tree growth.
- MeSH
- buk (rod) růst a vývoj MeSH
- dub (rod) růst a vývoj MeSH
- Fraxinus růst a vývoj MeSH
- klimatické změny * MeSH
- koloběh dusíku MeSH
- lesy MeSH
- období sucha MeSH
- stromy růst a vývoj MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
The target of this study was to evaluate the effect of extract of the European mistletoe - Viscum album quercus L. on spermatozoa motility and viability in vitro. The CASA system was used to determine the spermatozoa motility parameters at different time intervals (0, 1, 2 and 3 h) and spermatozoa viability was determined in five different doses of Viscum album quercus L [10 (QA), 6.6 (QB), 3.3 (QC), 2.5 (QD) and 2 (QE) mg/ml]. Results in experimental groups detected a significant deterioration on rabbit spermatozoa after 1, 2 and 3 hours, compared to the control. The initial total spermatozoa motility showed increased value for all doses of Viscum album quercus in comparison to control. After in vitro culture a dose-dependent decrease (QA: reduction of 69.7 %, QB: reduction of 40.9 %) was found. For the progressive spermatozoa most significant decrease (86.8 % for QA vs. 48.5 % for QB) was detected compared to the control after 3 hours of culture. Spermatozoa viability (MTT test) was decreased in all experiment groups at the end of experiment, but the differences were not significant. Significant alterations of membrane integrity were found in groups with the highest Viscum album quercus concentration (QA, QB), but acrosome integrity showed no significant changes. Results suggest negative dose- and time-dependent effect of Viscum album quercus at higher doses on spermatozoa motility and viability parameters in vitro.
- MeSH
- časové faktory MeSH
- dub (rod) * MeSH
- králíci MeSH
- motilita spermií účinky léků fyziologie MeSH
- rostlinné extrakty izolace a purifikace farmakologie MeSH
- spermie účinky léků fyziologie MeSH
- viabilita buněk účinky léků fyziologie MeSH
- Viscum album * MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Due to the ability of soil bacteria to solubilize minerals, fix N2 and mobilize nutrients entrapped in the organic matter, their role in nutrient turnover and plant fitness is of high relevance in forest ecosystems. Although several authors have already studied the organic matter decomposing enzymes produced by soil and plant root-interacting bacteria, most of the works did not account for the activity of cell wall-attached enzymes. Therefore, the enzyme deployment strategy of three bacterial collections (genera Luteibacter, Pseudomonas and Arthrobacter) associated with Quercus spp. roots was investigated by exploring both cell-bound and freely-released hydrolytic enzymes. We also studied the potential of these bacterial collections to produce enzymes involved in the transformation of plant and fungal biomass. Remarkably, the cell-associated enzymes accounted for the vast majority of the total activity detected among Luteibacter strains, suggesting that they could have developed a strategy to maintain the decomposition products in their vicinity, and therefore to reduce the diffusional losses of the products. The spectrum of the enzymes synthesized and the titres of activity were diverse among the three bacterial genera. While cellulolytic and hemicellulolytic enzymes were rather common among Luteibacter and Pseudomonas strains and less detected in Arthrobacter collection, the activity of lipase was widespread among all the tested strains. Our results indicate that a large fraction of the extracellular enzymatic activity is due to cell wall-attached enzymes for some bacteria, and that Quercus spp. root bacteria could contribute at different levels to carbon (C), phosphorus (P) and nitrogen (N) cycles.
In the Mediterranean ecosystem, wildfires are very frequent and the predicted future with a probable increase of fires could drastically modify the vegetation scenarios. Vegetation fires are an important source of gases and primary emissions of fine carbonaceous particles in the atmosphere. In this paper, we present gaseous and particulate emissions data from the combustion of different plant tissues (needles/leaves, branches and needle/leaf litter), obtained from one conifer (Pinus halepensis) and one deciduous broadleaf tree (Quercus pubescens). Both species are commonly found throughout the Mediterranean area, often subject to wildfires. Experiments were carried out in a combustion chamber continuously sampling emissions throughout the different phases of a fire (pre-ignition, flaming and smoldering). We identified and quantified 83 volatile organic compounds including important carcinogens that can affect human health. CO and CO2 were the main gaseous species emitted, benzene and toluene were the dominant aromatic hydrocarbons, methyl-vinyl-ketone and methyl-ethyl-ketone were the most abundant measured oxygenated volatile organic compounds. CO2 and methane emissions peaked during the flaming phase, while the peak of CO emissions occurred during the smoldering phase. Overall, needle/leaf combustion released a greater amount of volatile organic compounds into the atmosphere than the combustion of branches and litter. There were few differences between emissions from the combustion of the two tree species, except for some compounds. The combustion of P. halepensis released a great amount of monoterpenes as α-pinene, β-pinene, p-cymene, sabinene, 3-carene, terpinolene and camphene that are not emitted from the combustion of Q. pubescens. The combustion of branches showed the longest duration of flaming and peak of temperature. Data presented appear crucial for modeling with the intent of understanding the loss of C during different phases of fire and how different typologies of biomass can affect wildfires and their speciation emissions profile.
- MeSH
- biomasa MeSH
- borovice chemie MeSH
- cévnaté rostliny chemie MeSH
- dub (rod) chemie MeSH
- látky znečišťující vzduch analýza MeSH
- monoterpeny analýza MeSH
- ničivé požáry * MeSH
- pevné částice analýza MeSH
- plyny analýza MeSH
- prach analýza MeSH
- stromy chemie MeSH
- těkavé organické sloučeniny analýza MeSH
- terpeny analýza MeSH
- Publikační typ
- časopisecké články MeSH
Rapid adaptation of insect species to environmental changes can be advantageous for their development. Forest cockchafer (Melolontha hippocastani) is herbivorous insect species with high food intake that has been widely studied within European conditions. It can cause huge economic and ecological losses especially in oak-dominated forest stands. Food preference of this species is mainly comprised of trees with a potential to accumulate manganese in their assimilation apparatus. In order to determine cockchafer's reactions to increased Mn concentration in its food, the adults were reared in laboratory conditions controlled for temperature, humidity, and light on a natural diet of oak (Quercus petraea) leaves. Food was contaminated by soaking in solutions of MnCl2·4H2O in concentrations from 0.5 to 10mgml-1. Food consumption, activity period of adults, quantity of eggs laid, body weights of individuals, as well as Mn concentrations in unconsumed food, excrement, and the bodies of cockchafers were determined to indicate how these change in reaction to food quality altered in terms of Mn content. The results showed that very high Mn content in the diet significantly influenced food consumption by M. hippocastani adults and thereby their development. This was in spite of the tendency of individuals to expel Mn through the faeces and incorporate it into undetermined parts of their bodies. Negative reactions of the experimental population were determined in treatments fed leaves with Mn concentration of 1800ppm and more. Our experiment proved that Mn can greatly influence the phytophagous cockchafer (decreased feeding time, food consumption, and fertility).
- MeSH
- brouci účinky léků růst a vývoj MeSH
- býložravci MeSH
- dieta MeSH
- dub (rod) chemie MeSH
- fertilita účinky léků MeSH
- krmivo pro zvířata analýza MeSH
- listy rostlin chemie MeSH
- mangan analýza farmakologie MeSH
- přijímání potravy účinky léků MeSH
- tělesná hmotnost účinky léků MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Root exudates comprise a large variety of compounds released by plants into the rhizosphere, including low-molecular-weight primary metabolites (particularly saccharides, amino acids and organic acids) and secondary metabolites (phenolics, flavonoids and terpenoids). Changes in exudate composition could have impacts on the plant itself, on other plants, on soil properties (e.g. amount of soil organic matter), and on soil organisms. The effects of drought on the composition of root exudates, however, have been rarely studied. We used an ecometabolomics approach to identify the compounds in the exudates of Quercus ilex (holm oak) under an experimental drought gradient and subsequent recovery. Increasing drought stress strongly affected the composition of the exudate metabolome. Plant exudates under drought consisted mainly of secondary metabolites (71% of total metabolites) associated with plant responses to drought stress, whereas the metabolite composition under recovery shifted towards a dominance of primary metabolites (81% of total metabolites). These results strongly suggested that roots exude the most abundant root metabolites. The exudates were changed irreversibly by the lack of water under extreme drought conditions, and the plants could not recover.
