Willows (Salix spp.) are considered to be effective for the phytoremediation of trace elements from contaminated soils, but their efficiency is limited in heavily polluted soils because of poor growth. Liming can be a desirable measure to decrease the plant availability of elements, resulting in improved plant development. Notably, large root area and maximum soil penetration are basic parameters that improve the efficiency of phytoremediation. The impact of soil chemical properties on willow root anatomy and the distribution of trace elements below-ground have rarely been studied. The effect of liming on root parameters, biomass allocation and trace element distribution in non-harvestable (coarse roots, fine roots, stumps) and harvestable plant parts (twigs and leaves) of Salix × smithiana was assessed at the end of a 4-year pot experiment with two trace element-polluted soils that differed in terms of soil pH. Stump biomass predominated in weakly acidic soil. In neutral soil, the majority of biomass was located in fine roots and stumps; the difference from other plant parts was minor. Trace elements were the most concentrated in fine roots. Translocation to above-ground biomass increased as follows: Pb < As < Zn~Cd. In contrast to Cd and Zn, great differences in As and Pb mobility in plants were recorded after measurements of individual below-ground biomass (stumps < coarse roots < fine roots). Lime application decreased the concentrations of mobile Cd and Zn and related levels in plants, improved biomass production and root parameters and increased the removal of all trace elements in weakly acidic soil. None or minimum differences in the monitored parameters were recorded for dolomite treatments in both soils. The dose and source of liming had crucial effects on root anatomy. Growing willows in limed trace element-polluted soils is a suitable measure for combination of two remediation strategies, i.e. phytoextraction of Cd and Zn and assisted phytostabilization of As and Pb.

• MeSH
• biodegradace MeSH
• biomasa MeSH
• kořeny rostlin anatomie a histologie   účinky léků   MeSH
• látky znečišťující půdu analýza   metabolismus   MeSH
• oxidy chemie   MeSH
• půda chemie   MeSH
• Salix účinky léků   růst a vývoj   metabolismus   MeSH
• sloučeniny vápníku chemie   MeSH
• stopové prvky analýza   metabolismus   MeSH
• těžké kovy analýza   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

OBJECTIVES: Previous studies using oral administration of environmentally relevant doses of cyanobacterial biomass containing microcystins (MCs) induced only sub-lethal effects in experimental birds. Therefore, the objective of this study was to obtain data on avian high-dose toxicity of MCs and compute LD50, if possible, following the natural oral route of administration. DESIGN: Responses of birds to single high-dose exposure to MCs were evaluated in fourteen-day old Japanese quail males (Coturnix coturnix japonica) with average body weight of 50 g which were randomly divided into five groups. Birds from four experimental groups were administered 7.5 ml of cyanobacterial biomass suspension containing increasing MCs quantities of 2500, 5000, 10000, and 20000 µg/kg using oral gavage. Controls received an equal dose of drinking water instead of the test substance. Birds were observed for clinical signs of acute toxicity. Survivors were killed on day 5 to obtain body and liver weights. A five-grade semi-quantitative system for histopathological liver damage scoring was used to compare cyanobacterial-biomass-exposed birds against controls. RESULTS: No mortality occurred during the period of five days post exposure in both control and MCs-exposed groups and this high-dose experiment failed to provide data to compute the LD50. Nevertheless, marked sub-lethal effects were recognised in the damage of liver that included dose-dependent changes in the body/liver ratios and morphological changes ranging from mild vacuolar dystrophy to focal liver necroses in the highest exposure group. Hepatic lesions were mainly observed in the pericentral area of the liver. CONCLUSIONS: Though maximum cyanobacterial biomass dose rates that could be administered to birds of the size were used in the present experiment and more pronounced hepatic lesions than after exposure to environmentally relevant doses were observed, birds would probably have survived unless killed for histopathology on day 5 of exposure. These results provide support to previously reported data on sub-lethal effects following exposure to cyanobacterial biomass containing MCs in birds and mortality occurring only in birds under combined action with other stressors.

• MeSH
• bakteriální toxiny toxicita   MeSH
• biomasa MeSH
• Coturnix * MeSH
• hepatocyty účinky léků   patologie   MeSH
• karcinogeny toxicita   MeSH
• LD50 MeSH
• lékové postižení jater epidemiologie   patologie   MeSH
• mikrocystiny toxicita   MeSH
• mořské toxiny toxicita   MeSH
• náhodné rozdělení MeSH
• rizikové faktory MeSH
• sinice chemie   MeSH
• tělesná hmotnost MeSH
• velikost orgánu MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVES: The aim of the present study was to evaluate differences between juvenile and adult Japanese quails in responses to the exposure to cyanobacterial biomass in the diet. DESIGN: The OECD 205 Guideline on Avian Dietary Toxicity Test (1984) was employed in the experiment. A total of 75 freshly hatched chicks and 30 adults were exposed to cyanobacterial biomass for 15 days and blood sampled daily and on days 5, 10 and 15, respectively. Japanese quail chicks and adults received the same daily dose of approximately 224.4 ng microcystins per gram of body weight. Biochemical responses were compared against controls. RESULTS: No Japanese quail chicks and adults died during the acute 15-day-cyanobacterial-biomass exposure. Biochemical responses to the biomass in diet were first observed from day 5 post exposure to cyanobacterial biomass both in chicks and adults and there were age-related differences in the parameters changed. The responses of adult birds included an increase in lactate dehydrogenase, a drop in glucose and the total antioxidant capacity as well as a 15 to 20 % inhibition of acetylcholinesterase activity. Japanese quail chicks exposed to cyanobacterial biomass for the first 15 days after hatching reacted by having hypoproteinaemia, increased concentrations of triglycerides, uric acid and the total antioxidant capacity and a drop in high-density lipoprotein cholesterol in the blood. CONCLUSIONS: Chicks were not found to be more susceptible to the effects of biomass exposure. It seems that, due to their physiological preparation for the oxidative stress associated with hatching, Japanese quail chicks were even better able to cope with the cyanobacterial-biomass-induced oxidative stress than adults.

• MeSH
• acetylcholinesterasa krev   MeSH
• antioxidancia metabolismus   MeSH
• biomasa MeSH
• časové faktory MeSH
• Coturnix krev   růst a vývoj   metabolismus   MeSH
• dieta MeSH
• fyziologický stres fyziologie   MeSH
• HDL-cholesterol krev   MeSH
• hypoproteinemie krev   etiologie   metabolismus   MeSH
• krevní glukóza MeSH
• kyselina močová krev   MeSH
• L-laktátdehydrogenasa krev   MeSH
• náhodné rozdělení MeSH
• sinice MeSH
• stárnutí MeSH
• triglyceridy krev   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

During the growing season, trees allocate photoassimilates to increase their aboveground woody biomass in the stem (ABIstem). This 'carbon allocation' to structural growth is a dynamic process influenced by internal and external (e.g., climatic) drivers. While radial variability in wood formation and its resulting structure have been intensively studied, their variability along tree stems and subsequent impacts on ABIstem remain poorly understood. We collected wood cores from mature trees within a fixed plot in a well-studied temperate Fagus sylvatica L. forest. For a subset of trees, we performed regular interval sampling along the stem to elucidate axial variability in ring width (RW) and wood density (ρ), and the resulting effects on tree- and plot-level ABIstem. Moreover, we measured wood anatomical traits to understand the anatomical basis of ρ and the coupling between changes in RW and ρ during drought. We found no significant axial variability in ρ because an increase in the vessel-to-fiber ratio with smaller RW compensated for vessel tapering towards the apex. By contrast, temporal variability in RW varied significantly along the stem axis, depending on the growing conditions. Drought caused a more severe growth decrease, and wetter summers caused a disproportionate growth increase at the stem base compared with the top. Discarding this axial variability resulted in a significant overestimation of tree-level ABIstem in wetter and cooler summers, but this bias was reduced to ~2% when scaling ABIstem to the plot level. These results suggest that F. sylvatica prioritizes structural carbon sinks close to the canopy when conditions are unfavorable. The different axial variability in RW and ρ thereby indicates some independence of the processes that drive volume growth and wood structure along the stem. This refines our knowledge of carbon allocation dynamics in temperate diffuse-porous species and contributes to reducing uncertainties in determining forest carbon fixation.

• MeSH
• biomasa MeSH
• buk (rod) * MeSH
• dřevo MeSH
• lesy MeSH
• stromy MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVES: The present study was aimed at evaluation of the response of Japanese quails to cyanobacterial biomass administered in feed using biochemical profiles and parameters of reproduction. DESIGN: Effects of cyanobacterial biomass were studied according to the OECD 206 Guideline on Avian Reproduction Toxicity. A total of 16 control and 16 experimental pairs (32 males and 32 females) were analyzed. The chronic exposure of parent birds lasted eight weeks with the daily sum of 61.62 microg MCs including 26.54 microg MC-RR, 7.62 microg MC-YR and 27.39 microg MC-LR. RESULTS: There was no mortality both in control and cyanobacterial-biomass-exposed adults during the present study. Nor did the birds show any clinical signs of intoxication. Lactate dehydrogenase activity was increased about three-fold in exposed birds. No other biochemical parameters were showing significant differences. A total of 824 and 821 eggs were laid by control and exposed birds, respectively, during the eight-week study period. Eggs laid by cyanobacterial-biomass-exposed hens had lower weight than in controls (11.99+/-1.13g and 12.40+/-1.27g, respectively; p<0.01). Egg viability, hatchability, and the effect of hatching in control and experimental birds were 79.6+/-9.3 and 86.8+/-8.2% (p<0.05), 83.2+/-12.6 and 90.1+/-9.3%, and 65.2+/-17.7 and 77.7+/-15.2% (p<0.05), respectively. There was also a statistically significant difference in the number of 14-day old survivors per hen per day in control and experimental birds (0.38+/-0.02 and 0.43+/-0.01 %, respectively). CONCLUSION: The lower weight of eggs produced by exposed parental hens was not reflected in their biological quality. On the contrary, reproductive parameters in cyanobacterial-biomass-exposed birds were better than in the control group. It might be hypothesized that compounds of hormonal activity could be present in the complex cyanobacterial biomass. However, further research into this issue is necessary.

• MeSH
• časové faktory MeSH
• Coturnix krev   fyziologie   MeSH
• dieta MeSH
• L-laktátdehydrogenasa krev   MeSH
• náhodné rozdělení MeSH
• ovum fyziologie   MeSH
• rozmnožování fyziologie   MeSH
• sinice MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVES: The objective of this study was to examine the hypothesis that a combination of cyanobacterial biomass containing microcystins, acetylcholinesterase inhibitor and anticoagulant can enhance avian toxic effects produced by single exposures only. METHODS: A total of 48 two-month-old Japanese quails (Coturnix coturnix japonica) with average body weight of 160 g were randomly divided into 8 experimental groups of six birds and sex ratio of 1:1. Experimental groups of control Japanese quails (C) and birds exposed to single and combined sub-lethal doses of paraoxon (P), bromadiolone (B), and microcystins in cyanobacterial biomass (M) included: C, P, P+B, B, B+M, P+M, M, and P+B+M. During the 10-day exposure birds in the respective groups received biomass containing 61.62 µg microcystins daily (i.e. 26.54 µg MC-RR, 7.62 µg MC-YR and 27.39 µg MC-LR), two 250 μg/kg doses of paraoxon, and two 500 mg/kg doses of bromadiolone. Group responses were compared using standard plasma biochemistry and antioxidant/oxidative stress parameters in tissues. RESULTS: While single and double combinations of toxicants induced responses in individual biochemical parameters measured and evaluated using univariate statistical analysis, those in the triple exposure were most extensive. The principal component analysis of antioxidant/oxidative stress parameters (glutathione reductase, lipid peroxidation, and ferric reducing antioxidant power) in tissues (liver, kidney, heart, brain, lungs, gonads, and pectoralis major muscle) clearly separated the triple group (P+B+M) from all single and double exposure groups and the control and indicated thus marked joint effects in the overall pattern of antioxidant/oxidative stress responses of this group. The separation was driven by the modification of the ferric reducing antioxidant power levels in heart and brain and the cardiac lipid peroxidation level, in particular. CONCLUSIONS: This experiment contributes to the understanding of the pathogenic mechanisms of combined sub-lethal exposure to natural toxins and agrochemicals and may be used for risk assessment of environmental pollution in birds.

• MeSH
• 4-hydroxykumariny toxicita   MeSH
• antikoagulancia toxicita   MeSH
• biomasa MeSH
• cholinesterasové inhibitory toxicita   MeSH
• Coturnix * MeSH
• játra účinky léků   MeSH
• karcinogeny toxicita   MeSH
• kosterní svaly účinky léků   MeSH
• ledviny účinky léků   MeSH
• mikrocystiny toxicita   MeSH
• mozek účinky léků   MeSH
• náhodné rozdělení MeSH
• paraoxon toxicita   MeSH
• plíce účinky léků   MeSH
• rizikové faktory MeSH
• sinice chemie   MeSH
• srdce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Quantification of carbon (C) fluxes in mycorrhizal plants is one of the important yet little explored tasks of mycorrhizal physiology and ecology. (13)CO2 pulse-chase labelling experiments are increasingly being used to track the fate of C in these plant-microbial symbioses. Nevertheless, continuous monitoring of both the below- and aboveground CO2 emissions remains a challenge, although it is necessary to establish the full C budget of mycorrhizal plants. Here, a novel CO2 collection system is presented which allows assessment of gaseous CO2 emissions (including isotopic composition of their C) from both belowground and shoot compartments. This system then is used to quantify the allocation of recently fixed C in mycorrhizal versus nonmycorrhizal Medicago truncatula plants with comparable biomass and mineral nutrition. Using this system, we confirmed substantially greater belowground C drain in mycorrhizal versus nonmycorrhizal plants, with the belowground CO2 emissions showing large variation because of fluctuating environmental conditions in the glasshouse. Based on the assembled (13)C budget, the C allocation to the mycorrhizal fungus was between 2.3% (increased (13)C allocation to mycorrhizal substrate) and 2.9% (reduction of (13)C allocation to mycorrhizal shoots) of the plant gross photosynthetic production. Although the C allocation to shoot respiration (measured during one night only) did not differ between the mycorrhizal and nonmycorrhizal plants under our experimental conditions, it presented a substantial part (∼10%) of the plant C budget, comparable to the amount of CO2 released belowground. These results advocate quantification of both above- and belowground CO2 emissions in future studies.

• MeSH
• fotosyntéza fyziologie   MeSH
• Glomeromycota fyziologie   MeSH
• kořeny rostlin metabolismus   MeSH
• Medicago truncatula metabolismus   mikrobiologie   MeSH
• mykorhiza metabolismus   MeSH
• oxid uhličitý chemie   metabolismus   MeSH
• uhlík metabolismus   MeSH
• výhonky rostlin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

We studied cell properties including carbon allocation dynamics in the globally abundant and important cyanobacterium Prochlorococcus marinus strain PCC 9511 grown at three different growth rates in nitrogen-limited continuous cultures. With increasing nitrogen limitation, cellular divinyl chlorophyll a and the functional absorption cross section of Photosystem II decreased, although maximal photosynthetic efficiency of PSII remained unaltered across all N-limited growth rates. Chl-specific gross and net carbon primary production were also invariant with nutrient-limited growth rate, but only 20% of Chl-specific gross carbon primary production was retained in the biomass across all growth rates. In nitrogen-replete cells, 60% of the assimilated carbon was incorporated into the protein pool while only 30% was incorporated into carbohydrates. As N limitation increased, new carbon became evenly distributed between these two pools. While many of these physiological traits are similar to those measured in other algae, there are also distinct differences, particularly the lower overall efficiency of carbon utilization. The latter provides new information needed for understanding and estimating primary production, particularly in the nutrient-limited tropical oceans where P. marinus dominates phytoplankton community composition.

• MeSH
• dusík metabolismus   MeSH
• Prochlorococcus metabolismus   MeSH
• sinice metabolismus   MeSH
• uhlík metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

The assimilation of N-NO3- requires more energy than that of N-NH4+ . This becomes relevant when energy is limiting and may impinge differently on cell energy budget depending on depth, time of the day and season. We hypothesize that N-limited and energy-limited cells of the oceanic cyanobacterium Synechococcus sp. differ in their response to the N source with respect to growth, elemental stoichiometry and carbon allocation. Under N limitation, cells retained almost absolute homeostasis of elemental and organic composition, and the use of NH4+ did not stimulate growth. When energy was limiting, however, Synechococcus grew faster in NH4+ than in NO3- and had higher C (20%), N (38%) and S (30%) cell quotas. Furthermore, more C was allocated to protein, whereas the carbohydrate and lipid pool size did not change appreciably. Energy limitation also led to a higher photosynthetic rate relative to N limitation. We interpret these results as an indication that, under energy limitation, the use of the least expensive N source allowed a spillover of the energy saved from N assimilation to the assimilation of other nutrients. The change in elemental stoichiometry influenced C allocation, inducing an increase in cell protein, which resulted in a stimulation of photosynthesis and growth.

• MeSH
• adenosintrifosfát metabolismus   MeSH
• amoniové sloučeniny farmakologie   MeSH
• bakteriální proteiny metabolismus   MeSH
• biomasa MeSH
• dusičnany farmakologie   MeSH
• dusík metabolismus   MeSH
• energetický metabolismus * účinky léků   MeSH
• fosfor metabolismus   MeSH
• fotosyntéza účinky léků   MeSH
• kyslík metabolismus   MeSH
• lipidy analýza   MeSH
• sacharidy analýza   MeSH
• síra metabolismus   MeSH
• Synechococcus cytologie   účinky léků   růst a vývoj   metabolismus   MeSH
• uhlík metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

Membrane phospholipids, including phosphatidylcholine (PC) and phosphatidylethanolamine (PE), consist of distinct fatty acids occupying the sn-1 and sn-2 positions, reflecting the highly regulated nature of lipid biosynthesis. However, little is known about the influence of dietary lipids on the positional nature of fatty acids in tissues, including the enrichment of omega-3 polyunsaturated fatty acid (PUFA) in chicken egg yolk phospholipids. This study was undertaken to characterize the PC and PE species in egg lipids derived from Lohmann hens (n=10/treatment) randomly allocated to either a control (no supplementation), a flaxseed oil (FO) or a marine algal oil (MA) diet. Each of the FO or MA diets supplied three levels of total omega-3 PUFA (0.20, 0.40 and 0.60% of diet) that were provided for 6 weeks. A combination of multiplexed mass spectrometry (MS) experiments are used to determine total, isobaric, and position molecules for PC and PE in egg yolk. The distribution of phospholipids in the yolk was predominantly PC over PE (~72 vs. 23%, respectively) across treatments. The longer chain PUFA existed in the sn-2 position in the PC and PE. Although docosahexaenoic acid (22:6) formed isomers with fatty acids 16:0, 18:0 and 18:1; it was preferentially enriched in the egg in combination with 16:0 with both the FO and MA-fed groups in both lipid pools. All 22:6-containing isomers were enriched by ~2-fold more (P < 0.0001) with MA than FO, however, all isomers exhibited a plateau with the FO-fed group. In addition, the MS analyses of PCs revealed several isobaric species containing eicosapentaenoic acid (EPA, 20:5), however, in the PE, EPA formed only one isomer (i.e. in combination with 16:0). These results may assist to elucidate potential aspects regulating the limited enrichment of omega-3 PUFA, particularly EPA and docosahexaenoic acid (22:6) in chicken eggs.

• MeSH
• biomasa * MeSH
• fosfatidylcholiny metabolismus   MeSH
• fosfatidylethanolaminy metabolismus   MeSH
• krmivo pro zvířata * MeSH
• kur domácí metabolismus   MeSH
• kyseliny mastné omega-3 farmakologie   MeSH
• lipidomika MeSH
• lněný olej farmakologie   MeSH
• vaječný žloutek metabolismus   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH