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ABSTRACT: Effect of nitric oxide donor (sodium nitroprusside, SNP, 500 μM) or hydrogen peroxide scavenger (dithiothreitol, DTT, 500 μM) on cadmium (Cd) or copper (Cu) uptake (150 μM solutions) and toxicity using Scenedesmus quadricauda was studied. Combined treatments (Cd or Cu + DTT or SNP) usually ameliorated metal-induced toxicity at the level of pigments, proteins, and mineral nutrients in comparison with respective metal alone. Viability tests (MTT and TTC) showed the lowest values preferentially in Cu treatments, indicating higher toxicity in comparison with Cd. Cd showed low impact on amino acids while strong Cu-induced depletion was mitigated by DTT and SNP. Amount of ROS and NO showed the most pronounced responses in SNP variants being rather reciprocal than parallel and regulated ascorbate peroxidase activity. Blot gel analyses of hsp70 protein did not reveal extensive changes after given exposure period. Phenols were elevated by DTT alone while all Cu treatments revealed depletion. Total Cu content decreased while total Cd content increased in metal + SNP or metal + DTT. Subsequent experiment using lower Cd, SNP or DTT doses (10 and 100 μM) revealed concentration-dependent impact on Cd uptake. Overall, DTT was found to be more suitable for the amelioration of metal-induced toxicity.
Environmental Science and Pollution Research 02/2013; · 2.65 Impact Factor
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ABSTRACT: In the present work, the long-term effect (14days) of copper on the levels of intracellular and total copper accumulation,
growth, assimilation pigment composition, chlorophyll a fluorescence, soluble protein content and oxidative status (production of hydrogen peroxide and superoxide) in two algal
species (Scenedesmus quadricauda and Trebouxia erici) was assessed. Scenedesmus quadricauda is a free-living alga while Trebouxia erici is the photobiont of a lichen. The presence of copper negatively affected growth, assimilation pigments, chlorophyll a fluorescence, soluble protein content and oxidative status in both the algae. However, Scenedesmus was much more sensitive compared to Trebouxia.
KeywordsAlgae-Copper-Growth-Lichens-Photobionts-Toxicity
Plant Growth Regulation 05/2012; 63(1):81-88. · 1.60 Impact Factor
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ABSTRACT: Cadmium and copper uptake and its consequence for activity of selected enzymes of phenolic metabolism, phenolic acids accumulation,
quantity of mineral nutrients and stress-related parameters in Matricaria chamomilla plants exposed to 60μM and 120μM for 7days has been studied. Cu content in the above-ground biomass was ca. 10-fold lower
compared to Cd and amount of Cd in the methanol-soluble fraction was lower than in the water-soluble fraction. “Intra-root”
Cd represented 68% and 63% of total Cd content at 60μM and 120μM, but no difference was observed in Cu-exposed roots. Cu
excess had more pronounced effect on shikimate dehydrogenase, cinnamyl alcohol dehydrogenase, polyphenol oxidase and ascorbate
peroxidase activity mainly in the roots. Among eight detected benzoic acid derivatives and four cinnamic acid derivatives,
the latter were preferentially accumulated in response to Cd excess. Content of salicylic acid increased in all variants.
Amount of superoxide was elevated in both the rosettes (preferentially by Cu) and roots (preferentially by Cd). Accumulation
of Ca and Mg was not affected by excess of metals, while potassium decreased in both the rosettes and roots (Cu caused stronger
depletion). Amount of Fe increased in the roots in response to both metals (more expressively in Cu-treated ones). Present
study using other metabolic parameters (and supplementing our previous studies) has confirmed higher Cu toxicity for chamomile
plants, to support its strong pro-oxidant properties. These observations as complex metabolic responses are discussed.
Plant and Soil 04/2012; 320(1):231-242. · 2.73 Impact Factor
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ABSTRACT: The effect of nickel (Ni) excess on selected aspects of chamomile (Matricaria chamomilla L.) metabolism was studied. Water-soluble Ni represented 27%, 46%, and 47%, and the methanol-soluble fraction 54%, 70%, and
88% of total shoot Ni content after 10days of treatments with 3, 60, and 120μM Ni, respectively. “Intra-root” Ni content
represented 72% (3μM), 96% (60μM), and 78% (120μM) of total root Ni. Leaf rosettes treated with 120μM contained 137μg
Ni g−1 DW after 10days of treatment. The highest Ni concentration particularly affected the content of mineral nutrients (e.g.,
decrease of K and increase of Fe) and activity of selected antioxidative enzymes (increase of ascorbate peroxidase and guaiacol
peroxidase activities). Malondialdehyde accumulation was not influenced (measured in methanol extracts). Among 17 detected
free amino acids, accumulation of histidine, proline, methionine, and cysteine was most distinct in the leaf rosettes and/or
roots, indicating their involvement in Ni detoxification. Lower Ni toxicity in comparison to previously tested metals is also
discussed.
Water Air and Soil Pollution 04/2012; 202(1):199-209. · 1.63 Impact Factor
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ABSTRACT: This study was undertaken with the aim of investigating the effect of Cd2+ and Ni2+ containing solutions on selected physiological parameters (metal uptake, chlorophyll a fluorescence, assimilation pigment composition, thiobarbituric acid-reactive substance production, and ergosterol content)
in the lichens Peltigera rufescens and Cladina arbuscula subsp. mitis growing on historic copper mine-spoil heaps at Ľubietová-Podlipa, Slovakia. Physiological measurements did not confirm significantly
higher sensitivity to Cd and Ni of the cyanolichen P. rurescens compared to the green-algal lichen C. arbuscula subsp. mitis. Under natural conditions, C. arbuscula subsp. mitis is able to grow directly on copper mine heaps of Central Slovakia, while P. rufescens grows only on their margins. A crucial factor for this limited distribution of P. rufescens may be, at least in part, the higher intracellular accumulation of metals. Although lichen photobionts are generally regarded
as key elements of lichen sensitivity, further research is necessary to elucidate this point since the higher levels of intracellular
Cd and Ni do not allow to regard cyanobacterial photobionts of P. rufescens as more sensitive than the eukaryotic ones of C. arbuscula subsp. mitis.
Water Air and Soil Pollution 04/2012; 207(1):253-262. · 1.63 Impact Factor
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ABSTRACT: Peltigera rufescens (Weis) Humb. with a prokaryotic photobiont Nostoc sp. and Cladina arbuscula subsp. mitis (Sandst.) Ruoss with a eukaryotic photobiont Trebouxia sp. were studied to determine the copper sensitivity of lichens with different algal symbionts. Samples growing on historic
copper mine-spoil heaps at Ľubietová–Podlipa, Slovakia were assessed for physiological parameters, including total and intracellular
uptake of copper, assimilation pigmentation, activity of photosystem II, ergosterol levels, thiobarbituric acid reactive substances
and water-soluble protein content. Our results indicate that P. rufescens was more sensitive to copper exposure than C. arbuscula subsp. mitis.
Plant Growth Regulation 04/2012; 58(3):279-286. · 1.60 Impact Factor
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ABSTRACT: In this study we assessed the degree of copper (Cu) tolerance in two common lichen species (Cladonia furcata and Cladina arbuscula subsp. mitis) that grow on both uncontaminated substrata and the surface of waste heaps from abandoned old Cu-mines. Regardless of their locality, populations of these lichens contain identical strains of photobionts (Asterochloris clade A in C. arbuscula subsp. mitis and clade D in C. furcata). Therefore, it was expected that if there were differences in Cu toxicity or tolerance between populations, that the photobiont could not be a key element of Cu tolerance in these two lichen species. In laboratory experiments samples of both lichen species (from contaminated and control sites) were incubated in Cu solutions (500 μM) for 24 h. We attempted to determine whether Cu tolerance in these lichens was constitutive, or inducible form. Based on measurements of Cu accumulation, chlorophyll a integrity, chlorophyll a fluorescence, photosynthesis, respiration, measurements of the content of thiobarbituric acid reactive substances (TBARS), the content of soluble proteins, reactive oxygen species (ROS) and the amount of extracellular secondary metabolites of both lichens we found that there were no significant differences in the response of all selected populations of both lichen species to short-term exposure to these high levels of Cu. As a result, we conclude that Cu tolerance in these two lichen species is the constitutive rather than the inducible.
Chemosphere 06/2011; 85(1):106-13. · 3.21 Impact Factor
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ABSTRACT: Selected physiological responses of Tillandsia albida (Bromeliaceae) and two lichens (Hypogymnia physodes and Xanthoria parietina) exposed to simulated acid rain (AR) over 3 months were studied. Pigments were depressed in all species being affected the most in Tillandsia. Amounts of hydrogen peroxide and superoxide were elevated and soluble proteins decreased only in AR-exposed Hypogymnia. Free amino acids were slightly affected among species and only glutamate sharply decreased in AR-exposed Xanthoria. Slight increase in soluble phenols but decrease in flavonoids in almost all species suggests that the latter are not essential for tolerance to AR. Almost all phenolic acids in Tillandsia leaves decreased in response to AR and activities of selected enzymes (phenylalanine ammonia-lyase, polyphenol oxidase, ascorbate- and guaiacol-peroxidase) were enhanced by AR. In lichens, considerable increase in metabolites (physodalic acid, atranorin and parietin) in response to AR was found but amount of ergosterol was unchanged. Macronutrients (K, Ca, Mg) decreased more pronouncedly in comparison with micronutrients in all species. Xanthoria showed higher tolerance in comparison with Hypogymnia, suggesting that could be useful for long-term biomonitoring.
Ecotoxicology 03/2011; 20(2):348-57. · 2.36 Impact Factor
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ABSTRACT: This study aimed at investigating the cellular distribution of Hg in the lichens Cladonia arbuscula subsp. mitis and Peltigera rufescens treated with Hg²(+) and at testing if Hg treatment affects selected physiological parameters. In both species, increasing Hg accumulation under increasing Hg supply in the treatment solutions was found. P. rufescens showed a higher intracellular accumulation. Photosynthetic parameters were negatively affected in both species, as indicated by the decrease in photosynthetic pigments content, photosynthetic efficiency and chlorophyll integrity. Cell membranes of both species endured damage as indicated by the increase in the concentration of products of lipid peroxidation and decrease in ergosterol content. Nevertheless, differences between the two species were found, suggesting a differential sensitivity to Hg.
Chemosphere 02/2011; 82(7):1030-7. · 3.21 Impact Factor
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ABSTRACT: The aim of this study was to test in a short term laboratory experiment the accumulation and physiological effects of As in the epiphytic lichen Xanthoria parietina. Arsenic content in treated samples increased progressively with increasing concentration in treatment solutions. Treatment of X. parietina thalli with 0.1, 1, 10 ppm As solutions caused significant decrease of viability, measured as intensity of respiratory activity, and damages to cell membranes, assessed by increase of electric conductivity of rinsing water and lipid peroxidation products. Soluble proteins content decreased and H₂O₂ content increased already at the lowest As concentration tested (0.01 ppm). Photosynthetic efficiency, measured in terms of F(V)/F(M) ratio, decreased significantly only at the highest As concentration (10 ppm). It was concluded that As exposure causes physiological stress both on the mycobiont and the photobiont and that cell membrane damage, expressed in terms of electric conductivity of rinsing water, is the parameter most affected by As treatment.
Chemosphere 02/2011; 82(7):963-9. · 3.21 Impact Factor
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ABSTRACT: Tolerance of three Slovak populations of Silene vulgaris [from the localities "Harmanec" (total soil Cu 34.1 mg kg⁻¹), "Lubietová"; (total soil Cu 831.6 mg kg⁻¹) and "Špania dolina" (total soil Cu 1368.7 mg kg⁻¹) referred as SV1, SV2, and SV3, respectively] and Silene dioica (SD; from the locality "Špania dolina") exposed to 60 μM Cu for 7 days has been studied. Respective controls with 0.21 μM Cu were also cultured. SV3 and SD contained higher total shoot Cu than SV1. Methanol-soluble shoot Cu represented 60, 59, 59, and 55% from total shoot Cu and roots contained 16.7-, 20.4-, 9.9- and 28.9-fold more Cu than shoots in SV1, SV2, SV3, and SD, respectively. Soluble proteins were the least affected in SV3 and SD when Cu-exposed and control plants were compared. Root hydrogen peroxide and superoxide showed similar trend and were correlated with enhancement of ascorbate- and guaiacol-peroxidase activities. Malondialdehyde accumulation increased in SV1 and SV2. Phenylalanine ammonia-lyase activity and total soluble phenols were higher in SV3 Cu-exposed plants compared to SV1 and SV2. Shikimate dehydrogenase activity was enhanced in all Cu-exposed populations. Cinnamyl alcohol dehydrogenase activity and root lignin content were not affected and polyphenol oxidase activity was not detected. Within 14 detected free amino acids, majority of them decreased preferentially in the roots. Only serine increased in shoots and decreased in roots of all populations. Potassium content was not affected in SV3. Na, Ca, and Fe increased in roots of Cu-exposed plants of all populations, while Mg was the least affected and Zn increased in SV2 and SV3 shoots and roots. This study revealed the highest tolerance in population from the locality with the highest soil Cu content. Present findings as complex metabolic responses to Cu stress with special emphasis on phenolic metabolism are discussed.
Environmental Toxicology 07/2009; 25(6):581-92. · 2.41 Impact Factor
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ABSTRACT: The influence of increased copper and cadmium concentrations on membrane lipid peroxidation and photosynthetic characteristics of the lichen photobiont Trebouxia erici was assessed. Intracellular copper and cadmium uptake increased due to increased metal availability in the 5 mM HEPES buffer for 24 h. Assimilation pigments, chlorophyll a fluorescence, malondialdehyde (MDA) content and photosynthetic oxygen evolution rate (OER) were sensitive to the presence of redox-reactive metal Cu2+ in short-term experiments. Cd2+ decreased FV/FM values indicating damage to PSII and decrease of OER. However, assimilation pigments and MDA content were not altered significantly.
The Bryologist 01/2009; · 0.90 Impact Factor
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ABSTRACT: The effects of nitrogen deficiency on selected physiological attributes, phenylalanine ammonia-lyase (PAL, EC. 4.3.1.5) activity,
phenolic contents, peroxidase (EC. 1.11.1.7) and catalase (EC. 1.11.1.6) activities, lipid peroxidation status and H2O2 accumulation were studied in N-deficient Matricaria chamomilla (L.) over 12days. N deficiency enhanced root growth and inhibited shoot growth. Chlorophyll composition and F
v/F
m were not affected by N stress, but nitrogen and soluble proteins decreased in both the rosettes and the roots. PAL activity,
expressed per mg protein, was enhanced in N-deficient rosettes and tended to decrease by the end of the experiment, while
in the roots PAL activity was maintained. Total phenolic contents increased in both rosettes and roots. Peroxidase and catalase
activities in N-deficient rosettes tended to decrease by the end of the experiment, while in the roots they increased on the
12th day of deficiency. Furthermore, lipid peroxidation status increased in N-deficient roots on the 12th day, indicating
that antioxidative protection was insufficient to scavenge reactive oxygen species being generated. Surprisingly, H2O2 content was even lower in N-deficient roots by the end of the experiment, while in the leaves increased. This observation
in correlation to lipid peroxidation and H2O2 degradation is discussed. The importance of PAL activity and phenolic metabolites in combination with antioxidative enzymes
for plant protection against oxidative stress and the significance of PAL activity for the mobilization of N availability
in N-deficient tissue are also discussed in view of existing information.
Plant and Soil 07/2007; 297(1):255-265. · 2.73 Impact Factor
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ABSTRACT: Four-week-old chamomile (Matricaria chamomilla) plants were exposed for 72h to 0.01, 0.1 and 1mM phenylalanine (Phe) or tyrosine (Tyr). Phe at all concentrations significantly
increased phenylalanine ammonia-lyase (PAL) activity (by 30, 76 and 90%, respectively) as well as accumulation of coumarin-related
compounds (herniarin and its precursors (Z)- and (E)-2-β-D-glucopyranosyloxy-4-methoxycinnamic acids). Free Phe content increased significantly at the highest dose tested. Lower
Tyr concentrations (0.01 and 0.1mM) significantly increased PAL activity and increased free Tyr content, however free Phe
content decreased. This indicated that Tyr-mediated stimulation of PAL is coupled to Phe consumption. Notwithstanding, Tyr
had no effect on coumarin accumulation. Therefore we speculate that in chamomile a regulation/signalling mechanism could be
operating in the pathway leading to coumarin synthesis. The malondialdehyde accumulation, an usual marker of stress in plants,
was not significantly changed by amino acid supplements, suggesting that membrane damage is not the signal causing coumarin
accumulation. In parallel experiment we observed that neither lower (0.25×full strength), nor higher (3×full strength)
nitrogen concentration of nutrient solution compared to normal (1×full strength, 205mg Nl-1) solution used for Phe/Tyr supply affected herniarin and GMCAs accumulation. This indicates that Phe had stimulatory effect
on PAL activity and coumarin metabolism.
Plant Growth Regulation 04/2007; 52(1):9-15. · 1.60 Impact Factor
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ABSTRACT: Phenylalanine ammonia-lyase activity (PAL, EC 4.3.1.5), total phenolics, soluble proteins, malondialdehyde and metals accumulation
in four-week old chamomile (Matricaria chamomilla) plants cultivated in nutrient solution and exposed to low (3μM) and high (60 and 120μM) levels of cadmium (Cd) or copper
(Cu) for 7days were studied. High Cd concentrations had a stimulatory effect on PAL activity and soluble phenolics accumulation
while high Cu doses decreased soluble proteins in the leaf rosettes. In the roots, extreme stimulatory effects of 60 and 120μM
Cu were observed on PAL activity, phenolics and malondialdehyde accumulation, while protein content was reduced by these Cu
doses. Cd accumulation was higher in the leaf rosettes compared to copper, but the opposite was recorded in the roots. Taken
together, the stimulatory effect of Cu on phenolic metabolism was recorded, even though high malondialdehyde accumulation
may be an indication that phenolics was not sufficient to counteract reactive oxygen species formation thus leading to damage
of membrane integrity. In comparison to Cd, Cu had more noticeable effect on the parameters studied to support its strong
redox-active properties. These facts in correlation to antioxidative properties of phenolic metabolites are also discussed.
Water Air and Soil Pollution 01/2007; 185(1):185-193. · 1.63 Impact Factor
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ABSTRACT: The influence of low (3µM) and high (60 and 120µM) cadmium (Cd) concentrations were studied on selected aspects of metabolism in 4-week-old chamomile (Matricaria chamomilla L.) plants. After 10days’ exposure, dry mass accumulation and nitrogen content were not significantly altered under any of the levels of Cd. However, there was a significant decline in chlorophyll and water content in the leaves. Among coumarin-related compounds, herniarin was not affected by Cd, while its precursors (Z)- and (E)-2-β-d-glucopyranosyloxy-4-methoxycinnamic acids (GMCAs) increased significantly at all the levels of Cd tested. Cd did not have any effect on umbelliferone, a stress metabolite of chamomile. Lipid peroxidation was also not affected by even 120µM Cd. Cd accumulation was approximately seven- (60µM Cd treatment) to eleven- (120µM Cd treatment) fold higher in the roots than that in the leaves. At high concentrations, it stimulated potassium leakage from the roots, while at the lowest concentration it could stimulate potassium uptake. The results supported the hypothesis that metabolism was altered only slightly under high Cd stress, indicating that chamomile is tolerant to this metal. Preferential Cd accumulation in the roots indicated that chamomile could not be classified as a hyperaccumulator and, therefore, it is unsuitable for phytoremediation.
Plant Growth Regulation 10/2006; 50(2):239-247. · 1.60 Impact Factor
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ABSTRACT: Two lichen species (Peltigera rufescens and Cladina arbuscula subsp. mitis) and one moss species (Racomitrium lanuginosum) growing on a copper mine heaps (probably 200–300 yr old) in the village of Špania dolina (Slovak Republic) were assessed for selected physiological parameters, including composition of assimilation pigments, chlorophyll a fluorescence, soluble proteins and free amino acid content. The lichen C. arbuscula subsp. mitis was collected also at a control locality where total copper concentration in the soil was approximately 3% that of the waste heaps. Concentrations of Al, Co, Cu, Ni, Sb and Zn were highest in thalli of Peltigera, while the moss Racomitrium contained the highest content of Fe and Pb. Thalli of Cladina contained less metals than the cyanolichen Peltigera, and except for Zn metal concentrations in Cladina from the control locality were lower than in thalli of the same species from copper mine heaps. Regardless of the species or locality, the composition of assimilation pigments and chlorophyll a fluorescence showed that the tested lichens and moss were in good physiological condition and adapted to increased copper levels in the soil. There were significantly different amounts of total free amino acids in Peltigera, Cladina and Racomitrium from the Cu-polluted field. However, differences in amount of free amino acids in control, as well as Cu-polluted thalli of Cladina were less pronounced.
Chemosphere.
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ABSTRACT: Owing to the abundance of phenolic metabolites in plant tissue, their accumulation represents an important tool for stress protection. However, the regulation of phenolic metabolism is still poorly known. The regulatory role of reactive oxygen species (ROS) in the activity of phenylalanine ammonia-lyase (PAL) in nitrogen (N)-deficient chamomile roots treated for 24 h was studied using three ROS scavengers [dithiothreitol (DTT), salicylhydroxamic acid, and sodium benzoate]. Scavengers decreased the level of hydrogen peroxide and/or superoxide (and up-regulated ascorbate/guaiacol peroxidase and glutathione reductase), but, surprisingly, stimulated PAL activity. This up-regulation was correlated with increases in nitric oxide (NO) content, total soluble phenols, selected phenolic acids, and, partially, lignin (being expressed the most in DTT-exposed roots). We therefore tested the hypothesis that NO may be involved in these changes. Application of 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) decreased PAL activity and the accumulation of soluble phenols in all treatments. Exogenous H2O2 and NO also stimulated PAL activity and the accumulation of phenols. We conclude that NO, in addition to hydrogen peroxide, may regulate PAL activity during N deficiency. The anomalous effect of PTIO on NO content and possible mechanism of ROS scavenger-evoked NO increases in light of the current knowledge are also discussed.
Free Radical Biology and Medicine.
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ABSTRACT: Four-week old plants of chamomile (Matricaria chamomilla) cultivated in nutrient solution were exposed to copper (3, 60 and 120 μM) for 10 days. At 120 μM, Cu decreased dry mass production, water, chlorophyll and nitrogen content in both the leaf rosettes and roots. Five phenolic acids were detected in methanol extracts of the leaf rosettes (protocatechuic, p-hydroxybenzoic, vanillic, chlorogenic and salicylic acid) and six additional compounds (gentisic, syringic, caffeic, sinapic and o-/p-coumaric acid) were released after acid hydrolysis. Most of the 11 phenolic acids detected increased in 60 μM Cu but in the 120 μM treatment their contents were lower or not significantly different from the control. Among coumarin-related compounds, (Z)- and (E)-2-ß-d-glucopyranosyloxy-4-methoxycinnamic acids increased in 60 and 120 μM Cu while herniarin rose in the 3 and 60 μM Cu by the end of the experiment. The amounts of umbelliferone were not affected by any of the doses tested. These facts in relation to antioxidative properties of phenolic metabolites are also discussed. The malondialdehyde content of the leaf rosettes was not affected by exposure of plants to 120 μM Cu in a time-course experiment but in the roots a sharp increase was observed after 24 and 48 h of treatment. At 120 μM, Cu stimulated a 9-fold higher K+ loss than the 60 μM treatment while at the lowest concentration it stimulated potassium uptake. Cu accumulation in the roots was 3-, 49- and 71-fold higher than that in the leaf rosettes in the 3, 60, and 120 μM Cu treatments, respectively. Results suggest that 120 μM Cu dose is limiting for chamomile growth under the conditions of present research.
Environmental and Experimental Botany.
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ABSTRACT: Influence of nickel (Ni) excess on selected physiological aspects of Matricaria chamomilla metabolism after 10 days of presence was studied. Biomass, water content, assimilation pigments and lignin contents were not affected by any of the doses tested. High Ni doses elevated root-soluble proteins. The highest Ni concentration stimulated accumulation of soluble phenolics in both the rosettes and roots, and hydrogen peroxide in the roots. Malondialdehyde content was unaltered, but proline content increased more pronouncedly in the rosettes. Histidine was elevated in the roots, suggesting its involvement in Ni retention. Roots contained 3.4, 7.3 and 6.1 times more Ni than leaf rosettes with 3, 60 and 120 μM treatments, indicating that chamomile is a Ni excluder. Leaf rosettes accumulated 174.1 μg Ni g−1 DW at 120 μM treatment. The results suggest chamomile tolerance to Ni excess and its considerable accumulation in above-ground biomass (ca. 30% of whole plant Ni content).
Ecotoxicology and Environmental Safety.
