Phenolic Compounds and Organic Acid Composition of Syringa vulgaris L. Flowers and Infusions.

The study aimed to determine the content of phenolic compounds (phenolic acids and flavonoids) and organic acids in dried flowers and water infusions of non-oxidised and oxidised flowers from four lilac cultivars. The diversity in the total phenolic and flavonoid content was in the flowers (18.35-67.14 and 2.03-2.65 mg g-1 DW, respectively) and infusions (14.72-47.78 and 0.20-1.84 mg per 100 mL infusion, respectively) depending the flower colour and form (oxidised and non-oxidised). Phenolic compounds and organic acids were susceptible to oxidation. Compared to infusions, flowers had more phenolic compounds and organic acids. The highest content of most phenolic compounds was confirmed for non-oxidised purple flowers (up to 7825.9 µg g-1 DW for chlorogenic acid) while in infusions for non-oxidised white flowers (up to 667.1 µg per 100 mL infusions for vanillic acid). The phenolic profile of the infusions was less diverse than that of flowers. The scavenging ability ranged from 52 to 87%. The highest organic acid content in flowers was for oxidised blue and purple flowers (2528.1 and 2479.0 µg g-1 DW, respectively) while in infusions the highest organic acid content was for oxidised purple flowers (550.1 µg per 100 mL infusions).

Trees and shrubs from a post-industrial area high in calcium and trace elements: the potential of dendroremediation.

NOVELTY STATEMENT: That is probably the first study to date of trees and shrubs differing in age and growing on post-industrial soil contaminated with calcium (Ca) and selected toxic metals/metalloids. The obtained results show that an alkaline reaction (less than 9) of soil and an unusually high Ca concentration may help the studied tree species to adapt/survive in unfavorable habitat conditions (high concentration of toxic elements). The efficiency of phytoextraction of toxic elements was so high that, especially for forest animals (roe-deer) that consume, e.g., willow shoots, it could pose a serious threat to health and life, both for them and potentially for humans.

The Content of Phenolic Compounds and Organic Acids in Two Tagetes patula Cultivars Flowers and Its Dependence on Light Colour and Substrate.

The main focus of the study was to determine the content of phenolic acids, flavonoids, and organic acids in the flowers of Tagetes patula 'Petite Gold' and 'Petite Orange'. The growth of the plants was assessed depending on the cultivation conditions. The above plants were illuminated with white light, whereas the 'Petite Gold' ones with white light enhanced with blue or red light. Both cultivars grew in a two-level-mineral compounds organic substrate. The research showed that the French marigold flowers were rich in phenolic compounds and organic acids. The 'Petite Gold' flowers had more bioactive compounds compared with the 'Petite Orange' flowers. Three flavonoids, 10 phenolic acids and seven organic acids were found in the 'Petite Gold' flowers. The artificial lighting used during the cultivation of the plants showed diversified influence on the content of organic compounds in their flowers. The measurements of the plants' morphological traits and the number of inflorescences showed that illumination with red light resulted in a better effect. Large plants with numerous inflorescences grew in the substrate with a lower content of nutrients.

Biofortification of Three Cultivated Mushroom Species with Three Iron Salts-Potential for a New Iron-Rich Superfood.

Mushrooms fortified with iron (Fe) can offer a promising alternative to counter the worldwide deficiency problem. However, the factors that may influence the efficiency of fortification have not yet been fully investigated. The aim of this study was to compare the effects of three Fe forms (FeCl3 6H2O, FeSO4 7H2O, or FeHBED) in three concentrations (5, 10, or 50 mM) for three mushroom species (Pleurotus eryngii, P. ostreatus, or Pholiota nameko) on their chemical composition, phenolic compounds, and organic acid production. The most effective metal accumulation of all the investigated species was for the 50 mM addition. FeCl3 6H2O was the most favorable additive for P. eryngii and P. nameko (up to 145 and 185% Fe more than in the control, respectively) and FeHBED for P. ostreatus (up to 108% Fe more than in control). Additionally, P. nameko showed the highest Fe accumulation among studied species (89.2 ± 7.51 mg kg-1 DW). The creation of phenolic acids was generally inhibited by Fe salt supplementation. However, an increasing effect on phenolic acid concentration was observed for P. ostreatus cultivated at 5 mM FeCl3 6H2O and for P. eryngii cultivated at 5 mM FeCl3 6H2O and 5 mM FeSO4 7H2O. In the case of organic acids, a similar situation was observed. For P. ostreatus, FeSO4 7H2O and FeHBED salts increased the formation of the determined organic acids in fruiting bodies. P. eryngii and P. nameko were characterized by a much lower content of organic acids in the systems supplemented with Fe. Based on the obtained results, we recommend starting fortification by preliminarily indicating which form of the element is preferred for the species of interest for supplementation. It also seems that using an additive concentration of 50 mM or higher is most effective.

Content of Phenolic Compounds and Organic Acids in the Flowers of Selected Tulipa gesneriana Cultivars.

The study focused on the determination of phenolic acids, flavonoids and organic acids in five tulip cultivars 'Barcelona', 'Columbus', 'Strong Gold', 'Super Parrot' and 'Tropicana'. The cultivars grown in field and in a greenhouse were exposed after cutting to different times of storage (0, 3 and 6 days). The phenolic profile contained 4-hydroxybenzoic, 2,5-dihydroxybenzoic, gallic, vanillic, syringic, salicylic, protocatechuic, trans-cinnamic, p-coumaric, caffeic, ferulic, chlorogenic and sinapic acids, as well as quercetin, rutin, luteonin, catechin and vitexin. The mean phenolic acid content was in the following order: 'Columbus' and 'Tropicana' > 'Barcelona' > 'Strong Gold' > 'Super Parrot', while the levels of flavonoids were as follows: 'Strong Gold' > 'Barcelona' > 'Tropicana' > 'Columbus' > 'Super Parrot'. The highest content of phenolic acids was confirmed for Columbus and Tropicana, while the lowest was for Super Parrot. However total phenolic content was very similar, observed between the place of cultivation, time of storage and cultivars. Malonic, succinic, acetic and citric acids were the major organic acid components in tulip petals. More organic acids (except malonic) were accumulated in tulip petals from fields than those from the greenhouse, while changes during storage were strictly correlated with cultivars.

The effect of drying temperature on bioactive compounds and antioxidant activity of Leccinum scabrum (Bull.) Gray and Hericium erinaceus (Bull.) Pers.

In the study the effect of drying temperature on phenolic and organic acid content, total phenolic content, ergosterol content, antioxidant activity and content of 40 elements in fruiting bodies of Leccinum scabrum and Hericium erinaceus was estimated. The analysis was performed for fresh fruiting bodies and those dried at 20, 40 and 70 °C. Drying resulted in changes in the profile of phenolic and organic acids. Drying generally resulted in losses of the content of total phenolics, ergosterol and antioxidant activity in both species. However, a reduction and an increase of phenolic acids and organic acids were observed. The greatest reduction of the compounds was generally observed at 70 °C. The greatest losses concerned organic acids (some single components and total) (even more than 90% of some compounds). The inhibition of free radicals decreased in the following order: fresh samples > air-dried samples > samples dried at 40 °C > samples dried at 70 °C. The drying temperature affected only selected element contents in fruiting bodies.

The importance of substrate compaction and chemical composition in the phytoextraction of elements by Pinus sylvestris L.

Trees of Scots pine (Pinus sylvestris L.) are known for their effective phytoextraction capabilities. The results obtained in this study point to the significant role of substrate composition and chemical characteristics in the phytoextraction potential of this species. A multi-elemental (53 elements) analysis of pines from unpolluted (soil) and polluted (post-flotation tailings) sites was performed using inductively coupled plasma optical emission spectrometry. The analyzed flotation tailings were characterized by alkaline pH (7.19 ± 0.06) and significantly higher conductivity (277.7 ± 2.9 µS cm-1) than the soil (pH = 5.11 ± 0.09; 81.3 ± 4.9 µS cm-1). The two substrates also differed with respect to the contribution of the clay fraction (0% in the unpolluted and 8% in the polluted substrate). The specimens of P. sylvestris growing on flotation tailings had significantly smaller height (381 ± 58 cm) and total aboveground biomass (4.78 ± 0.66 kg) than the trees growing in soil (699 ± 80 cm and 10.24 ± 2.10 kg). The biomass of the trunk, twigs and branches, and needles of the trees from polluted sites was between 40.0% and 48.7% of the biomass of the same organs of the control trees. Generally, the organs (trunk, twigs and branches, needles) of the P. sylvestris specimens from polluted sites had significantly higher concentrations of Au, Al, Ba, Cd, Co, La, Lu, Ni, Pd, Sc, Zn, and lower concentrations of B, Bi, Ca, Ce, Er, In, K, Mg, Na, Nd, P, Pr, Re, Se, Sr, Te than in the control plants, these metals being accumulated effectively in the whole of the aboveground biomass (BCF>1). Although the concentration of the majority of elements was significantly higher in the flotation tailings, significantly higher concentrations of these elements were observed in the tree organs from unpolluted sites, which points to the important role of substrate characteristics in the phytoextraction efficiency of P. sylvestris.

Cultivation of Agaricus bisporus enriched with selenium, zinc and copper.

BACKGROUND: Agaricus bisporus (white button mushroom) is an important culinary and medicinal species of worldwide importance. The present study investigated for the first time whether it may be grown on substrates supplemented with Se alone or in combination with Cu and/or Zn (0.1-0.8 mmol L-1 ) to produce fruiting bodies of increased nutritional value. RESULTS: As found, substrate supplementation did not affect yielded biomass up to 0.6 mmol L-1 element concentrations regardless of the cultivation model. At 0.8 mmol L-1 Se + Cu and Se + Zn supplementation biomass comparable with controls still developed. The accumulation of trace elements in the fruiting bodies generally increased over the concentration gradient reaching its maximum at 0.6 mmol L-1 (for Se + Zn and Se + Cu + Zn) and 0.8 mmol L-1 (for Se and Se + Cu). The organic Se constituted the greatest share in total Se quota. As calculated, each 10 g of dried fruiting bodies of A. bisporus obtained from 0.6 or 0.8 mmol L-1 supplementation would represent 342-469% of the Recommended Daily Allowance (RDA) for Se, 43.4-48.5% for Cu and 5.2-5.8% for Zn. CONCLUSION: Considering inexpensive methods of A. bisporus cultivation, global popularity and use of this mushroom, its biofortification with Se, Cu and Zn could have a practical application in deficiency prevention and assisted treatment. © 2016 Society of Chemical Industry.

The relationship between metal composition, phenolic acid and flavonoid content in Imleria badia from non-polluted and polluted areas.

The aim of this study was to determine the elemental composition, phenolic content and composition and antioxidant properties of Imleria badia (Fr.) Vizzini (former names Boletus badius (Fr.) Fr., and Xerocomus badius (Fr.) E.-J. Gilbert) fruiting bodies collected from sites with different levels of pollution. Imleria badia was relatively tolerant to soil contamination with toxic elements and was able to grow in As, Cd, Hg and Pb concentrations exceeding 15, 2.9, 0.4 and 77 mg kg-1, respectively. The concentration of elements in soil was reflected in the element content in I. badia. The fruiting bodies from polluted sites exhibited significantly higher content of all the analyzed elements. Among 21 individual phenolic compounds only protocatechiuc and caffeic acids, and quercetin were determined in fruiting bodies of I. badia. The differences between the concentration of the quantified phenolic compounds and the total flavonoid content in fruiting bodies of I. badia from unpolluted and polluted sites were not significant. However, the greatest total phenolic content was found in fruiting bodies from the polluted areas. The antioxidative capacity of mushrooms collected from heavily polluted sites was lower than those growing in unpolluted areas. The concentrations of some metals in soil and fruiting soil were positively correlated with phenolic content and IC50.

Multi-elemental analysis of Lentinula edodes mushrooms available in trade.

The present study investigated the content of 62 elements in the fruiting bodies of Lentinula edodes (Shiitake mushroom) cultivated commercially in Poland on various substrates from 2007-2015. The general mean content (mg kg-1 dry weight (DW)) of the studied elements ranked in the following order: K (26,335) > P (11,015) > Mg (2,284) > Ca (607) > Na (131) > Zn (112) > Fe (69) > Mn (33) > B (32) > Rb (17) > Cu (14.5) > Al (11.2) > Te (2.9) > As (1.80) > Cd (1.76) > Ag (1.73) > Nd (1.70) > Sr (1.46) > Se (1.41) > U (1.11) > Pt (0.90) > Ce (0.80) > Ba (0.61) > Co (0.59) > Tl (0.58) > Er (0.50) > Pb (0.42) > Li (0.40) > Pr (0.39) > Ir (0.37) > In (0.35) > Mo (0.31) > Cr (0.29) > Ni (0.28) > Sb (0.26) > Re (0.24) > Ti (0.19) > Bi (0.18) > Th (0.12) > La (0.10) = Pd (0.10) > Os (0.09) = Zr (0.09) > Rh (0.08) > Ho (0.07) > Ru (0.06) > Sm (0.04) = Eu (0.04) = Tm (0.04) > Gd (0.03) > Sc (0.02) = Y (0.02) > Lu (0.01) = Yb (0.01) = V (0.01). The contents of Au, Be, Dy, Ga, Ge, Hf, and Tb were below the limits of detection (0.02, 0.02, 0.01, 0.01, 0.01, 0.01, 0.02 mg kg-1 respectively). The concentrations of Al, As, B, Ba, Ca, Cd, Cr, Er, Fe, In, Lu, Mn, Nd, Sr, Ti, Tm, and Zr were comparable over the period the mushrooms were cultivated. The study revealed that Lentinula edodes contained As and Cd at levels potentially adverse to human health. This highlights the need to monitor these elements in food products obtained from this mushroom species and ensure that only low levels of these elements are present in cultivation substrates.

Lithium biofortification of medicinal mushrooms Agrocybe cylindracea and Hericium erinaceus.

Although an increase in dietary lithium (Li) has been suggested as a possible method for mood stabilization and for decreasing violence and suicidal rates, no Li-enriched food has entered the market. Here we continue to explore the feasibility of mushrooms in this respect and have investigated the growth, accumulation and mineral content (Ca, K, Mg and Na) of Agrocybe cylidracea and Hericium erinaceus cultivated on substrates supplemented with 0.25-1.0 mM of Li as acetate or chloride. As demonstrated, supplementation with LiCl yielded more satisfactory results, did not alter mushroom biomass, appearance, shape or size regardless of Li concentration. It also had no significant effect on mineral composition and resulted in a concentration-dependent uptake of Li and its accumulation in fruiting bodies. More promising results were found for H. erinaceus. As calculated, consumption of 100 g dw of its fruiting bodies obtained from cultivation with 1.0 mM of Li (as acetate or chloride) would constitute 69% of the provisional recommended dietary daily intake of Li set at 1.0 mg. The study highlights that H. erinaceus could be selected for further studies on Li-enriched food that concern the bioavailability of Li from mushrooms, their safety and activity in animal experimental models and eventually, human studies.

The role of selected tree species in industrial sewage sludge/flotation tailing management.

The aim of the study was to estimate the ability of ten tree and bush species to tolerate and accumulate Cd, Cu, Pb, Zn, and As species [As(III), As(V), and total organic arsenic] in industrial sewage sludge extremely contaminated with arsenic (almost 27.5 g kg(-1)) in a pot experiment. The premise being that it will then be possible to select the most promising tree/bush species, able to grow in the vicinity of dams where sewage sludge/flotation tailings are used as landfill. Six of the ten tested tree species were able to grow on the sludge. The highest content of total As was observed in Betula pendula roots (30.0 ± 1.3 mg kg(-1) DW), where the dominant As species was the toxic As(V). The highest biomass of Quercus Q1 robur (77.3 § 2.6 g) and Acer platanoides (76.0 § 4.9 g) was observed. A proper planting of selected tree species that are able to thrive on sewage sludge/flotation tailings could be an interesting and promising way to protect dams. By utilizing differences in their root systems and water needs, we will be able to reduce the risk of fatal environmental disasters.

Variations of arsenic species content in edible Boletus badius growing at polluted sites over four years.

The content of arsenic (As) in mushrooms can vary depending on the concentration level of this metalloid in the soil/substrate. The present study evaluated the content of arsenic in Boletus badius fruiting bodies collected from polluted and non-polluted sites in relation to the content of this element in overgrown substrate. It was found that mushrooms from the arsenic-polluted sites contained mean concentrations from 49 to 450 mg As kg(-1) dry matter (d.m.), with the greatest content found for specimens growing in close proximity of sludge deposits (490±20 mg As kg(-1)d.m.). The mean content of total arsenic in mushrooms from clean sites ranged from 0.03 to 0.37 mg kg(-1) It was found that B. badius could tolerate arsenic in soil substrate at concentrations of up to 2500 mg kg(-1), at least. In different years of investigation, shifts in particular arsenic forms, as well as a general increase in the accumulation of organic arsenic content, were observed. The results of this study clearly indicate that B. badius should not be collected for culinary purposes from any sites that may be affected by pollution.

Content of selected elements in Boletus badius fruiting bodies growing in extremely polluted wastes.

The aim of the study was to analyse levels of 17 trace elements and 5 major minerals in 11 Boletus badius fruiting bodies able to grow in extremely polluted waste (flotation tailings) and polluted soil in southern Poland. The presented data widen the limited literature data about the abilities of wild-growing mushroom species to grow on heavily contaminated substrates. Content of elements in waste, soil and mushrooms was analysed by flame atomic absorption spectrometry (FAAS) and cold vapour atomic absorption spectrometry (CVAAS - Hg). The industrial areas differed greatly as regards the content of elements in flotation tailings and soil; therefore differences in Ag, Ba, Cd, Co, Fe, Mo, Ni, Pb, Ca, K, Mg, Na and P accumulation in mushrooms were observed. The highest contents of elements in mushrooms were observed for: As, Al, Cu and Zn (86 ± 28, 549 ± 116, 341 ± 59 and 506 ± 40 mg kg(-1) dry matter, respectively). Calculated bioconcentration factor (BCF) values were higher than 1 for Al (15.1-16.9), Fe (10.6-24.4) and Hg (10.2-16.4) only. The main value of the presented results is the fact that one of the common wild-growing mushroom species was able to grow on flotation tailings containing over 22 g kg(-1) of As and, additionally, effective accumulation of other elements was observed. In view of the high content of the majority of analysed elements in fruiting bodies, edible mushrooms from such polluted areas are nonconsumable.

Differences in Cu content in selected mushroom species growing in the same unpolluted areas in Poland.

The aim of the study was to estimate copper (Cu) accumulation efficiency in whole-fruiting bodies of 18 edible and non-edible wild growing mushrooms collected from 27 places in the Wielkopolska Voivodeship. Mushrooms were collected each time from the same places to estimate the diversity in Cu accumulation between tested mushroom species within 3 consecutive years of study (2011-2013). The study results revealed various accumulation of Cu in the whole-tested mushroom fruiting bodies. The highest mean accumulation of Cu was observed in Macrolepiota procera (119.4 ± 20.0 mg kg(-1) dm), while the lowest was in Suillus luteus and Russula fellea fruiting bodies (16.1 ± 3.0 and 18.8 ± 4.6 mg kg(-1) dm, respectively). Significant differences in Cu accumulation between mushroom species collected in 2011 and in the two following years (2012 and 2013) were observed. The results indicated that sporadic consumption of these mushrooms was not related to excessive intake of Cu for the human body (no toxic influence on health).

Bioaccumulation of elements in three selected mushroom species from southwest Poland.

The contents of 16 minerals and trace elements (Ag, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Pt, Ti and Zn) were analyzed in edible mushrooms (Leccinum scabrum, Boletus edulis and Boletus badius) collected in southwest Poland. Content of Co, Ni and Pb was similar in all tested mushroom species, while content of Ag, Ca, Cd, Hg and Ti was significantly higher in B. edulis than in L. scabrum and B. badius. The largest differences between these species were observed for Fe and Zn accumulation. The highest contents of these elements were noted in B. badius bodies (202 ± 88 and 137 ± 24 mg kg(-1) dry matter, respectively), lower in B. edulis (131 ± 99 and 89 ± 26 mg kg(-1) dry matter, respectively) and lowest in L. scabrum. Differences in As, Cu and Cr content between tested species were observed mainly between L. scabrum and B. badius fruiting bodies. Content of Pt was below 0.01 mg kg(-1) dry matter). In the case of Mg and Mn accumulation, differences between B. edulis and B. badius were not observed (478 and 440 mg kg(-1) dry matter for Mg and 23 and 19 mg kg(-1) dry matter for Mn), and the results showed significantly higher content of these elements than in L. scabrum bodies (312 and 10 mg kg(-1) dry matter, respectively). It is worth underlining that clear accumulation shown by the bioconcentration factor (BCF>1) observed for all three mushroom species was noted in the case of elements Ag, Cd, Co, Cu, Hg, Ni and Zn only.

Efficacy of supplementation of selected medicinal mushrooms with inorganic selenium salts.

The aim of the study was to evaluate the possibility of supplementation with inorganic forms of selenium (Na2SeO4 and Na2SeO3) in concentrations of 0, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0 and 1.5 mM of three medicinal mushroom species: Agrocybe aegerita, Hericium erinaceus and Ganoderma lucidum. Tested mushroom species grew in Se additions of 0-0.6 mM (A. aegerita and H. erinaceus), while growth of G. lucidum bodies was observed for 0-0.8 mM. For the latter mushroom species, the total Se content was the highest. Content of Seorg was diverse; for control bodies it was the highest for G. lucidum (only organic forms were present), lower for A. aegerita (84% organic forms) and the lowest for H. erinaceus (56% organic forms). Accumulation of Se(IV) was generally significantly higher than Se(VI) for all tested mushroom species. There was no significant decrease of A. aegerita or G. lucidum biomass with the exception of G. lucidum bodies growing under 0.8 mM of Se species addition (15.51 ± 6.53 g). Biomass of H. erinaceus bodies was the highest under 0.2 (197.04 ± 8.73 g), control (191.80 ± 6.06 g) and 0.1 mM (185.04 ± 8.73 g) of both inorganic salts. The addition to the medium of Se salts brought about macroscopic changes in the fruiting bodies of the examined mushrooms. Concentrations exceeding 0.4 mM caused diminution of carpophores or even their total absence. In addition, colour changes of fruiting bodies were also recorded. At Se concentrations of 0.4 and 0.6 mM, A. aegerita fruiting bodies were distinctly lighter and those of H. erinaceus changed colour from purely white to white-pink.

Seasonality Affects Low-Molecular-Weight Organic Acids and Phenolic Compounds' Composition in Scots Pine Litterfall.

BACKGROUND AND AIMS: Secondary plant metabolites, including organic acids and phenolic compounds, have a significant impact on the properties of organic matter in soil, influencing its structure and function. How the production of these compounds in foliage that falls to the forest floor as litterfall varies across tree age and seasonality are of considerable interest for advancing our understanding of organic matter dynamics. METHODS: Monthly, we collected fallen needles of Scots pine (Pinus sylvestris L.) across stands of five different age classes (20, 40, 60, 80, and 100 years) for one year and measured the organic acids and phenolic compounds. RESULTS: Seven low-molecular-weight organic acids and thirteen phenolic compounds were detected in the litterfall. No differences were observed across stand age. Significant seasonal differences were detected. Most compounds peaked during litterfall in the growing season. Succinic acid was the most prevalent organic acid in the litterfall, comprising 78% of total organic acids (351.27 ± 34.27 µg g- 1), and was 1.5 to 11.0 times greater in the summer than all other seasons. Sinapic acid was the most prevalent phenolic compound in the litterfall (42.15 µg g- 1), representing 11% of the total phenolic compounds, and was 39.8 times greater in spring and summer compared to autumn and winter. Growing season peaks in needle concentrations were observed for all thirteen phenolic compounds and two organic acids (lactic, succinic). Citric acid exhibited a definitive peak in late winter into early spring. CONCLUSIONS: Our results highlight the seasonal dynamics of the composition of secondary plant metabolites in litterfall, which is most different at the onset of the growing season. Fresh inputs of litterfall at this time of emerging biological activity likely have seasonal impacts on soil's organic matter composition as well.

Copper, lead and zinc interactions during phytoextraction using Acer platanoides L.-a pot trial.

Of the many environmental factors that modulate the phytoextraction of elements, little has been learnt about the role of metal interactions. The study aimed to show how different concentrations of Cu, Pb and Zn in the cultivation medium influenced the biomass, plant development and phytoextraction abilities of Acer platanoides L. seedlings. Additionally, the impact on the content and distribution of Ca, K, Mg and Na in plant parts was studied with an analysis of phenols. Plants treated with a mixture of two metals were characterised by lower biomass of leaves and higher major elements content jointly than those grown in the salt of one element. Leaves of A. platanoides cultivated in Pb5 + Zn1, Pb1 + Zn1 and Pb1 + Zn5 experimental systems were characterised by specific browning of their edges. The obtained results suggest higher toxicity to leaves of Pb and Zn present simultaneously in Knop solution than Cu and Pb or Cu and Zn, irrespective of the mutual ratio of the concentrations of these elements. Antagonism of Cu and Zn concerning Pb was clearly shown in whole plant biomass when one of these elements was in higher concentration (5 mmol L-1) in solution. In the lowest concentrations (1 mmol L-1), there was a synergism between Cu and Zn in plant roots. Plants exposed to Zn5, Cu1 + Pb5, Pb5 + Zn1 and Cu1 + Zn1 were characterised by higher total phenolic content than the rest plants. Both the presence and the concentration of other elements in the soil are significant factors that modulate element uptake, total phenolic content, and plant development.

Physiological and morphological changes in Salix viminalis L. as a result of plant exposure to copper.

The aim of this study was to assess the response of Salix viminalis L. under model conditions to different copper concentrations and, as a consequence, potential application of the experimental results in decontamination of water with heavy metal ions (phytoaccumlation). The 14-day experiment was conducted on one-year-old cuttings of Salix viminalis L. 'Cannabina' exposed, in a phytotron, to six different copper levels in hydroponic pots. The results showed that the capacity to accumulate heavy metals was of the following order: roots > rods > shoots > leaves. The linear relationships between the accumulation efficiency of particular Salix parts were confirmed. Together with an increase in copper sorption in above-ground organs, a decrease was observed in root biomass and the length of roots, shoots and leaves. The release of low molecular weight organic acids into solution was different under various Cu levels. Glucose, fructose and sucrose contents in leaves of Salix in all treatments were higher than in control plants. Higher concentration of sugars (4 times higher compared to the control) was detected for fructose in a 2 mM Cu treatment. The total phenolics content rapidly increased only at 3 mM Cu level. Free and total salicylic acid and the glutathione contents in plants treated with copper in relation to the control were always higher and changed with increasing concentration of copper ions in the medium.