Małgorzata Wójcik

Metal accumulation strategies in plants spontaneously inhabiting Zn-Pb waste deposits

Metal (Zn, Pb, Cd, Cu, Ni, Cr) accumulation in shoots of 38 plant species spontaneously colonizing three Zn-Pb waste deposits in southern Poland was studied in order to find out if the age of the waste (30-130 years) or its type (slag or flotation residues) influence metal content in plants and to identify species potentially suitable for biomonitoring and phytoremediation. The total metal concentrations in the waste upper layers ranged from 7300 to 171,790 mg kg(-1) for Zn, from 1390 to 22,265 mg kg(-1) for Pb, and from 66 to 1,464 mg kg(-1) for Cd, whereas CaCl2-extracted fractions accounted for 0.034-0.11 %, 0.005-0.03 %, and 0.28-0.62 % of total Zn, Pb and Cd concentrations, respectively. The concentrations of Cu, Ni, and Cr in substrates and in plants were low and ranged within the background values. Metal accumulation in plant shoots was poorly correlated with both total and CaCl2-extracted forms of metals in the substrate and was highly variable among species and also specimens of the same species. The highest mean concentrations of Zn, Pb and Cd were found in Anthyllis vulneraria L. (901.5 mg kg(-1)), Echium vulgare L. (116.92 mg kg(-1)), and Hieracium piloselloides Vill. (26.86 mg kg(-1)), respectively. Besides Reseda lutea L., no species appeared to be a good indicator of polymetallic environment pollution based on chemical analysis of shoots; however, metal accumulation in the whole plant communities of a particular contaminated area might be an accurate tool for assessment of metal transfer to vegetation irrespective of the type or age of the waste. All the species studied developed a metal exclusion strategy, thus exhibiting potential for phytostabilization of metalliferous wastelands.

Morphological, physiological, and genetic variation between metallicolous and nonmetallicolous populations of Dianthus carthusianorum

Waste deposits produced by metal mining and smelting activities provide extremely difficult habitats for plant colonization and growth. Therefore, plants spontaneously colonizing such areas represent a very interesting system for studying evolution of plant adaptation and population differentiation between contaminated and noncontaminated environments. In this study, two populations of Dianthus carthusianorum, one originating from Zn-Pb waste deposit (a metallicolous population, M) and the other from unpolluted soil (a nonmetallicolous population, NM), were analyzed in respect of their morphological and physiological traits as well as genetic markers. It was found that the plants inhabiting the waste heap differed significantly from the NM plants in terms of leaf size and shape, and these differences were persistent between the first generation of the plants of both populations cultivated under uniform, controlled laboratory conditions. In contrast with the evident morphological differences, no significant differentiation between the populations regarding the physiological traits measured (accumulation of proline, anthocyanins, chlorophyll, carotenoids) was found. These traits can be regarded as neither population specific nor stress markers. The genetic variability was analyzed using 17 random amplified polymorphic DNA (RAPD) and four inter simple sequence repeat (ISSR) markers; this proved that the differentiation between the M and NM populations exists also at the genetic level. Analysis of molecular variance (AMOVA) showed that 24% of the total genetic diversity resided among populations, while 76% - within the populations. However, no significant differences in intrapopulation genetic diversity (Hj) between the M and NM populations of D. carthusianorum was found, which contradicts the theory that acquisition of adaptation mechanisms to adverse, isolated growth habitats is related to reduction in genetic diversity. Distinct genetic differences between the two populations in combination with evident morphological variation support the proposal to regard the M population of D. carthusianorum as a separate calamine ecotype.

Accumulation and tolerance of lead in two contrasting ecotypes of Dianthus carthusianorum.

Dianthus carthusianorum is one of the dominant plant species colonising the Zn-Pb waste deposits in Bolesław, Southern Poland. It differs in terms of morphology and genetics from ecotypes inhabiting non-metal-polluted areas. The response of waste-heap (metallicolous, M) and reference (nonmetallicolous, NM) ecotypes of D. carthusianorum to Pb in hydroponics was investigated and compared in this study. The plants of the M ecotype were more tolerant to Pb than these of the NM ecotype in spite of accumulation of higher concentrations of Pb. In both ecotypes, about 70-78% of Pb was retained in roots. In non Pb-treated plants, a higher glutathione (GSH) level was found in the M ecotype. After the Pb exposure, the GSH level decreased and was similar in both ecotypes. Lead treatment induced synthesis of phytochelatins (PCs) only in the plant roots, with significantly higher concentrations thereof detected in the NM ecotype. Malate and citrate concentrations were higher in the M ecotype; however, they did not change significantly upon any Pb treatment in either ecotype. The results indicated that neither PCs nor organic acids were responsible for the enhanced Pb tolerance of the waste-heap plants.

The effect of silicon on maize growth under cadmium stress

The effects of silicon (Si) supply (0, 0.1, 0.5, 1.5, 3.0, and 5.0 mM Si) on maize seedling growth, Si and Cd accumulation, and thiol peptide synthesis under Cd stress conditions were studied. The addition of Si to the growth medium resulted in the significantly higher Si accumulation in plant tissues. The average values of growth parameters (root and shoot fresh weights and root net elongation rates) showed a beneficial role of Si on growth of non-Cd-treated plants, while there was no evidence that silicon mitigated Cd toxicity in maize seedlings. Cadmium exposure depressed plant growth and induced phytochelatin (PC) synthesis. The accumulation of Cd and PCs in roots significantly decreased with increasing Si concentrations in the nutrient solution; however, their accumulation in shoots was not changed in the presence of Si.

Effect of cadmium on selected physiological and morphological parameters in metallicolous and non-metallicolous populations of Echium vulgare L.

Cadmium tolerance of three populations of Echium vulgare L., naturally occurring on two Zn-Pb waste deposits (metallicolous populations M1, M2) and on an uncontaminated site (non-metallicolous population, NM) was investigated. The plants were cultivated in hydroponics at 0, 5, 15, 30, or 50μM Cd for 14 days. Although Cd reduced the content of photosynthetic pigments indifferently in the three populations, plant growth parameters and root viability analyses confirmed different Cd tolerances decreasing in the order M1>M2>NM in the populations studied. Organic acids (tartrate, malate, citrate, succinate) were not responsible for the elevated Cd tolerance of the metallicolous populations, although malate and citrate might participate in Cd detoxification in the roots of the M1 and M2. Phytochelatin concentrations were higher in the roots of M1 and M2 populations of E. vulgare, suggesting their role in Cd detoxification and different Cd tolerances.

Comparison of some secondary metabolite content in the seventeen species of the Boraginaceae family

Abstract Context: The Boraginaceae family comprises plants that have important therapeutic and cosmetic applications. Their pharmacological effect is related to the presence of naphthaquinones, flavonoids, terpenoids, phenols, or purine derivative – allantoin. Objective: In the present study, comparison of some secondary metabolite content and phytochemical relationship between 17 species of the Boraginaceae family were analyzed. Materials and methods: High performance capillary electrophoresis (HPCE) was used to perform a chemometric analysis in the following Boraginaceae species: Anchusa azurea Mill., Anchusa undulata L., Borago officinalis L., Buglossoides purpurocaerulea (L.) I.M. Johnst., Cerinthe minor L., Cynoglossum creticum Mill, Echium italicum L., Echium russicum J.F. Gmel., Echium vulgare L., Lindelofia macrostyla (Bunge) Popov (syn. Lindelofia anchusoides (Lindl.) Lehm.), Lithospermum officinale L., Nonea lutea (Desr.) DC., Omphalodes verna Moench (syn. Cynoglossum omphaloides L.), Pulmonaria mollis Wulfen ex Hornem., Pulmonaria obscura Dumort., Symphytum cordatum Waldst. & Kit ex Willd., and Symphytum officinale L. Results: Six active compounds in shoot extracts (allantoin, p-hydroxybenzoic acid, rutin, hydrocaffeic acid, rosmarinic acid, and chlorogenic acid) and four compounds in root extracts (allantoin, hydrocaffeic acid, rosmarinic acid, and shikonin) were identified. The presence and abundance of these compounds were used for the characterization of the species and for revealing their phytochemical similarity and differentiation. Discussion and conclusion: The present study provides the first comprehensive report of the extraction and quantification of several compounds in Boraginaceae species (some of them for the first time). Among the 17 species studied, species with potentially high pharmacological activity were recognized.

Does methyl jasmonate modify the oxidative stress response in Phaseolus coccineus treated with Cu

The contribution of methyl jasmonate (MJ) as a signal molecule able to take part in the defense mechanism against copper (Cu)-imposed oxidative stress was studied in the leaves and roots of runner bean (Phaseolus coccineus) plants. Roots of plants cultivated hydroponically were preincubated in MJ (10µM) for 1h or 24h and subsequently exposed to Cu (50µM) for 5h (short-term experiment) or 5 days (long-term experiment). Enzymatic (activity of superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX; guaiacol peroxidase, POX) and non-enzymatic (accumulation of malondialdehyde, MDA; homoglutathione, hGSH; proline; anthocyanins; low molecular weight organic acids, LMWOAs) responses were determined in the leaves and roots. The antioxidative defense mechanism was significantly activated after Cu supplementation. In most cases, activities of ROS (reactive oxygen species) scavenging enzymes like SOD, CAT, APX, POX, as well as MDA, hGSH and proline concentrations increased following Cu exposure. MJ showed a time-dependent effect on antioxidative enzymes activity. In the short-term experiment, MJ elevated CAT, APX and POX activities in the roots, and POX activity in the leaves of non-Cu-treated plants. In the long-term experiment, MJ not only decreased POX and partially CAT activity in the roots, but also increased the MDA level and partially CAT activity in the leaves of the control plants. In Cu-treated plants, MJ reduced APX, but elevated POX activity in the leaves after 5-h exposure. After 5-day-Cu treatment, MJ inhibited POX activity in the leaves and mainly reduced SOD and CAT activities in the roots. Moreover, in the long-term experiment, MJ reduced tartrate and pyruvate in the leaves of Cu-stressed plants, but mostly elevated tartrate and malate in the roots comparing with Cu alone treatment. MJ alone and under Cu excess did not alter accumulation of MDA, hGSH and proline comparing with Cu alone, but partially elevated anthocyanin concentration. The results indicated that MJ was both partially potent in modifying the antioxidative enzymes activity and metabolites accumulation in non-stress and Cu-stress conditions.

Physiological mechanisms of adaptation of Dianthus carthusianorum L. to growth on a Zn-Pb waste deposit - the case of chronic multi-metal and acute Zn stress

AimsThis study investigates the response of metallicolous (M) and nonmetallicolous (NM) ecotypes of Dianthus carthusianorum L. to chronic multi-metal and acute Zn stress.MethodsPlants were cultivated on the Zn-Pb waste heap substrate and under Zn excess in hydroponics. Growth parameters as well as accumulation of organic acids and thiol peptides were determined as a function of metal accumulation.ResultsWhen grown on the metalliferous substrate, the M plants showed less phytotoxicity symptoms, lower foliar metal (Zn, Pb, Cd) accumulation, higher malate and citrate but lower glutathione content than the NM plants. When exposed to Zn excess in hydroponics, the M ecotype was also more tolerant but accumulated more Zn in comparison with the NM ecotype, accompanied by greater malate and citrate concentrations in the shoots, which were however not affected by increasing Zn doses. No phytochelatins were detected under any experimental conditions.ConclusionsBoth constitutive and adaptive tolerance was found in D. carthusianorum. Under chronic metal stress, enhanced tolerance results from restricted metal uptake to the shoots and probably from detoxification by organic acids; however, under acute Zn stress it is not related to diminished metal uptake or organic acids. Glutathione and phytochelatins are not implicated in adaptive metal tolerance.

Selected secondary metabolites in Echium vulgare L. populations from nonmetalliferous and metalliferous areas

The aim of this study was to evaluate the effect of severe environmental conditions prevailing on metalliferous waste heaps and heavy metal-contaminated growth substrates on accumulation of selected secondary metabolites, antioxidant capacity, and heavy metal concentration in two metallicolous (MC, MZ) and one nonmetallicolous (NM) populations of Echium vulgare L. The shoots and the roots of the three studied populations were collected from their natural habitats. Additionally, the plants were cultivated on different growth substrates, i.e. a contaminated substrate obtained from the areas of growth of the MZ and MC populations and an uncontaminated one from the NM population site. Several compounds, i.e. allantoin, rutin, rosmarinic acid, chlorogenic acid, and 4-hydroxybenzoic acid were identified in the shoots. Moreover, rosmarinic acid, allantoin, and shikonin were measured in the roots. The adverse environmental conditions contributed to a ca. 10- and 4-fold increase in the concentration of allantoin in the roots and shoots, respectively, as well as a ca. 4-fold and ca. 3-fold increase in the level of 4-hydroxybenzoic acid and shikonin, respectively, in comparison with the plants from the uncontaminated site. Similarly, a great impact of the contaminated substrate on the compounds was demonstrated in the soil experiment. Regardless of the populations, even ca. 20-fold higher levels of allantoin and shikonin were observed in plants grown on the MC and MZ substrates. In contrast, the chlorogenic acid concentration was lower in plants collected from the metalliferous areas and in all populations cultivated on the contaminated substrates in comparison with plants from the uncontaminated soil. Unambiguous results were obtained in the case of rutin, i.e. decreased accumulation in both metallicolous populations from the natural environment and increased accumulation in plants grown on the contaminated substrates. The high concentrations of heavy metals in the substrates contributed to high HM concentrations in plant tissues. However, some differences were observed between the metallicolous and nonmetallicolous populations - the accumulation of metals was lower in the shoots and higher in the roots of the NM population, compared with the MZ and MC populations.