Consortium of Higher Aquatic Plants and Microalgae Designed to Purify Sewage of Heavy Metal Ions

We selected higher aquatic plants (HAP) and microalgae possessing a high sorption capacity in respect to heavy metals to form a consortium designed to purify contaminated aquatic ecosystems. Accumulation of heavy metals Cd²⁺, Cu²⁺, Pb²⁺, and Zn²⁺ was investigated in plants Pistia stratiotes, Elodea canadensis, and Lemna minor and green microalgae Chlorella vulgaris ВВ-2, Ankistrodesmus sp. ВI-1, Chlamydomonas reinhardtii В-4, and Scеnеdеsmus quadricauda В-1. It was found that intense accumulation of metals occurs in cultures of HAP Pistia stratiotes and Elodea canadensis. These plants are macroconcentrators of zinc, lead, and copper and microconcentrators of cadmium. Out of the examined cultures of microalgae, effective bioaccumulators of heavy metals were C. vulgaris ВВ-2 and Ankistrodesmus sp. ВI-1. It was shown that heavy metals are selectively taken up from the medium in the series Zn²⁺ > Cu²⁺ > Cd²⁺ > Pb²⁺. In order to produce a consortium of higher aquatic plants and microalgae for purification of polluted aquatic ecosystems, we investigated interaction of HAP P. stratiotes and E. canadensis with microalgae C. vulgaris ВВ-2 and Ankistrodesmus sp. ВI-1 in the course of their cocultivation. Neutral relations were detected between the cells of microalgae C. vulgaris ВВ-2 and Ankistrodesmus sp. ВI-1 and HAP E. canadensis. At the same time, the cells of Ankistrodesmus sp. ВI-1 and HAP P. stratiotes formed a symbiosis. Microscopic examination showed numerous points where the cells of microalgae Ankistrodesmus sp. ВI-1 were attached to the roots of P. stratiotes plants. We tested an opportunity to employ the association between P. stratiotes and Ankistrodesmus sp. ВI-1 for purification of simulated wastewater polluted with heavy metal ions. This consortium proved to be capable of eliminating contaminants from the sewage, reducing their level in the sewage to standard values, and active accumulation of heavy metal ions.     

Responses of <Emphasis Type="Italic">Typha orientalis</Emphasis> Roots to Pb<Superscript>2+</Superscript> Stress

To investigate phytoremediation potential of Typha orientalis Presl in removing Pb²⁺ from polluted water, relevant experiments were conducted to evaluate responses activated by Pb²⁺ (0.25–2 mM) in T. orientalis roots over a period of ten days. Pb contents in subcellular fractions decreased in the following order: cell wall > organelle > soluble fraction. Most of Pb was located in cell wall and membrane system. Contents of K and Ca declined in T. orientalis roots under Pb²⁺ stress, but an opposite effect was noted for some mineral elements (Mg, Cu, Zn, and Fe). H₂O₂ level increased in a concentration-dependent manner, which induced oxidative stress. However, significant reduction in levels of O ₂ ^·? and malondialdehyde (MDA) were observed in all Pb²⁺ treatment groups. Findings indicated toxicity of Pb²⁺ to T. orientalis in terms of inducing oxidative stress and causing imbalance in mineral elements. However, T. orientalis also resisted Pb²⁺-induced damage through isolation mechanism, which involves cell wall and membrane systems.     

Associations of <Emphasis Type="Italic">CTLA4</Emphasis> +49 A/G Dimorphism and HLA-DRB1*/DQB1* Alleles With Type 1 Diabetes from South India

The aim of present study was to elucidate the association of CTLA4 +49 A/G and HLA-DRB1*/DQB1* gene polymorphism in south Indian T1DM patients. The patients and controls (n?=?196 each) were enrolled for CTLA4 and HLA-DRB1*/DQB1* genotyping by RFLP/PCR-SSP methods. The increased frequencies of CTLA4 ‘AG’ (OR?=?1.99; p?=?0.001), ‘GG’ (OR?=?3.94; p?=?0.001) genotypes, and ‘G’ allele (OR?=?2.42; p?=?9.26?×?10^?8) were observed in patients. Reduced frequencies of ‘AA’ (OR?=?0.35; p?=?7.19?×?10^?7) and ‘A’ (OR?=?0.41; p?=?9.26?×?10^?8) in patients revealed protective association. Among HLA-DRB1*/DQB1* alleles, DRB1*04 (OR?=?3.29; p?=?1.0?×?10^?5), DRB1*03 (OR?=?2.81; p?=?1.9?×?10^?6), DQB1*02:01 (OR?=?2.93; p?=?1.65?×?10^?5), DQB1*02:02 (OR?=?3.38; p?=?0.0003), and DQB1*03:02 (OR?=?7.72; p?=?0.0003) were in susceptible association. Decreased frequencies of alleles, DRB1*15 (OR?=?0.32; p?=?2.55?×?10^?7), DRB1*10 (OR?=?0.45; p?=?0.002), DQB1*06:01 (OR?=?0.43; p?=?0.0001), and DQB1*05:02 (OR?=?0.28; p?=?2.1?×?10^?4) in patients were suggested protective association. The combination of DRB1*03+AG (OR?=?5.21; p?=?1.4?×?10^?6), DRB1*04+AG (OR?=?2.14; p?=?0.053), DRB1*04+GG (OR?=?5.21; p?=?0.036), DQB1*02:01+AG (OR?=?4.44; p?=?3.6?×?10^?5), DQB1*02:02+AG (OR?=?20.9; p?=?9.5?×?10^?4), and DQB1*02:02+GG (OR?=?4.06; p?=?0.036) revealed susceptible association. However, the combination of DRB1*10+AA (OR?=?0.35; p?=?0.003), DRB1*15+AA (OR?=?0.22; p?=?5.3?×?10^?7), DQB1*05:01+AA (OR?=?0.45; p?=?0.007), DQB1*05:02+AA (OR?=?0.17; p?=?1.7?×?10^?4), DQB1*06:01+AA (OR?=?0.40; p?=?0.002), and DQB1*06:02+AG (OR?=?0.34; p?=?0.001) showed decreased frequency in patients, suggesting protective association. In conclusion, CTLA4/HLA-DR/DQ genotypic combinations revealed strong susceptible/protective association toward T1DM in south India. A female preponderance in disease associations was also documented.     

Expressions of some antioxidant genes in SH-SY5Y cells treated with β-lapachone,morphine and electromagnetic field

β-Lapachone (β-Lap), morphine (Mor), and electromagnetic field (EMF) generate reactive oxygen species. The goal of the present study was to examine the effects of Mor and EMF, in combination with β-Lap on the cell growth inhibition and expression of several antioxidant genes. The 0.50 mT intensity of 50 Hz EMF and two exposure conditions (“15 min field-on/15 min field-off” and “30 min field-on continuously”) on SH-SY5Y cells were used. The effects of Mor and EMF, in combination with β-Lap on cell growth inhibition and the expression levels of several antioxidant genes (NQO1, NQO2, SOD1, SOD2, CAT, GSTO1, GSTM2, GSTM3, GSTP1, MGST1, MGST3) in SH-SY5Y cells were measured. The relative mRNA levels were calculated according to the \({{\text{2}}^ - }^{{\Delta \Delta {{\text{C}}_{\text{t}}}}}\). Whereas NQO1 mRNA level decreased in the “15 min field-on/15 min field-off” condition, the expression level of NQO2 was increased. Both NQO1 and NQO2 expressions increased in Mor treated cells. IC₅₀ values of β-Lap in combination with Mor, EMF, and “Mor?+?EMF” were higher than cells treated only with β-Lap. The NQO1 expression level in the cells treated with β-Lap was higher than the other treatments, indicating that β-Lap induces the expression of NQO1. Moreover, multiple linear regression analysis indicated that NQO1 mRNA levels were associated positively with β-Lap and negatively with EMF. At least in part, the mRNA levels of NQO1 were associated with IC₅₀ values of β-Lap in designed treatments. There is a negative association between mRNA levels of NQO1 and IC₅₀ values of β-Lap but not NQO2.     

The effect of genetic environment on locus-specific instability of the <Emphasis Type="Italic">yellow</Emphasis> gene in the Uman’ population of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

The effects of genotype of the laboratory strains, C(1)DX, ywf/Y, 23.5 MRF/CyL ⁴, and C(1)DX,yf; π₂, on locus-specific instability in the yellow gene of the strains y ^2-217, y ^2-715, and y ^2-700 from Uman’ population of Drosophila melanogaster was studied. Crosses of the males from Uman’-derived lines with the C(1)DX,ywf/Y females yielded a cascade of derivatives, mostly consisting of y ⁺ and y ² alleles, while their crosses with the 23.5 MRF/CyL ⁴ and C(1)DX,yf; π₂ females mostly resulted in the appearance of y ⁺ and y ¹ derivatives. The genomes of laboratory strains used in the study contained the full-sized hobo elements, which could differ from one another relative to the structure of variable region and affinity to different DNA sequences.     

Cloning and Functional Analysis of <Emphasis Type="Italic">SaCLCc1</Emphasis>, a Gene Belonging to the Chloride Channel Family (<Emphasis Type="Italic">CLC</Emphasis>), from the Halophyte <Emphasis Type="Italic">Suaeda altissima</Emphasis> (L.) Pall.

One of the genes of the CLC (Chloride Channel) family, SaCLCc1, from the halophyte Suaeda altissima (L.) Pall. was cloned. To investigate the function of SaCLCc1, it was expressed in the S. cerevisiae deletion mutant Δgef1::LEU2 for the only gene of the CLC family in this organism. The growth of the transformed SaCLCc1-expressing mutant Δgef1 was restored when cells were grown in Fe²⁺-deficient YPEG medium, in minimal synthetic media SD and SR (pH 7.0), and in rich YPD medium containing Mn²⁺. The complementation of the Δgef1 mutant phenotype with the SaClCc1 gene indicates the involvement of the SaClCc1 protein in the transport of Cl^– ions.     

Waste water treatment and metal (Pb<Superscript>2+</Superscript>, Zn<Superscript>2+</Superscript>) removal by microalgal based stabilization pond system

A case study was undertaken for the treatment of domestic wastewater generated at village of Sanghol, Distt. Fatehgarh Sahib, Punjab (India), using a schematic designed algal and duckweed based stabilization pond system, which is discussed here for winter months only (November to March) as there was no growth of duckweeds and only algae dominated the whole system. A proficient increase in pH and dissolved oxygen was observed after the treatment with reduction in chemical oxygen demand and biochemical oxygen demand by 93% and 79% respectively. Chlorella sp. was the dominating algal species in the stabilization pond water during entire period and was studied for its Zn²⁺ and Pb²⁺ metal removal efficiency. 60–70% removal of Zn²⁺ was observed from culture medium containing 5–20 mg L^?1 Zn²⁺, which declined to 42% at 50 mg L^?1. A constant decline in cell number from 538 × 10⁵ to 8 × 10⁵ cells ml^?1 was observed indicating zinc toxicity to Chlorella. Lead was maximally removed by 66.3% from culture medium containing 1 mg L^?1. The lead removal efficiency was 45 50 % at higher 5 to 20 mg L^?1 of external lead concentrations. The increase in cell number indicated no signs of Pb²⁺ toxicity up to 20 mg L^?1. The maximum uptake (q _max) by live Chlorella biomass for both Zn²⁺ and Pb²⁺ was 34.4 and 41.8 mg/g respectively.     

Dependence of expression of regulatory master genes of embryonic development in pancreatic cancer cells on the intracellular concentration of the master regulator PDX1

Exogenous expression of the gene encoding the pancreatic master regulator PDX1 in cell lines with different degrees of differentiation of pancreatic cancer cells is accompanied by changes in the expression of known master genes involved in cancer progression. In BxPC3^PDX+ cells, as compared to BxPC3^PDX–, we detected an increased expression of the following genes: NKX6.1 (2 times), NR5A2 (2.5 times), KLF5 (1.8 times), ZEB1 (3 times), and ONECUT1 (1.3 times), as well as a decreased expression of MUC1 and SLUG genes (3 and 2 times, respectively). In PANC1^PDX+ cells, as compared to the control PANC1^PDX– cells, we detected a decreased expression of ISL1 (2 times) and an increased expressed of KRT8 (2 times) and MUC1 (by 30%). In the high-grade cell lines (including the BxPC3 line studied), the total content of sites containing the marks of active enhancers was higher than that in the low-grade cell lines (PANC1).     

Effect of selenium on growth and antioxidant capacity of <Emphasis Type="Italic">Triticum aestivum</Emphasis> L. during development of lead-induced oxidative stress

Effects of two selenium concentrations—0.4 and 0.8 mg Se⁶⁺ per kilogram of soil (treatments Se0.4 and Se0.8)—on seedling growth, chlorophyll content (Chl (a + b)), the content of thiobarbituric acidreactive substances (TBARs) indicative of peroxidation rates, and the activities of antioxidant enzymes (ascorbate peroxidase, AsP; glutathione reductase, GR; and guaiacol peroxidase, GPX) were studied in roots and leaves of wheat (Triticum aestivum L., cv. Triso) plants that were exposed for 14 days to oxidative stress induced by 50 and 100 mg Pb²⁺ per kilogram of soil (treatments Pb50 and Pb100, respectively). The pollution of soil with Pb²⁺ inhibited growth, lowered Chl (a + b) content, and intensified peroxidation. The content of TBARs increased by 44 and 72% in leaves and by 25 and 45% in roots for treatments Pb50 and Pb100, respectively. Activities of the antioxidant enzymes GR and GPX were higher in Pb²⁺-treated than in untreated (control) plants. The introduction of Se⁶⁺ into Pb²⁺-free soil (treatment Se0.4) was found to promote growth, stimulate AsP activity by 40% in leaves, and enhance AsP, GR, and GPX activities in roots by 38, 33, and 74%, respectively. The content of TBARs was reduced in Se⁶⁺-treated plants. By contrast, the treatment Se0.8 suppressed growth, elevated TBARs content, and stimulated activities of antioxidant enzymes in roots and leaves. The addition of 0.4 mg Se⁶⁺/kg to Pb²⁺-contaminated soil alleviated the negative influence of lead on plant growth, whereas the addition of 0.8 mg Se⁶⁺/kg aggravated the effect of Pb²⁺ contamination, especially in treatment (Pb100+Se0.8). Thus, the effectiveness of exogenous Se⁶⁺ application on growth and adaptive potential of plants cultivated under optimal pollutant-free conditions and on soils contaminated with lead depended on the concentration of Se⁶⁺ supplemented to soil and on the content of the stressor agent.     

Karyotypic study of five Lutjanid species using conventional and Ag-NORs banding techniques

The first cytogenetic comparisons of five snapper species from Thailand were presented here. Renal cell samples were taken from blacktail snapper (Lutjanus fulvus), five lined snapper (L. quinquelineatus), dory snapper (L. fulviflamma), brownstripe red snapper (L. vitta), and mangrove red snapper (L. argentimaculatus). The mitotic chromosome preparation was prepared directly from kidney cells. Conventional staining and Ag-NOR banding techniques were applied to stain the chromosomes. The results exhibited that all five snapper species have the diploid chromosome numbers of 2n = 48 and the fundamental numbers (NF) of 48. The presences of large, medium, and small telocentric chromosomes were 22-24-2, 24-20-4, 36-10-2, 28-16-4 and 36-10-2, respectively. The Ag- NORs banding technique provides the pair of nucleolar organizer regions (NORs) at subcentromeric region of the long arm of the respective telocentric chromosome pairs 9, 1, 3, 4 and 9. Their karyotype formulas is as follows: L. fulvus (2n = 48): L ₂₂ ^t + M ₂₄ ^t + S ₂ ^t , L. quinquelineatus (2n = 48): L ₂₄ ^t + M ₂₀ ^t + S ₄ ^t , L. fulviflamma (2n = 48): Lt36 + Mt10 + St2, L. vitta (2n = 48): L ₂₈ ^t + M ₁₆ ^t + S ₄ ^t , and L. argentimaculatus (2n = 48): L ₃₆ ^t + M ₁₀ ^t + S ₂ ^t .     

Generation of an <Emphasis Type="Italic">Rtel1</Emphasis>-<Emphasis Type="Italic">CreERT2</Emphasis> knock-in mouse model for lineage tracing RTEL1+ stem cells during development

Regulator of telomere length 1 (RTEL1) DNA helicase has been demonstrated to be essential for the maintenance of telomeres and genomic stability. This function of RTEL1 could be required for protecting stem cells from genomic mutations as suggested by its selective expression in stem cell-zones, as well as by RTEL1 mutations identified in Hoyeraal-Hreidarsson syndrome, a severe dyskeratosis congenita that targets primarily stem cell compartments. As a first step to establish a role of RTEL1 in stem cells, we generated an Rtel1^CreERT2 mouse allele in which a tamoxifen-inducible Cre (CreERT2) cDNA was specifically knocked into the Rtel1 genomic locus and controlled by the endogenous Rtel1 regulatory elements. By crossing with a Cre-dependent LacZ reporter mouse strain (R26R^LacZ), we further demonstrated that Cre activity in Rtel1^CreERT2 mice could be specifically induced by tamoxifen, which allowed the fate of RTEL1+ cells to be traced at various stages of development. Using this tracing assay, we showed for the first time that RTEL1+ cells in the intestine and the testis can act as stem cells that have the capacity to self-renew and differentiate into progeny cells. Therefore, the Rtel1^CreERT2 mice generated in this study will be a valuable transgenic tool to explore the function of RTEL1 in stem cells.     

Salt oversensitivity derived from mutation breeding improves salinity tolerance in barley <Emphasis Type="Italic">via</Emphasis> ion homeostasis

Salt stress imposes a major environmental threat to agriculture, therefore, understanding the basic physiology and genetics of cell under salt stress is crucial for developing any breeding strategy. In the present study, the expression profile of genes involved in ion homeostasis including salt overly sensitive (HvSOS1, HvSOS2, HvSOS3), vacuolar Na⁺/H⁺ antiporter (HvNHX1), and H⁺-ATPase (HVA) along with ion content measurement were investigated in two genotypes of Hordeum vulgare under 300 mM NaCl. The gene expressions were measured in the roots and shoots of a salt-tolerant mutant genotype M4-73-30 and in its wild-type cv. Zarjou by real-time qPCR technique. The critical differences between the salt-tolerant mutant and its wild-type were observed in the expressions of HvSOS1 (105-fold), HvSOS2 (24-fold), HvSOS3 (31-fold), and HVA (202-fold) genes in roots after 6-h exposure to NaCl. The parallel early up-regulation of these genes in root samples of the salt-tolerant mutant genotype indicated induction of Na⁺/H⁺ antiporters activity and Na+ exclusion into apoplast and vacuole. The earlier up-regulation of HvSOS1, HVA, and HvNHX1 genes in shoot of the wild-type genotype corresponded to the relative accumulation of Na⁺ which was not observed in salt-tolerant mutant genotype because of efficient inhibitory role of the root in Na+ transport to the shoot. In conclusion, the lack of similarity in gene expression patterns between the two genotypes with similar genetic background may confirm the hypothesis that mutation breeding could change the ability of salt-tolerant mutant genotype for efficient ion homeostasis via salinity oversensitivity response.     

Association of polymorphic markers of chemokine genes,their receptors,and <Emphasis Type="Italic">CD14</Emphasis> gene with coronary atherosclerosis

Atherosclerosis represents an inflammatory response to the disturbance of the endothelial layer in the arterial bloodstream. In the present study, an analysis of associations of polymorphic markers for the genes controlling synthesis of proteins involved in atherosclerosis pathogenesis in coronary atherosclerosis (CA) patients (217 subjects) and in a control group (250 subjects) was conducted. The following genes were examined: rs991804 (CCL2 gene), rs1126579 (CXCR2 gene), rs4074 (CXCL1 gene), rs4073 (CXCL8 gene), rs333 (CCR5 gene), rs2471859 (CXCR4 gene), rs1801157 (CXCL12 gene), and rs2569190 (CD14 gene). Using the Monte Carlo and Markov chain (APSampler) method, allele/genotype combinations associated with both low and high CA risk were revealed. The most important findings included the following: CXCR4*T/T + CCL2*C + CCR5*I/I (P_perm = 1 × 10^–6, OR = 0.44, 95% CI 0.3–0.63), CXCR2*C + CD14*C + CXCL12*G + CCL2*C + CCR5*D (P_perm = 4 × 10^–6, OR = 5.78, 95% CI 2.34–14.28), CD14*C + CCL2*C/C + CCR5*D (P_perm = 6.3 × 10^–6, OR = 5.81, 95% CI 2.17–15.56), CXCL8*A + CXCR2*C + CD14*T + CXCR4*C (P_perm = 0.01, OR = 3.21, 95% CI 1.63–6.31).     

A unique metallothionein-engineered in <Emphasis Type="Italic">Escherichia coli</Emphasis> for biosorption of lead,zinc, and cadmium; absorption or adsorption?

The present study introduced and evaluated modification of E. coli BL21 (DE3) to improve its biosorption capacity by the transfer of the Corynebacterium glutamicum metallothionein gene (C.gMT). The C.gMT sequence was extracted and cloned in pET28a vector and the ligation product was transferred into E. coli BL21 (DE3). It has been also submitted to the GenBank database (accession number KJ638906.1). The performance of the recombinant bacterium was evaluated at different metal ions concentrations, contact times, pH values, and co-ions. The results show that recombinant BL21 (DE3) was able to uptake Pb⁺², and Zn⁺² at greater percentages than could BL21 (DE3). The optimum pH for the removal of each heavy metal was different. As contact time increased, Pb⁺² and Zn⁺² biosorption by the recombinant bacterium increased, while the biosorption of Cd⁺² remained at a nearly steady rate for contact times of more than 1 h. Increasing the concentrations of Pb⁺² and Zn⁺² in solution increased biosorption of these metals by the recombinant BL21 (DE3) over that of Cd⁺². It could be hypothesized that Pb⁺² and Zn⁺² removal by C.gMT-engineered BL21 (DE3) occurred mainly via intracellular biosorption (absorption) and that Cd⁺² was mainly taken up through cell surface biosorption (adsorption).     

Over-expression of tobacco <Emphasis Type="Italic">UBC1</Emphasis> encoding a ubiquitin-conjugating enzyme increases cadmium tolerance by activating the 20S/26S proteasome and by decreasing Cd accumulation and oxidative stress in tobacco (<Emphasis Type="Italic">Nicotiana tabacum</Emphasis>)

Ubiquitin (Ub)-conjugating enzyme (UBC, E2) receives Ub from Ub-activating enzyme (E1) and transfers it to target proteins, thereby playing a key role in Ub/26S proteasome-dependent proteolysis. UBC has been reported to be involved in tolerating abiotic stress in plants, including drought, salt, osmotic and water stresses. To isolate the genes involved in Cd tolerance, we transformed WT (wild-type) yeast Y800 with a tobacco cDNA expression library and isolated a tobacco cDNA, NtUBC1 (Ub-conjugating enzyme), that enhances cadmium tolerance. When NtUBC1 was over-expressed in tobacco, cadmium tolerance was enhanced, but the Cd level was decreased. Interestingly, 20S proteasome activity was increased and ubiquitinated protein levels were diminished in response to cadmium in NtUBC1 tobacco. By contrast, proteasome activity was decreased and ubiquitinated protein levels were slightly enhanced by Cd treatment in control tobacco, which is sensitive to Cd. Moreover, the oxidative stress level was induced to a lesser extent by Cd in NtUBC1 tobacco compared with control plants, which is ascribed to the higher activity of antioxidant enzymes in NtUBC1 tobacco. In addition, NtUBC1 tobacco displayed a reduced accumulation of Cd compared with the control, likely due to the higher expression of CAX3 (Ca²⁺/H⁺ exchanger) and the lower expression of IRT1 (iron-responsive transporter 1) and HMA-A and -B (heavy metal ATPase). In contrast, atubc1 and atubc1atubc2 Arabidopsis exhibited lower Cd tolerance and proteasome activity than WT. In conclusion, NtUBC1 expression promotes cadmium tolerance likely by removing cadmium-damaged proteins via Ub/26S proteasome-dependent proteolysis or the Ub-independent 20S proteasome and by diminishing oxidative stress through the activation of antioxidant enzymes and decreasing Cd accumulation due to higher CAX3 and lower IRT1 and HMA-A/B expression in response to 50 µM Cd challenge for 3 weeks.     

Effects of cadmium and lead stress on somatic embryogenesis of coniferous species. Part II: Changes of thiol substances

Conifers are often used as biomarkers of industrial pollution; however, little is known about the effects of heavy metals on them because only a few species have been tested. The aim of this work was to investigate the effects of cadmium (Cd²⁺) and lead (Pb²⁺) at three different concentrations (50, 250, and 500 µM) on the detoxification potential of Abies alba and Picea abies embryogenic cell masses throughout the 21-day proliferation period. Embryogenic cell masses of A. alba and P. abies responded to treatment with cadmium and lead by inducing phytochelatins and their biosynthetic intermediates. With increasing heavy metal concentrations, glutathione was used for the synthesis of phytochelatins enabling the tissues to bind to heavy metal ions and thereby avoiding the production of reactive oxygen species. Lead in A. alba and cadmium in both species caused similar increases of all antioxidative thiol compounds; thus, similar mechanisms involving a heavy metal-induced stress response can be assumed. In P. abies, the lowest lead concentration tested provoked the highest antioxidative response. Since a very low uptake of lead into the tissue was observed, the higher resistance of P. abies can be attributed to its ability to reduce lead uptake after longer exposure times. The results of cadmium treatment of both species and lead treatment of A. alba indicated the possibility of testing these coniferous species as potential phytoremediators. This is the first study to analyze the effects of heavy metals on the low-molecular-weight plant thiol content in A. alba embryogenic cell masses.