Heavy metal contamination, one of the greatest global problems, not only endangers humans and animals but also negatively affects plants. New trends, the production and industrial applications of metals in nanoforms, lead to release of large amounts of nanoparticles into the environment. However, the influence of nanoparticles on living organisms is not well understood. Cadmium is a heavy metal not essential for plants, and to its phytotoxicity also contributes its chemical similarity to zinc. It has been recorded that zinc at low concentrations reduces the toxicity of cadmium, but our results with ZnO nanoparticles did not proved it. In contrast, ZnO nanoparticles significantly increased the negative effect of cadmium, which was reflected mainly in changes in the content of photosynthetic pigments.
Zinc belongs to the mineral elements, the so-called micronutrients, which are essential for all types of plants. Embedding itself into the enzymes associated with proteosynthesis and energy processes, zinc is necessary for maintaining the integrity of biomembranes and also plays an important role in the development of seeds and generative organs. This review focuses on summarising the findings on the interaction of zinc and plants and translates into the knowledge of the effect of zinc nanoparticles on plants. The findings include an overview of both positive and negative effects on plants. In conclusion there is a great interest in nano-zinc as improving the knowledge about individual forms of zinc and their uptake and assimilation within higher plants may be the first step towards a wider involvement of zinc nanoparticles into agriculture.
- MeSH
- kovové nanočástice * chemie toxicita MeSH
- látky znečišťující životní prostředí chemie metabolismus toxicita MeSH
- nanotechnologie MeSH
- půda chemie MeSH
- rostliny metabolismus MeSH
- zemědělství MeSH
- zinek * chemie metabolismus toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Clarifying the connection between metal exposure and anatomical changes represents an important challenge for a better understanding of plant phytoextraction potential. A hydroponic screening experiment was carried out to evaluate the effects of combined interactions of Cd and Zn on mineral uptake (Mg, K, Ca, Na) and on the physiological and anatomical characteristics of Brassica napus L cv. Cadeli, Viking, and Navajo. Plants were exposed to 5 μM Cd (CdCl2), 10 μM Zn (ZnSO4), or both Cd + Zn, for 14 days. Cadmium exposure led to a significant reduction in root growth, shoot biomass, and chlorophyll content. After Cd-only and Cd + Zn treatment, primary root tips became thicker and pericycle cells were enlarged compared to the control and Zn-only treatment. No differences between metals were observed under UV excitation, where all treatments showed more intensive autofluorescence connected with lignin/suberin accumulation compared to control conditions. The highest concentrations of Cd and Zn were found in the roots of all tested plants, and translocation factors did not exceed the threshold of 1.0. The root mineral composition was not affected by any treatment. In the shoots, the Mg concentration slightly increased after Cd-only and Cd + Zn treatments, whereas Zn-only treatment caused a sharp decrease in Ca content. Slight increases in K were seen after the addition of Zn. Significantly higher concentrations of Na were induced by Cd- or Zn-only treatment.
Zn-(0-1.6)Mg (in wt.%) alloys were prepared by hot extrusion at 300 °C. The structure, mechanical properties and in vitro biocompatibility of the alloys were investigated. The hot-extruded magnesium-based WE43 alloy was used as a control. Mechanical properties were evaluated by hardness, compressive and tensile testing. The cytotoxicity, genotoxicity (comet assay) and mutagenicity (Ames test) of the alloy extracts and ZnCl2 solutions were evaluated with the use of murine fibroblasts L929 and human osteosarcoma cell line U-2 OS. The microstructure of the Zn alloys consisted of recrystallized Zn grains of 12 μm in size and fine Mg2Zn11 particles arranged parallel to the hot extrusion direction. Mechanical tests revealed that the hardness and strength increased with increasing Mg concentration. The Zn-0.8 Mg alloys showed the best combination of tensile mechanical properties (tensile yield strength of 203 MPa, ultimate tensile strength of 301 MPa and elongation of 15%). At higher Mg concentrations the plasticity of Zn-Mg alloys was deteriorated. Cytotoxicity tests with alloy extracts and ZnCl2 solutions proved the maximum safe Zn(2+) concentrations of 120 μM and 80 μM for the U-2 OS and L929 cell lines, respectively. Ames test with extracts of alloys indicated that the extracts were not mutagenic. The comet assay demonstrated that 1-day extracts of alloys were not genotoxic for U-2 OS and L929 cell lines after 1-day incubation.
- MeSH
- biokompatibilní materiály chemie toxicita MeSH
- hořčík chemie toxicita MeSH
- kultivované buňky MeSH
- lidé MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- poškození DNA účinky léků MeSH
- slitiny chemie toxicita MeSH
- viabilita buněk účinky léků MeSH
- zinek chemie toxicita MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The present review deals with the harmful effects of mineral oils used as protective layers in fertilization in vitro. The results have shown the importance of the high quality and purity of the mineral oils used for the purpose. Contaminants reducing the oil quality include peroxides, Zn and Triton X-100. The review also highlights the deleterious effects of UV radiation on the oil which are usually less considered. Further the importance of storage and transportation for maintaining a high-quality oil is emphasized.
- MeSH
- biotechnologie metody MeSH
- časosběrné zobrazování MeSH
- embryo savčí MeSH
- embryonální vývoj MeSH
- fertilizace in vitro * MeSH
- implantace embrya MeSH
- kultivační média * MeSH
- lidé MeSH
- minerální olej * aplikace a dávkování chemie škodlivé účinky MeSH
- peroxidy toxicita MeSH
- povrchově aktivní látky toxicita MeSH
- ultrafialové záření škodlivé účinky MeSH
- zinek toxicita MeSH
- zohlednění rizika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
The essential requirement for the effective phytoremediation is selection of a plant species which should be metal tolerant, with high biomass production and known agronomic techniques. The above mentioned criteria are met by crop plant sorghum (Sorghum bicolor). The response of hydroponically grown S. bicolor plants to cadmium and zinc stress was followed. The impact of metal application on physiological parameters, including changes in chlorophylls contents and antioxidative enzymes activities, was followed during the stress progression. Cadmium and zinc were accumulated primarily in the roots of sorghum plants. However, elevation of metal concentrations in the media promoted their transfer to the shoots. Toxic effects of metals applied at lower concentrations were less serious in the shoots in comparison with their influence to the roots. When applied at higher concentrations, transfer of the metals into the leaves increased, causing growth reduction and leading to Chl loss and metal-induced chlorosis. Moreover, higher metal levels in the roots overcame the quenching capacity of peroxidase and glutathione transferase, which was associated with reduction of their activities. Fortification of antioxidant system by addition of glutathione significantly increased the accumulation of cadmium in the roots as well as in the shoots at the highest cadmium concentration applied.
- MeSH
- biodegradace MeSH
- biomasa MeSH
- glutathion metabolismus MeSH
- kadmium metabolismus toxicita MeSH
- kořeny rostlin enzymologie růst a vývoj metabolismus MeSH
- listy rostlin enzymologie růst a vývoj metabolismus MeSH
- peroxidasy metabolismus MeSH
- Sorghum enzymologie růst a vývoj metabolismus MeSH
- zinek metabolismus toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Increased endogenous plant cytokinin (CK) content through transformation with an isopentyl transferase (ipt) gene has been associated with improved plant stress tolerance. The objective of this study is to determine amino acid changes associated with elevated CK production in ipt transgenic tobacco (Nicotiana tabacum L., cv. Wisconsin 38). Nontransformed (WT) and transformed tobacco plants with ipt gene controlled by senescence-activated promoter (SAG) were exposed to zinc soil contamination (tested levels Zn1=250, Zn2=500, Zn3=750 mg kg(-1) soil). The Zn effect on plant stress metabolism resulted in changes in levels of selected free amino acids playing an important role in adaptation to stress and plant senescence (alanine, leucine, proline, methionine and γ-aminobutyrate) and differed for transformed and nontransformed tobacco plants. Analyses of amino acids confirmed that SAG tobacco plants had improved zinc tolerance compared with the WT plants. The enhanced Zn tolerance of SAG plants was associated with the maintenance of accumulation of proline, methionine and γ-aminobutyrate. The concentrations of leucine and alanine did not show significant differences between plant lines.
- MeSH
- aminokyseliny analýza metabolismus MeSH
- čas MeSH
- cytokininy genetika metabolismus MeSH
- fyziologická adaptace účinky léků MeSH
- geneticky modifikované rostliny genetika metabolismus MeSH
- látky znečišťující půdu toxicita MeSH
- promotorové oblasti (genetika) MeSH
- tabák genetika metabolismus fyziologie MeSH
- zinek toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Increased endogenous plant cytokinin (CK) content through transformation with an isopentyl transferase (ipt) gene has been associated with improved plant stress tolerance. The impact of zinc (tested levels Zn1=250, Zn2=500, Zn3=750mgkg(-1)soil) on gas exchange parameters (net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration) and nitrogen utilization by plants resulted in changes of free amino acid concentrations (glutamic acid, glutamine, asparagine, aspartate, glycine, serine, cystein) and differed for transformed and non-transformed tobacco plants. For pot experiments, tobacco plants (Nicotiana tabacum L., cv. Wisconsin 38) transformed with a construct consisting of SAG12 promoter fused with the ipt gene for cytokinin synthesis (SAG plants) and its wild type (WT plants as a control) were used. Physiological analyses confirmed that SAG plants had improved zinc tolerance compared with the WT plants. The enhanced Zn tolerance of SAG plants was associated with the maintenance of accumulation of amino acids and with lower declines of photosynthetic and transpiration rates. In comparison to WT plants, SAG plants exposed to the highest Zn concentration accumulated lower concentrations of asparagine, which is a major metabolic product during senescence.
- MeSH
- aminokyseliny metabolismus MeSH
- cytokininy metabolismus MeSH
- dusík metabolismus MeSH
- fotosyntéza účinky léků MeSH
- geneticky modifikované rostliny účinky léků genetika metabolismus MeSH
- promotorové oblasti (genetika) MeSH
- regulace genové exprese u rostlin účinky léků MeSH
- rostlinné proteiny genetika metabolismus MeSH
- tabák účinky léků genetika metabolismus MeSH
- zinek toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Metal-related genes (afe_0654, afe_0671, afe_0674, afe_1143, afe_1144, and afe_2126) were cloned to identify whether those genes existed in Acidithiobacillus ferrooxidans strain DC (A. ferrooxidans DC). The deduced amino acid sequences of those genes were analyzed by bioinformatics. The tolerance levels of A. ferrooxidans DC to Mn(2+), Zn(2+), and Cd(2+) were determined, which were 0.52, 0.42, and 0.16 mol/L for ferrous iron-grown cells and 0.38, 0.18, and 0.08 mol/L for sulfur-grown cells, respectively. Real-time quantitative PCR was employed to analyze the transcriptional levels of the metal-related genes when ferrous iron- and sulfur-grown cells of A. ferrooxidans DC, respectively, exposed to Mn(2+), Zn(2+), and Cd(2+). The metal-related genes were up-regulated when A. ferrooxidans DC exposed to Mn(2+). When A. ferrooxidans DC exposed to Zn(2+), the metal-related genes were up-regulated in sulfur-grown cells; afe_0654 and afe_0674 were down-regulated, and the others were up-regulated in ferrous iron-grown cells. Afe_2126 was down-regulated, and the others were up-regulated when A. ferrooxidans DC exposed to Cd(2+). According to experimental results and bioinformatics analysis, the proteins encoded by afe_0654 and afe_0674 may relate with Mn(2+) and Cd(2+) efflux. It needed further study whether they relate with Zn(2+) transport. Proteins encoded by afe_0671, afe_1143, and afe_1144 may relate with the efflux of Mn(2+), Zn(2+), and Cd(2+). The protein encoded by afe_2126 may relate with Mn(2+) and Zn(2+) efflux and Cd(2+) uptake.
- MeSH
- Acidithiobacillus účinky léků genetika růst a vývoj MeSH
- bakteriální geny MeSH
- bakteriální proteiny genetika metabolismus MeSH
- biologický transport MeSH
- hořčík metabolismus toxicita MeSH
- klonování DNA MeSH
- kovy metabolismus toxicita MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- mangan metabolismus toxicita MeSH
- mikrobiální testy citlivosti MeSH
- regulace genové exprese u bakterií účinky léků MeSH
- sekvenční analýza DNA MeSH
- síra metabolismus MeSH
- stanovení celkové genové exprese MeSH
- výpočetní biologie MeSH
- zinek metabolismus toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In short-term laboratory tests, changes in Cd, Zn and plant pigment (chlorophyll a, chlorophyll b and carotenoids) contents in leaves of sunflower grown under Cd and Zn stress conditions were investigated. CdCl2 and Zn acetate solutions were applied in the amounts 20 mg Cd or Zn per kg of soil. The presence of Cd or Zn lowered the contents of chlorophylls a and b by 6 % or 9.2 %, respectively. Statistically significant reduction of both chlorophylls and carotenoids was observed in the treatment with Cd and Zn. Total chlorophyll and carotenoids contents decreased in the order: Cd and Zn > Cd > Zn. A statistically significant increase in the Cd content of 17.2 % and reduction in the Zn content of 17.2 % were observed by application of Cd and Zn (1:1).
