Toxicity of lanthanides is generally regarded as low, and they even have been suggested to be beneficial at low concentrations. This research was conducted to investigate effects of Lanthanum (La) on Desmodesmus quadricauda, a freshwater green microalga. The algal cultures were treated with nanomolar La concentrations under controlled environmentally relevant conditions. Intracellular localization of La was analyzed with μXRF tomography in frozen-hydrated samples. At sublethal concentration (128 nM) La was in hotspots inside the cells, while at lethal 1387 nM that led to release of other ions (K, Zn) from the cells, La filled most of the cells. La had no clear positive effects on growth or photosynthetic parameters, but increasing concentrations led to a dramatic decrease in cell counts. Chlorophyll fluorescence kinetic measurements showed that La led to the inhibition of photosynthesis. Maximal photochemical quantum yield of the PSII reaction center in dark-adapted state (Fv/Fm) decreased at > 4.3 nM La during the 2nd week of treatment. Minimum dark-adapted fluorescence quantum yield (F0) increased at > 13.5 nM La during the 2nd week of treatment except for control (0.2 nM La, baseline from chemicals) and 0.3 nM La. NPQ at the beginning of the actinic light phase showed significant increase for all the treatments. Metalloproteomics by HPLC-ICPMS showed that La binds to a >500 kDa soluble protein complex already in the sub-nM range of La treatments, in the low nM range to a small-sized (3 kDa) soluble peptide, and at >100 nM La additionally binds to a 1.5 kDa ligand.
- MeSH
- chemické látky znečišťující vodu toxicita MeSH
- chlorofyl metabolismus MeSH
- Chlorophyta účinky léků fyziologie MeSH
- fluorescence MeSH
- fotosyntéza účinky léků MeSH
- fotosystém II - proteinový komplex účinky léků metabolismus MeSH
- lanthan metabolismus toxicita MeSH
- listy rostlin metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Alterations of hydrogen peroxide (H2O2) levels have a profound impact on numerous signaling cascades orchestrating plant growth, development, and stress signaling, including programmed cell death. To expand the repertoire of known molecular mechanisms implicated in H2O2 signaling, we performed a forward chemical screen to identify small molecules that could alleviate the photorespiratory-induced cell death phenotype of Arabidopsisthaliana mutants lacking H2O2-scavenging capacity by peroxisomal catalase2. Here, we report the characterization of pakerine, an m-sulfamoyl benzamide from the sulfonamide family. Pakerine alleviates the cell death phenotype of cat2 mutants exposed to photorespiration-promoting conditions and delays dark-induced senescence in wild-type Arabidopsis leaves. By using a combination of transcriptomics, metabolomics, and affinity purification, we identified abnormal inflorescence meristem 1 (AIM1) as a putative protein target of pakerine. AIM1 is a 3-hydroxyacyl-CoA dehydrogenase involved in fatty acid β-oxidation that contributes to jasmonic acid (JA) and salicylic acid (SA) biosynthesis. Whereas intact JA biosynthesis was not required for pakerine bioactivity, our results point toward a role for β-oxidation-dependent SA production in the execution of H2O2-mediated cell death.
- MeSH
- Arabidopsis cytologie účinky léků genetika metabolismus MeSH
- buněčná smrt účinky léků MeSH
- buněčné dýchání účinky léků genetika MeSH
- cyklopentany metabolismus MeSH
- fotosyntéza účinky léků genetika MeSH
- fyziologický stres MeSH
- hydroponie metody MeSH
- kyselina salicylová metabolismus MeSH
- listy rostlin cytologie účinky léků metabolismus MeSH
- meristém cytologie účinky léků metabolismus MeSH
- multienzymové komplexy genetika metabolismus MeSH
- oxylipiny metabolismus MeSH
- peroxid vodíku antagonisté a inhibitory farmakologie MeSH
- proteiny huseníčku genetika metabolismus MeSH
- regulace genové exprese u rostlin * MeSH
- rostlinné buňky účinky léků metabolismus MeSH
- semena rostlinná účinky léků MeSH
- signální transdukce MeSH
- stanovení celkové genové exprese MeSH
- sulfonamidy chemická syntéza farmakologie MeSH
- transkriptom MeSH
- výpočetní biologie metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Given the close relationship between cytokinins (CKs), photosynthesis and nitrogen metabolism, this study assessed the effect of arsenic (As) contamination on these metabolic components in the As-hyperaccumulators Pteris cretica L. var. Albo-lineata (Pc-A) and var. Parkerii (Pc-P) as well as the As-non-hyperaccumulator Pteris straminea Mett. ex Baker (Ps). The ferns were cultivated in a pot experiment for 23 weeks in soil spiked with As at the levels 20 and 100 mg·kg-1. For the purpose of this study, the CKs were placed into five functionally different groups according to their structure and physiological roles: bioactive forms (bCKs; CK free bases); inactive or weakly active forms (dCKs; CK N-glucosides); transport forms (tCKs; CK ribosides); storage forms (sCKs; O-glucosides); and primary products of CK biosynthesis (ppbCKs; CK nucleotides). An important finding was higher CKs total content, accumulation of sCKs and reduction of dCKs in As-hyperaccumulators in contrast to non-hyperaccumulator ferns. A significant depletion of C resources was confirmed in ferns, especially Ps, which was determined by measuring the photosynthetic rate and chlorophyll fluorescence. A fluorescence decrease signified a reduction in the C/N ratio, inducing an increase of bioactive CKs forms in Pc-P and Ps. The impact of As on N utilization was significant in As-hyperaccumulators. The glutamic acid/glutamine ratio, an indicator of primary N assimilation, diminished in all ferns with increased As level in the soil. In conclusion, the results indicate a large phenotypic diversity of Pteris species to As and suggest that the CKs composition and the glutamic acid/glutamine ratio can be used as a tool to diagnose As stress in plants.
- MeSH
- aminokyseliny metabolismus MeSH
- arsen toxicita MeSH
- biomasa MeSH
- cytokininy metabolismus MeSH
- dusík metabolismus MeSH
- fotosyntéza účinky léků MeSH
- látky znečišťující půdu toxicita MeSH
- listy rostlin účinky léků růst a vývoj metabolismus MeSH
- Pteris účinky léků růst a vývoj metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Arsenic toxicity induces a range of metabolic responses in plants, including DNA methylation. The focus of this paper was on the relationship between As-induced stress and plant senescence in the hyperaccumulator Pteris cretica var. Albo-lineata (Pc-Al). We assume difference in physiological parameters and level of DNA methylation in young and old fronds as symptoms of As toxicity. RESULTS: The As accumulation of Pc-Al fronds, grown in pots of haplic chernozem contaminated with 100 mg As kg- 1 for 122 days, decreased with age. Content of As was higher in young than old fronds for variants with 100 mg As kg- 1 (2800 and 2000 mg As kg- 1 dry matter, respectively). The highest As content was determined in old fronds of Pc-Al grown in pots with 250 mg As kg- 1. The increase with age was confirmed for determined nutrients - Cu, Mg, Mn, S and Zn. A significant elevation of all analysed nutrients was showed in old fronds. Arsenic accumulation affected DNA methylation status in fronds, but content of 5-methylcytosine (5mC) decreased only in old fronds of Pc-Al (from 25 to 12%). Determined photosynthetic processes showed a decrease of fluorescence, photosynthetic rate and chlorophylls of As treatments in young and old fronds. Water potential was decreased by As in both fronds. Thinning of the sclerenchymatous inner cortex and a reduction in average tracheid metaxylem in the vascular cylinder was showed in roots of As treatment. Irrespective to fronds age, physiological parameters positively correlated with a 5mC while negatively with direct As toxicity. Opposite results were found for contents of Cu, Mg, Mn, S and Zn. CONCLUSIONS: The results of this paper point to changes in the metabolism of the hyperaccumulator plant Pc-Al, upon low and high exposure to As contamination. The significant impact of As on DNA methylation was found in old fronds. Irrespective to fronds age, significant correlations were confirmed for 5mC and As toxicity. Our analysis of the very low water potential values and lignification of cell walls in roots showed that transports of assimilated metabolites and water between roots and fronds were reduced. As was showed by our results, epigenetic changes could affect studied parameters of the As hyperaccumulator plant Pc-Al, especially in old fronds.
- MeSH
- 5-methylcytosin metabolismus MeSH
- arsen metabolismus toxicita MeSH
- chlorofyl metabolismus MeSH
- ekotoxikologie MeSH
- fotosyntéza účinky léků MeSH
- kořeny rostlin metabolismus MeSH
- látky znečišťující půdu metabolismus MeSH
- listy rostlin metabolismus MeSH
- metylace DNA účinky léků MeSH
- poškození DNA * účinky léků MeSH
- Pteris metabolismus MeSH
- živiny metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Early stages of ontogenesis determining subsequent growth, development, and productivity of crops can be affected by wastewater and sludge contaminated with pharmaceuticals. Diclofenac (DCF) and paracetamol (PCT; both 0.0001 to 10 mg/L) did not affect seed germination and primary root length of onion, lettuce, pea, and tomato. Conversely, 20-day-old pea and maize plants exhibited decrease in biomass production, leaf area (by approx. 40% in pea and 70% in maize under 10 mg/L DCF), or content of photosynthetic pigments (by 10% and 60% under 10 mg/L PCT). Quantum yields of photosystem II were reduced only in maize (FV/FM and ΦII by more than 40% under 10 mg/L of both pharmaceuticals). Contents of H2O2 and superoxide increased in roots of both species (more than four times under 10 mg/L PCT in pea). Activities of antioxidant enzymes were elevated in pea under DCF treatments, but decreased in maize under both pharmaceuticals. Oxidative injury of root cells expressed as lowered oxidoreductase activity (MTT assay, by 40% in pea and 80% in maize) and increase in malondialdehyde content (by 60% and 100%) together with the membrane integrity disruption (higher Evans Blue accumulation, by 100% in pea and 300% in maize) confirmed higher sensitivity of maize as a C4 monocot plant to both pharmaceuticals.
- MeSH
- antioxidancia analýza MeSH
- chemické látky znečišťující vodu toxicita MeSH
- diklofenak analýza toxicita MeSH
- fotosyntéza účinky léků MeSH
- klíčení účinky léků MeSH
- kořeny rostlin účinky léků metabolismus MeSH
- listy rostlin účinky léků MeSH
- malondialdehyd analýza MeSH
- odpadní voda chemie MeSH
- paracetamol analýza toxicita MeSH
- peroxid vodíku analýza metabolismus MeSH
- semena rostlinná účinky léků fyziologie MeSH
- zemědělské plodiny účinky léků růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
A series of twenty-six methoxylated and methylated N-aryl-1-hydroxynaphthalene- 2-carboxanilides was prepared and characterized as potential anti-invasive agents. The molecular structure of N-(2,5-dimethylphenyl)-1-hydroxynaphthalene-2-carboxamide as a model compound was determined by single-crystal X-ray diffraction. All the analysed compounds were tested against the reference strain Staphylococcus aureus and three clinical isolates of methicillin-resistant S.aureus as well as against Mycobacterium tuberculosis and M. kansasii. In addition, the inhibitory profile of photosynthetic electron transport in spinach (Spinacia oleracea L.) chloroplasts was specified. In vitro cytotoxicity of the most effective compounds was tested on the human monocytic leukaemia THP-1 cell line. The activities of N-(3,5-dimethylphenyl)-, N-(3-fluoro-5-methoxy-phenyl)- and N-(3,5-dimethoxyphenyl)-1-hydroxynaphthalene-2-carbox- amide were comparable with or even better than the commonly used standards ampicillin and isoniazid. All promising compounds did not show any cytotoxic effect at the concentration >30 µM. Moreover, an in silico evaluation of clogP features was performed for the entire set of the carboxamides using a range of software lipophilicity predictors, and cross-comparison with the experimentally determined lipophilicity (log k), in consensus lipophilicity estimation, was conducted as well. Principal component analysis was employed to illustrate noticeable variations with respect to the molecular lipophilicity (theoretical/experimental) and rule-of-five violations. Additionally, ligand-oriented studies for the assessment of the three-dimensional quantitative structure-activity relationship profile were carried out with the comparative molecular surface analysis to determine electron and/or steric factors that potentially contribute to the biological activities of the investigated compounds.
- MeSH
- ampicilin farmakologie MeSH
- analýza hlavních komponent MeSH
- anilidy chemická syntéza chemie farmakologie MeSH
- antibakteriální látky chemická syntéza chemie farmakologie MeSH
- chloroplasty účinky léků fyziologie MeSH
- fotosyntéza účinky léků MeSH
- isoniazid farmakologie MeSH
- lidé MeSH
- methicilin rezistentní Staphylococcus aureus účinky léků růst a vývoj MeSH
- metylace MeSH
- mikrobiální testy citlivosti MeSH
- Mycobacterium kansasii účinky léků růst a vývoj MeSH
- Mycobacterium tuberculosis účinky léků růst a vývoj MeSH
- naftoly chemická syntéza chemie farmakologie MeSH
- Spinacia oleracea chemie účinky léků metabolismus MeSH
- THP-1 buňky MeSH
- transport elektronů účinky léků MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Microorganisms produce volatile compounds (VCs) that promote plant growth and photosynthesis through complex mechanisms involving cytokinin (CK) and abscisic acid (ABA). We hypothesized that plants' responses to microbial VCs involve posttranslational modifications of the thiol redox proteome through action of plastidial NADPH-dependent thioredoxin reductase C (NTRC), which regulates chloroplast redox status via its functional relationship with 2-Cys peroxiredoxins. To test this hypothesis, we analysed developmental, metabolic, hormonal, genetic, and redox proteomic responses of wild-type (WT) plants and a NTRC knockout mutant (ntrc) to VCs emitted by the phytopathogen Alternaria alternata. Fungal VC-promoted growth, changes in root architecture, shifts in expression of VC-responsive CK- and ABA-regulated genes, and increases in photosynthetic capacity were substantially weaker in ntrc plants than in WT plants. As in WT plants, fungal VCs strongly promoted growth, chlorophyll accumulation, and photosynthesis in ntrc-Δ2cp plants with reduced 2-Cys peroxiredoxin expression. OxiTRAQ-based quantitative and site-specific redox proteomic analyses revealed that VCs promote global reduction of the thiol redox proteome (especially of photosynthesis-related proteins) of WT leaves but its oxidation in ntrc leaves. Our findings show that NTRC is an important mediator of plant responses to microbial VCs through mechanisms involving global thiol redox proteome changes that affect photosynthesis.
- MeSH
- Alternaria * MeSH
- Arabidopsis účinky léků metabolismus MeSH
- cytokininy metabolismus MeSH
- fotosyntéza účinky léků MeSH
- kyselina abscisová metabolismus MeSH
- posttranslační úpravy proteinů účinky léků MeSH
- proteiny huseníčku metabolismus MeSH
- proteom MeSH
- těkavé organické sloučeniny farmakologie MeSH
- thioredoxin-disulfidreduktasa metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Mechanisms of pharmaceuticals action on biochemical and physiological processes in plants that determine plant growth and development are still mostly unknown. This study deals with the effects of non-steroidal anti-inflammatory drug diclofenac (DCF) on photosynthesis as an essential anabolic process. Changes in primary and secondary photosynthetic processes were assessed in chloroplasts isolated from Lemna minor exposed to 1, 10, 100, and 1000 μM DCF. Decreases in the potential and effective quantum yields of photosystem II (FV/FM by 21%, ΦII by 44% compared to control), changes in non-photochemical fluorescence quenching (NPQ), and a substantial drop in Hill reaction activity (by 73%), especially under 1000 μM DCF, were found. Limitation of electron transport through photosystem II was confirmed by increased fluorescence signals in steps J and I (by 50% and 23%, respectively, under 1000 μM DCF) in OJIP fluorescence transient. Photosystem I exhibited changes only in the redox state of P700 reaction centres (decrease in Pm by 10%, increase in reduced P700 by 5% under 1000 μM DCF). Similarly, RuBisCO activity was only lowered by 30% under 1000 μM DCF. In contrast, a significant increase in reactive oxygen and nitrogen species (by 116% and 157%, respectively) was observed under 10 μM DCF, and lipid peroxidation increased even at 1 μM DCF (by nearly seven times compared to the control). Results demonstrate the ability of environmentally relevant DCF concentrations to induce oxidative stress in isolated duckweed chloroplasts; however, photosynthetic processes were affected considerably only by the highest DCF treatments.
- MeSH
- Araceae účinky léků růst a vývoj ultrastruktura MeSH
- chloroplasty účinky léků metabolismus MeSH
- diklofenak farmakologie toxicita MeSH
- fotosyntéza účinky léků MeSH
- fotosystém I - proteinový komplex MeSH
- fotosystém II - proteinový komplex účinky léků metabolismus MeSH
- oxidační stres účinky léků MeSH
- peroxidace lipidů účinky léků MeSH
- transport elektronů účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
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.
MAIN CONCLUSION: This review provides insights into As toxicity in plants with focus on photosynthesis and sugar metabolism as important arsenic targets and simultaneously defence tools against accompanying oxidative stress. Heavy metal contamination is a great problem all over the world. Arsenic, a metalloid occurring naturally in the Earth's crust, also massively spreads out in the environment by human activities. Its accumulation in crops poses a severe health risk to humans and animals. Besides the restriction of human-caused contamination, there are two basic ways how to cope with the problem: first, to limit arsenic accumulation in harvestable parts of the crops; second, to make use of some arsenic hyperaccumulating plants for phytoremediation of contaminated soils and waters. Progress in the use of both strategies depends strongly on the level of our knowledge on the physiological and morphological processes resulting from arsenic exposure. Arsenic uptake is mediated preferentially by P and Si transporters and its accumulation substantially impairs plant metabolism at numerous levels including damages through oxidative stress. Rice is a predominantly studied crop where substantial progress has been made in understanding of the mechanisms of arsenic uptake, distribution, and detoxification, though many questions still remain. Full exploitation of plant potential for soil and water phytoremediations also requires deep understanding of the plant response to this toxic metalloid. The aim of this review is to summarize data regarding the effect of arsenic on plant physiology with a focus on mechanisms providing increased arsenic tolerance and/or hyperaccumulation. The emphasis is placed on the topic unjustifiably neglected in the previous reviews - i.e., carbohydrate metabolism, tightly connected to photosynthesis, and beside others involved in plant ability to cope with arsenic-induced oxidative and nitrosative stresses.
- MeSH
- arsen metabolismus toxicita MeSH
- biodegradace MeSH
- fotosyntéza účinky léků MeSH
- látky znečišťující půdu metabolismus toxicita MeSH
- metabolismus sacharidů účinky léků MeSH
- nitrosativní stres účinky léků MeSH
- zemědělské plodiny účinky léků metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
