Arsenic (As) contaminates the food chain and decreases agricultural production through impairing plants, particularly due to oxidative stress. To better understand the As tolerance mechanisms, two contrasting tobacco genotypes: As-sensitive Nicotiana sylvestris and As-tolerant N.tabacum, cv. 'Wisconsin' were analyzed. The most meaningful differences were found in the carbohydrate status, neglected so far in the As context. In the tolerant genotype, contrary to the sensitive one, net photosynthesis rates and saccharide levels were unaffected by As exposure. Importantly, the total antioxidant capacity was far stronger in the As-tolerant genotype, based on higher antioxidants levels (e.g., phenolics, ascorbate, glutathione) and activities and/or appropriate localizations of antioxidative enzymes, manifested as reverse root/shoot activities in the selected genotypes. Accordingly, malondialdehyde levels, a lipid peroxidation marker, increased only in sensitive tobacco, indicating efficient membrane protection in As-tolerant species. We bring new evidence of the orchestrated action of a broad spectrum of both antioxidant enzymes and molecules essential for As stress coping. For the first time, we propose robust carbohydrate metabolism based on undisturbed photosynthesis to be crucial not only for subsidizing C and energy for defense but also for participating in direct reactive oxygen species (ROS) quenching. The collected data and suggestions can serve as a basis for the selection of plant As phytoremediators or for targeted breeding of tolerant crops.
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Strigolactones are a unique class of plant metabolites which serve as a rhizosphere signal for parasitic plants and evocate their seed germination. The expansion of these parasitic weeds in the food crop fields urgently calls for their increased control and depletion. Simple strigolactone analogues able to stimulate seed germination of these parasitic plants may represent an efficient control measure through the induction of suicidal germination. RESULTS: Triazolide-type strigolactone mimics were easily synthesized in three steps from commercially available materials. These derivatives induced effectively seed germination of Phelipanche ramosa with EC50 as low as 5.2 × 10-10 M. These mimics did not induce seed germination of Striga hermonthica even at high concentration (≥1 × 10-5 M). CONCLUSIONS: Simple and stable strigolactone mimics with selective activity against Phelipanche ramosa were synthesized. © 2019 Society of Chemical Industry.
Engineered nanoparticles (ENPs) exhibit unique properties advantageous in a number of applications, but they also represent potential health and environmental risks. In this study, we investigated the phytotoxic mechanism of CuO ENPs using transcriptomic analysis and compared this response with the response to CuO bulk particles and ionic Cu2+. Ionic Cu2+at the concentration of 0.16 mg L-1changed transcription of 2692 genes (p value of <0.001, fold change of ≥2) after 7 days of exposure, whereas CuO ENPs and bulk particles (both in the concentration of 10 mg L-1) altered the expression of 922 and 482 genes in Arabidopsis thaliana roots, respectively. The similarity between transcription profiles of plants exposed to ENPs and ionic Cu2+indicated that the main factor in phytotoxicity was the release of Cu2+ions from CuO ENPs after 7 days of exposure. The effect of Cu2+ions was evident in all treatments, as indicated by the down-regulation of genes involved in metal homeostasis and transport and the up-regulation of oxidative stress response genes. ENPs were more soluble than bulk particles, resulting in the up-regulation of metallochaperone-like genes or the down-regulation of aquaporins and metal transmembrane transporters that was also characteristic for ionic Cu2+exposure.
Pro všední den, ISSN 2464-6245 64
Vydání 1. 23 stran : barevné ilustrace ; 21 cm
V průběhu let se fytoremediace ukázala jako platná metoda pro snižování kontaminace životního prostředí přírodě blízkými postupy a k úspoře spotřeby stále více nedostatkové vody. Je zároveň ilustrativním příkladem toho, jak základní výzkum prováděný v laboratoři může v relativně krátkém čase přispět k řešení celospolečenských problémů.
- MeSH
- biodegradace MeSH
- regenerace a remediace životního prostředí MeSH
- rostliny MeSH
- věda MeSH
- výzkum MeSH
- Publikační typ
- monografie MeSH
Heavy metal soil contamination from mining and smelting has been reported in several regions around the world, and phytoextraction, using plants to accumulate risk elements in aboveground harvestable organs, is a useful method of substantially reducing this contamination. In our 3-year experiment, we tested the hypothesis that phytoextraction can be successful in local soil conditions without external fertilizer input. The phytoextraction efficiency of 15 high-yielding crop species was assessed in a field experiment performed at the Litavka River alluvium in the Příbram region of Czechia. This area is heavily polluted by Cd, Zn, and Pb from smelter installations which also polluted the river water and flood sediments. Heavy metal concentrations were analyzed in the herbaceous plants' aboveground and belowground biomass and in woody plants' leaves and branches. The highest Cd and Zn mean concentrations in the aboveground biomass were recorded in Salix x fragilis L. (10.14 and 343 mg kg-1 in twigs and 16.74 and 1188 mg kg-1 in leaves, respectively). The heavy metal content in woody plants was significantly higher in leaves than in twigs. In addition, Malva verticillata L. had the highest Cd, Pb, and Zn concentrations in herbaceous species (6.26, 12.44, and 207 mg kg-1, respectively). The calculated heavy metal removal capacities in this study proved high phytoextraction efficiency in woody species; especially for Salix × fragilis L. In other tested plants, Sorghum bicolor L., Helianthus tuberosus L., Miscanthus sinensis Andersson, and Phalaris arundinacea L. species are also recommended for phytoextraction.
Fire is a common cause of damage to people and property. The fires also cause a wide variety of acute and chronic pollution due to acid gases and persistent organic chemicals. Flame retardants are highly required chemicals that improve thermal resistance of materials. Main types of fire retardants used in polymers are phosphines, phosphonates, phosphates, silanes, siloxanes, boric acid, borates, carboranes, melamine derivatives, Al and Mg hydroxides as well as nanomaterials. Generally used halogenated flame retardants are characterized by high efficiency but, due to their toxicity and bioaccumulation, are of limited use. Currently are preferred combinations of N flame retardants and P compound. Nanomaterials seem prospective in future.
- MeSH
- halogeny škodlivé účinky toxicita MeSH
- nanostruktury MeSH
- retardanty hoření * klasifikace škodlivé účinky toxicita MeSH
- sloučeniny dusíku MeSH
- sloučeniny fosforu MeSH
- vystavení vlivu životního prostředí MeSH
- znečištění životního prostředí * prevence a kontrola MeSH
- Publikační typ
- práce podpořená grantem MeSH
The impact of nanosize was evaluated by comparing of the transcriptomic response of Arabidopsis thaliana roots to ZnO nanoparticles (nZnO), bulk ZnO, and ionic Zn(2+). Microarray analyses revealed 416 up- and 961 down-regulated transcripts (expression difference >2-fold, p [FDR] < 0.01) after a seven-day treatment with nZnO (average particle size 20 nm, concentration 4 mg L(-1)). Exposure to bulk ZnO resulted in 816 up- and 2179 down-regulated transcripts. The most dramatic changes (1711 transcripts up- and 3242 down-regulated) were caused by the presence of ionic Zn(2+) (applied as ZnSO4.7H20 at a concentration of 14.14 mg L(-1), corresponding to the amount of Zn contained in 4 mg L(-1) ZnO). Genes involved in stress response (e.g., to salt, osmotic stress or water deprivation) were the most relatively abundant group of gene transcripts up-regulated by all three Zn treatments while genes involved in cell organization and biogenesis (e.g., tubulins, arabinogalactan proteins) and DNA or RNA metabolism (e.g., histones) were the most relatively abundant groups of down-regulated transcripts. The similarity of the transcription profiles and the increasing number of changed transcripts correlating with the increased concentration of Zn(2+) in cultivation medium indicated that released Zn(2+) may substantially contribute to the toxic effect of nZnO because particle size has not demonstrated a decisive role.
- MeSH
- Arabidopsis účinky léků genetika MeSH
- kationty dvojmocné MeSH
- kořeny rostlin účinky léků genetika MeSH
- nanočástice chemie toxicita MeSH
- oxid zinečnatý chemie farmakologie toxicita MeSH
- síran zinečnatý chemie toxicita MeSH
- stanovení celkové genové exprese metody MeSH
- testy toxicity MeSH
- velikost částic MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie 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
The ability of thorium uptake as well as responses to heavy metal stress were tested in tobacco cultivar La Burley 21. Thorium was accumulated preferentially in the root system. The presence of citric, tartaric and oxalic acids in hydroponic medium increased thorium accumulation in all plant organs. On the other hand, the addition of diamines and polyamines, the important antioxidants in plants, resulted in decrease of thorium accumulation, especially in the root system. Negative correlation was found between putrescine concentration and thorium accumulation. Nevertheless, the most important factor influencing the accumulation of thorium was the absence of phosphate ions in a hydroponic medium that caused more than 10-fold increase of thorium uptake in all plant parts. Accumulation and distribution of thorium was followed in six cultivars and 14 selected transformants. Cultivar La Barley 21 represented an average between the tested genotypes, having a very good distribution ratio between roots, stems and leaves.
- MeSH
- diaminy chemie farmakologie MeSH
- fosfáty chemie nedostatek MeSH
- genotyp MeSH
- hydroponie MeSH
- ionty chemie MeSH
- kořeny rostlin účinky léků metabolismus MeSH
- listy rostlin účinky léků metabolismus MeSH
- polyaminy chemie farmakologie MeSH
- putrescin chemie farmakologie MeSH
- stonky rostlin účinky léků metabolismus MeSH
- tabák metabolismus MeSH
- thorium chemie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC(50) value about 0.1mM. Cucumis sativa represented the most resistant plant to uranium (EC(50)=0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1mM or 0.5mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation.
- MeSH
- autoradiografie MeSH
- biodegradace MeSH
- druhová specificita MeSH
- hydroponie MeSH
- kořeny rostlin růst a vývoj metabolismus MeSH
- Magnoliopsida růst a vývoj metabolismus MeSH
- radioaktivní látky znečišťující půdu metabolismus toxicita MeSH
- uran metabolismus toxicita MeSH
- zemědělské plodiny růst a vývoj metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
