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Результаты 1-10 из 72
The experimental phytotoxicology of germanium in relation to silicon.
1990
Puerner N.J. | Siegel S.M. | Siegel B.Z.
Effects of treatment agents during acid washing and pH neutralization on the fertility of heavy metal-impacted dredged marine sediment as plant-growing soil Полный текст
2020
Kim, Kibeum | Yoon, Sangwon | Kwon, Hyun-ah | Choi, Yongju
The present study was aimed at investigating the effects of different acids and pH neutralizers applied to dredged marine sediment for the treatment of heavy metals, and the resulting influence on the sediment quality as a plant growth medium. The inspection of barley germination in the dredged marine sediment revealed that residual salts are critical plant stressors whose adverse effects exceed those exhibited by high-level heavy metals and petroleum hydrocarbons present in the sediment. Acid washing and pH neutralization reduced not only the heavy metal contents but also the sediment salinity (by factors of 6.1–9.5), resulting in 100% germination of barley. For acid-washed and calcium-oxide-neutralized sediment, the barley growth was comparable to that observed in untreated and water washed sediment despite factors of 5.2–8.0 greater sediment salinity in the former. This result represents the protective effect of residual calcium against sodium and chloride toxicity. Water washing of acid-washed and pH-neutralized sediments further enhanced barley growth owing to the reduction in osmotic pressure. This study showed the effect of different sediment-washing reagents on the product quality. It also indicated the significance of balancing the enhancement of product quality and economic cost of further treatment requirements.
Показать больше [+] Меньше [-]Development and comparison of regression models for the uptake of metals into various field crops Полный текст
2015
Novotná, Markéta | Mikeš, Ondřej | Komprdová, Klára
Field crops represent one of the highest contributions to dietary metal exposure. The aim of this study was to develop specific regression models for the uptake of metals into various field crops and to compare the usability of other available models. We analysed samples of potato, hop, maize, barley, wheat, rape seed, and grass from 66 agricultural sites. The influence of measured soil concentrations and soil factors (pH, organic carbon, content of silt and clay) on the plant concentrations of Cd, Cr, Cu, Mo, Ni, Pb and Zn was evaluated. Bioconcentration factors (BCF) and plant-specific metal models (PSMM) developed from multivariate regressions were calculated. The explained variability of the models was from 19 to 64% and correlations between measured and predicted concentrations were between 0.43 and 0.90. The developed hop and rapeseed models are new in this field. Available models from literature showed inaccurate results, except for Cd; the modelling efficiency was mostly around zero. The use of interaction terms between parameters can significantly improve plant-specific models.
Показать больше [+] Меньше [-]Plant growth responses to inorganic environmental contaminants are density-dependent: Experiments with copper sulfate, barley and lettuce Полный текст
2014
Hansi, Mari | Weidenhamer, Jeffrey D. | Sinkkonen, Aki
The density-dependence of terrestrial plant–plant interactions in the presence of toxins has previously been explored using biodegradable compounds. We exposed barley and lettuce to four copper concentrations at four stand densities. We hypothesized that toxin effects would decrease and Cu uptake would increase at increasing plant densities. We analyzed toxin effects by (a) comparing plant biomasses and (b) using a recent regression model that has a separate parameter for the interaction of resource competition and toxin interference. Plant response to Cu was density-dependent in both experiments. Total Cu uptake by barley increased and the dose per plant decreased as plant density increased. This study is the first to demonstrate that plant density mediates plant response to metals in soil in a predictable way. This highlights the need to explore the mechanisms for and consequences of these effects, and to integrate the use of several plant densities into standard ecotoxicological testing.
Показать больше [+] Меньше [-]Lead phytotoxicity in soils and nutrient solutions is related to lead induced phosphorus deficiency Полный текст
2012
Cheyns, Karlien | Peeters, Sofie | Delcourt, Dorien | Smolders, Erik
This study was set up to relate lead (Pb) bioavailability with its toxicity to plants in soils. Tomato and barley seedlings were grown in six different PbCl₂ spiked soils (pH: 4.7–7.4; eCEC: 4.2–41.7 cmolc/kg). Soils were leached and pH corrected after spiking to exclude confounding factors. Plant growth was halved at 1600–6500 mg Pb/kg soil for tomato and at 1900–8300 mg Pb/kg soil for barley. These soil Pb threshold were unrelated to soil pH, organic carbon, texture or eCEC and neither soil solution Pb nor Pb²⁺ ion activity adequately explained Pb toxicity among soils. Shoot phosphorus (P) concentrations significantly decreased with increasing soil Pb concentrations. Tomato grown in hydroponics at either varying P supply or at increasing Pb (equal initial P) illustrated that shoot P explained growth response in both scenarios. The results suggest that Pb toxicity is partially related to Pb induced P deficiency, likely due to lead phosphate precipitation.
Показать больше [+] Меньше [-]Lumbricus terrestris L. activity increases the availability of metals and their accumulation in maize and barley Полный текст
2011
Ruiz, E. | Alonso-Azcárate, J. | Rodriguez, L. (Luis)
The effect of the earthworm Lumbricus terrestris L. on metal availability in two mining soils was assessed by means of chemical extraction methods and a pot experiment using crop plants. Results from single and sequential extractions showed that L. terrestris had a slight effect on metal fractionation in the studied soils: only metals bound to the soil organic matter were significantly increased in some cases. However, we found that L. terrestris significantly increased root, shoot and total Pb and Zn concentrations in maize and barley for the soil with the highest concentrations of total and available metals. Specifically, shoot Pb concentration was increased by a factor of 7.5 and 3.9 for maize and barley, respectively, while shoot Zn concentration was increased by a factor of 3.7 and 1.7 for maize and barley, respectively. Our results demonstrated that earthworm activity increases the bioavailability of metals in soils.
Показать больше [+] Меньше [-]Development and validation of a terrestrial biotic ligand model predicting the effect of cobalt on root growth of barley (Hordeum vulgare) Полный текст
2007
Lock, K. | Schamphelaere, K.A.C de | Becaus, S. | Criel, P. | Eeckhout, H van | Janssen, C.R.
A Biotic Ligand Model was developed predicting the effect of cobalt on root growth of barley (Hordeum vulgare) in nutrient solutions. The extent to which Ca2+, Mg2+, Na+, K+ ions and pH independently affect cobalt toxicity to barley was studied. With increasing activities of Mg2+, and to a lesser extent also K+, the 4-d EC50Co2+ increased linearly, while Ca2+, Na+ and H+ activities did not affect Co2+ toxicity. Stability constants for the binding of Co2+, Mg2+ and K+ to the biotic ligand were obtained: log KCoBL = 5.14, log KMgBL = 3.86 and log KKBL = 2.50. Limited validation of the model with one standard artificial soil and one standard field soil showed that the 4-d EC50Co2+ could only be predicted within a factor of four from the observed values, indicating further refinement of the BLM is needed. Biotic Ligand Models are not only a useful tool to assess metal toxicity in aquatic systems but can also be used for terrestrial plants.
Показать больше [+] Меньше [-]Fate of microplastics in agricultural soils amended with sewage sludge: Is surface water runoff a relevant environmental pathway? Полный текст
2022
Schell, Theresa | Hurley, Rachel | Buenaventura, Nina T. | Mauri, Pedro V. | Nizzetto, Luca | Rico, Andreu | Vighi, M.
Fate of microplastics in agricultural soils amended with sewage sludge: Is surface water runoff a relevant environmental pathway? Полный текст
2022
Schell, Theresa | Hurley, Rachel | Buenaventura, Nina T. | Mauri, Pedro V. | Nizzetto, Luca | Rico, Andreu | Vighi, M.
Sewage sludge used as agricultural fertilizer has been identified as an important source of microplastics (MPs) to the environment. However, the fate of MPs added to agricultural soils is largely unknown. This study investigated the fate of MPs in agricultural soils amended with sewage sludge and the role of surface water runoff as a mechanism driving their transfer to aquatic ecosystems. This was assessed using three experimental plots located in a semi-arid area of Central Spain, which were planted with barley. The experimental plots received the following treatments: (1) control or no sludge application; (2) historical sludge application, five years prior to the experiment; and (3) sludge application at the beginning of the experiment. MPs were analyzed in surface water runoff and in different soil layers to investigate transport and infiltration for one year. The sewage sludge used in our experiment contained 5972–7771 MPs/kg dw. Based on this, we estimated that about 16,000 MPs were added to the agricultural plot amended with sludge. As expected, the sludge application significantly increased the MP concentration in soils. The control plot contained low MP concentrations (31–120 MPs kg⁻¹ dw), potentially originating from atmospheric deposition. The plot treated five years prior to the experiment contained 226–412 and 177–235 MPs kg⁻¹ dw at the start and end of the experiment, respectively; while the recently treated plot contained 182–231 and 138–288 MPs kg⁻¹ dw. Our study shows that MP concentrations remain relatively constant in agricultural soils and that the MP infiltration capacity is very low. Surface water runoff had a negligible influence on the export of MPs from agricultural soils, mobilizing only 0.2–0.4% of the MPs added with sludge. We conclude that, in semi-arid regions, agricultural soils can be considered as long-term accumulators of MPs.
Показать больше [+] Меньше [-]Fate of microplastics in agricultural soils amended with sewage sludge: Is surface water runoff a relevant environmental pathway? Полный текст
2022
Schell, Theresa | Hurley, Rachel | Buenaventura, Nina Tuscano | Mauri, Pedro V. | Nizzetto, Luca | Rico, Andreu | Vighi, Marco
Embargo until November 18, 2023 | Sewage sludge used as agricultural fertilizer has been identified as an important source of microplastics (MPs) to the environment. However, the fate of MPs added to agricultural soils is largely unknown. This study investigated the fate of MPs in agricultural soils amended with sewage sludge and the role of surface water runoff as a mechanism driving their transfer to aquatic ecosystems. This was assessed using three experimental plots located in a semi-arid area of Central Spain, which were planted with barley. The experimental plots received the following treatments: (1) control or no sludge application; (2) historical sludge application, five years prior to the experiment; and (3) sludge application at the beginning of the experiment. MPs were analyzed in surface water runoff and in different soil layers to investigate transport and infiltration for one year. The sewage sludge used in our experiment contained 5972–7771 MPs/kg dw. Based on this, we estimated that about 16,000 MPs were added to the agricultural plot amended with sludge. As expected, the sludge application significantly increased the MP concentration in soils. The control plot contained low MP concentrations (31–120 MPs kg−1 dw), potentially originating from atmospheric deposition. The plot treated five years prior to the experiment contained 226–412 and 177–235 MPs kg−1 dw at the start and end of the experiment, respectively; while the recently treated plot contained 182–231 and 138–288 MPs kg−1 dw. Our study shows that MP concentrations remain relatively constant in agricultural soils and that the MP infiltration capacity is very low. Surface water runoff had a negligible influence on the export of MPs from agricultural soils, mobilizing only 0.2–0.4% of the MPs added with sludge. We conclude that, in semi-arid regions, agricultural soils can be considered as long-term accumulators of MPs. | publishedVersion
Показать больше [+] Меньше [-]Strigolactone GR24 improves cadmium tolerance by regulating cadmium uptake, nitric oxide signaling and antioxidant metabolism in barley (Hordeum vulgare L.) Полный текст
2021
Qiu, Cheng-Wei | Zhang, Can | Wang, Nian-Hong | Mao, Weihua | Wu, Feibo
Cadmium (Cd) in the food chain poses a serious hazard to human health. Therefore, a greenhouse hydroponic experiment was conducted to examine the potential of exogenously strigolactone GR24 in lessening Cd toxicity and to investigate its physiological mechanisms in the two barley genotypes, W6nk2 (Cd-sensitive) and Zhenong8 (Cd-tolerant). Exogenous application of 1 μM GR24 (strigol analogue) reduced the suppression of growth caused by 10 μM Cd, lowered plant Cd contents, increased the contents of other nutrient elements, protected chlorophyll, sustained photosynthesis, and markedly reduced Cd-induced H₂O₂ and malondialdehyde accumulation in barley. Furthermore, exogenous GR24 markedly increased NO contents and nitric oxide synthase activity in the Cd-sensitive genotype, W6nk2, effectively alleviating the Cd-induced repression of the activities of superoxide dismutase and peroxidase, increasing reduced glutathione (GSH) and ascorbic acid (AsA) pools and activities of AsA-GSH cycle including ascorbate peroxidase, glutathione peroxidase, glutathione reductase, dehydroascorbate reductase and monodehydroascorbate reductase. The findings of the present study indicate that GR24 could be a candidate for Cd detoxification by decreasing Cd contents, balancing nutrient elements, and protecting barley plants from toxic oxidation via indirectly eliminating reactive oxygen species (ROS), consequently contributing to reducing the potential risk of Cd pollution.
Показать больше [+] Меньше [-]Uptake, translocation, and physiological effects of hematite (α-Fe2O3) nanoparticles in barley (Hordeum vulgare L.) Полный текст
2020
Tombuloglu, Huseyin | Slimani, Yassine | AlShammari, Thamer Marhoon | Bargouti, Muhammed | Ozdemir, Mehmet | Tombuloglu, Guzin | Ak̲h̲tar, Sult̤ān | Sabit, Hussain | Hakeem, Khalid Rehman | Almessiere, Munirah | Ercan, İsmail | Baykal, Abdulhadi
There has been a growing concern with the environmental influences of nanomaterials due to recent developments in nanotechnology. This study investigates the impact and fate of hematite nanoparticles (α-Fe₂O₃ NPs) (∼14 nm in size) on a crop species, barley (Hordeum vulgare L.). For this purpose, hematite NPs (50, 100, 200, and 400 mg/L) were hydroponically applied to barley at germination and seedling stages (three weeks). Inductively coupled plasma mass spectrophotometry (ICP-MS) along with vibrating sample magnetometer (VSM) techniques were used to track the NPs in plant tissues. The effects of NPs on the root cells were observed by scanning electron microscopy (SEM) and confocal microscopy. Results revealed that α-Fe₂O₃ NPs significantly reduced the germination rate (from 80% in control to 30% in 400 mg/L), as well as chlorophyll (36–39%) and carotenoid (37%) contents. Moreover, the treatment led to a significant decline in the quantum yield of photosystem II (Fv/Fm). Leaf VSM analysis indicated a change in magnetic signal for NPs-treated samples compared with untreated ones, which is mostly attributed to the iron (Fe) ions incorporated within the leaf tissue. Besides, Fe content in the roots and leaf had gradually increased by the increasing doses of NPs, which was confirming NPs’ translocation to the aerial parts. Microscopic observations revealed that α-Fe₂O₃ NPs altered root cell morphology and led to the injury of cell membranes. This study, in the light of our findings, shows that α-Fe₂O₃ NPs (∼14 nm in size) are taken up by the roots of the barley plants, and migrate to the plant leaves. Besides, NPs are phytotoxic for barley as they inhibit germination and pigment biosynthesis. This inhibition is probably due to the injury of the cell membranes in the roots. Therefore, the use of hematite NPs in agriculture and thereby their environmental diffusion must be addressed carefully.
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