RESUMEN

Nanotechnologies can improve plant growth, protect it from pathogens, and enrich it with bioactive and mineral substances. In order to fill the lack of knowledge about the combined environmental effects of lighting and nanoparticles (NPs) on plants, this study is designed to investigate how different HPS and LED lighting combined with CuO and ZnO NPs influence the elemental composition of ice plants (Mesembryanthemum crystallinum L.). Plants were grown in hydroponic systems with LED and HPS lighting at 250 ± 5 µmol m-2 s-1 intensity, sprayed with aqueous suspensions of CuO (40 nm, 30 ppm) and ZnO (35-45 nm, 800 ppm) NPs; their elemental composition was measured using an ICP-OES spectrometer and hazard quotients were calculated. LED lighting combined with the application of ZnO NPs significantly affected Zn accumulation in plant leaves. Cu accumulation was higher when plants were treated with CuO NPs and HPS illumination combined. The calculated hazard quotients showed that the limits are not exceeded when applying our selected concentrations and growth conditions on ice plants. In conclusion, ice plants had a more significant positive effect on the accumulation of macro- and microelements under LED lighting than HPS. NPs had the strongest effect on the increase in their respective microelements.

RESUMEN

The ferric chelate reductase (FRO) family plays a vital role in metal ion homeostasis in a variety of locations in the plants. However, little is known about this family in peanut (Arachis hypogaea). This study aimed to identify FRO genes from the genomes of peanut and the two diploid progenitors (A. duranensis and A. ipaensis) and to analyze their gene/protein structures and evolution. In addition, transcriptional responses of AhFRO genes to Fe deficiency and/or Cu exposure were investigated in two peanut cultivars with different Fe deficiency tolerance (Silihong and Fenghua 1). A total of nine, four, and three FRO genes were identified in peanut, A. duranensis, and A. ipaensis, respectively, which were divided into three groups. Most AhFRO genes underwent WGD/segmental duplication, leading to the expansion of the AhFRO gene family. In general, clustered members share similar gene/protein structures. However, significant divergences occurred in AhFRO2 genes. Three out of five AhFRO2 genes were lowly expressed in all tissues under normal conditions, which may be beneficial for avoiding gene loss. Transcription analysis revealed that AhFRO2 and AhFRO7 genes might be involved in the reduction of Fe/Cu in plasma membranes and plastids, respectively. AhFRO8 genes appear to confer Fe reduction in the mitochondria. Moreover, Fe deficiency induced an increase of Cu accumulation in peanut plants in which AhFRO2.2/2.4/2.5 and FRO7.1/7.2 might be involved. Our findings provided new clues for further understanding the roles of AhFRO genes in the Fe/Cu interaction in peanut.

RESUMEN

This study aims to investigate the ability of an imidazolium biobased Zwitterionic Ionic Liquids (ZILs) in enhancing the phytoavailability of copper from garden (G) and vineyard (V) soils using the model plant ryegrass. Uncontaminated and artificially contaminated CuSO4 soils, unamended and ZIL-amended soil modalities were designed. The copper/ZIL molar ratio (1/4) introduced was rationally established based on molecular modeling and on the maximal copper concentration in artificially contaminated soil. Higher accumulation of copper in the shoots was detected for the uncontaminated and copper contaminated ZIL amended V soils (18.9 and 23.3 mg/kg, respectively) contrary to G soils together with a ZIL concentration of around 3% (W/W) detected by LC-MS analyses. These data evidenced a Cu-accumulation improvement of 38% and 66% compared to non-amended V soils (13.6 and 13.9 mg/kg respectively). ZIL would be mainly present under Cu(II)-ZIL4 complexes in the shoots. The impact on the chemical composition of shoot was also studied. The results show that depending on the soils modalitity, the presence of free copper and/or ZIL led to different chemical compositions in lignin and monomeric sugar contents. In the biorefinery context, performances of enzymatic hydrolysis of shoots were also related to the presence of both ZIL and copper under free or complex forms. Ecotoxicity assessment of the vineyard soil samples indicated that the quantity of copper and ZIL remaining in the soils had no significant toxicity. ZIL amendment in a copper-contaminated soil was demonstrated as being a promising way to promote the valorization of phytoremediation plants.

Asunto(s)

Líquidos Iónicos , Contaminantes del Suelo , Cobre/química , Líquidos Iónicos/toxicidad , Contaminantes del Suelo/análisis , Suelo/química , Biodegradación Ambiental , Plantas

RESUMEN

Excess copper (Cu) causes the toxic effects in plants and health hazards to humans. Therefore, in this study, the effect of sodium silicate (1 mM Si) and sodium nitroprusside (200 µM SNP as a releasing NO), was assessed on Cu tolerance in Salvia officinalis L. plants exposed to 400 µM CuSO4. Results revealed that the combined supplementation with Si and SNP rather than the single application of these chemicals lowered Cu concentrations and translocation factor and increased Mg, Zn, and Fe concentrations in roots and shoots. Furthermore, combined treatment more efficiently decreased electrolyte leakage enhanced the activities of POD and APX in the leaves and roots, and improved relative water content and the content of Chl. a and Chl. b in leaves and consequently further increased tolerance index. Silicon supply enhanced NO content and applying Si + SNP more than the treatment of Si alone increased Si concentrations in the roots and shoots under Cu stress. Therefore, the reciprocal interaction of Si and NO might enhance Cu tolerance in plants, and the combined application of Si and SNP might be a promising strategy to decrease heavy metal accumulation in medicinal plants grown in polluted lands.

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In most studies, co-precipitation of silicon and heavy metals in medium has been suggested as a reason for reducing heavy metal uptake in plants. In this study, the impact of Si on NO generation and the role of NO signaling in regulating Cu uptake and translocation and defensive responses were assessed to clarify another mechanism of Si in inducing Cu tolerance in sage. Furthermore, the combined application of Si and SNP has been indicated as an innovative strategy to enhance Cu tolerance and decrease heavy metal accumulation in medicinal plants grown in polluted lands.

Asunto(s)

Cobre , Salvia officinalis , Humanos , Cobre/toxicidad , Óxido Nítrico/farmacología , Silicio/farmacología , Biodegradación Ambiental , Antioxidantes/farmacología , Raíces de Plantas

RESUMEN

Copper ion (Cu2+) and copper oxide (CuO) nanoparticle (NP) ecotoxicity are of increasing concern as they are considered to be a potential risk to marine systems. This study represents the first attempt to evaluate CuO NP impacts on the seaweeds and Cu2+ on the chlorophyte Ulva rigida. Effects on oxidative stress, antioxidant defence markers, photosystem II function, thalli growth, and cell viability in U. rigida exposed for 4 up 72 h to1 and 5 mg L-1 Cu2+ and CuO NPs were examined. Hydrogen peroxide (H2O2) generation, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and growth inhibition seemed to be reliable and early warning markers of toxicity. The most important variables of the principal component analysis (PCA): H2O2 generation, antioxidant stress markers, and growth-based toxicity index, were higher at 1 mg L-1 CuO NPs compared to CuSO4 and at 5 mg L-1 CuSO4 compared to CuO NPs. Intracellular uptake kinetics fit well to the Michaelis-Menten equation. The higher toxicity at 5 mg L-1 CuSO4 compared to 1 mg L-1 was due to the higher Cu uptake with increasing concentration, suggesting and higher accumulation ability. On the contrary, 1 mg L-1 CuO NPs induced more strongly toxicity effects than 5 mg L-1. The relatively stronger effect of CuO NPs at 1 mg L-1 than the respective CuSO4 concentration could be attributed to the higher rate of initial uptake (Vc) and the mean rate of Cu uptake [Cmax/(2 × Km)] at CuO NP treatment. The intracellular seaweed experimental threshold of Cu, which coincided with the onset of oxidative stress, was within the Cu concentration range recorded in Mediterranean Ulva spp., indicating that it may pose a substantial risk to marine environments.

Asunto(s)

Nanopartículas del Metal , Nanopartículas , Algas Marinas , Ulva , Contaminantes Químicos del Agua , Antioxidantes , Cobre/análisis , Peróxido de Hidrógeno , Iones , Cinética , Nanopartículas del Metal/toxicidad , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad

RESUMEN

In recent years, pollution by heavy metals (HM) has become an increasingly serious problem in forest ecosystems, making their remediation a primary research focus in China. Poplars are ideal candidates for phytoremediation because of their great commercial value, ability to produce large biomass, and high capacity for HM uptake. The individual and combined effects of copper (Cu) and lead (Pb) on Populus yunnanensis growth and physiology were tested for both male and female potted plants in four treatment groups: control, Pb only (1,000 mg kg-1 PbAc dry soil), Cu only (400 mg kg-1 CuSO4·5H2O dry soil), and combined Pb and Cu. Each treatment group contained 25 male and 25 female individuals. The experimental duration was 3 months. Compared with the control plants, the Cu and Pb treatment groups experienced reduced leaf, stem, root, and total biomass for both sexes, but the impact on growth rate was more severe in females than in males. The cellular ultrastructure of leaves was extensively damaged in both male and female trees but was more severely damaged in females. Male trees demonstrated a stronger Cu absorption ability with a bioconcentration factor 2.30 times that of females. Significant changes in pigment content, membrane lipid peroxidation, and protein oxidation (carbonyl) also indicated that females were more sensitive than males to Cu- and Pb-induced stress. The higher Cu and Pb tolerance in males correlated with better H2O2 scavenging ability and proline accumulation. Nevertheless, the combined stress from both Cu and Pb yielded greater negative effect on the growth and physiology of P. yunnanensis for both sexes.

Asunto(s)

Cobre , Plomo , Metales Pesados , Populus , Contaminantes del Suelo , Biodegradación Ambiental , China , Cobre/toxicidad , Ecosistema , Humanos , Peróxido de Hidrógeno , Plomo/toxicidad , Populus/efectos de los fármacos , Populus/crecimiento & desarrollo , Suelo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad

RESUMEN

Environmental contaminants such as metal ions can have detrimental effects on aquatic organisms at the molecular, organismal and population levels. In the present work, we examined the interactive effect of Cu(II) and conspecific alarm substance on zebrafish behavioural responses utilizing the novel tank diving assay. To this end, 3 novel tank diving tests (on day 0, 3 and 10 of the experimental phase) were conducted on zebrafish in 4 experimental groups: (1) control: no Cu(II) and no alarm substance, (2) Cu(II) only: exposed to 0.78 µM Cu(II) (25 % of the 240 h LC50) in the home tank for 10 days, (3) alarm substance only: exposed to alarm substance for 6 min concomitant with behavioural testing, and (4) Cu(II) + alarm substance: exposed to 0.78 µM Cu(II) in the home tank for 10 days and treated with alarm substance for 6 min during the behavioural testing. Results showed robust habituation response of zebrafish. Exposure to Cu(II) did not affect the behavioural phenotypes of zebrafish in the novel tank diving test or habituation responses. Alarm substance treatment evoked strong anxiety-like behaviour. Finally, zebrafish in the Cu(II) + alarm substance group lost their sensitivity to alarm substance in repeated novel tank assays throughout the concomitant Cu(II) exposure; this observation is tentatively ascribed to Cu(II)-induced olfactory impairment.

Asunto(s)

Ansiedad/fisiopatología , Conducta Animal/efectos de los fármacos , Sulfato de Cobre/farmacología , Olfato/efectos de los fármacos , Animales , Conducta Animal/fisiología , Muerte , Buceo , Habituación Psicofisiológica/efectos de los fármacos , Habituación Psicofisiológica/fisiología , Locomoción/efectos de los fármacos , Trastornos del Olfato , Pez Cebra

RESUMEN

Copper is an essential element in many biological processes, but may exert toxic effects at levels surplus to metabolic requirements. Herein we assess the effect of copper on zebrafish behaviour using two assays, namely the novel tank diving test and a T-maze test with food reward. Novel tank diving tests were conducted on days 0, 4, and 10 of a 10 day Cu exposure (at concentrations of 0.77 µM (25% of the 240 h LC50) and 1.52 µM (50% of the 240 h LC50) to assess the alterations of behavioural responses in repeating novel tank diving assays and the effect of Cu on these patterns. Results demonstrate habituation to novelty, which is an indicator of spatial memory. Copper exposure had no effect on the latency of entry into the upper zones of the tank, nor on the total time spent therein, but did cause a greater number of freezing bouts in comparison to the control group. Additionally, Cu exposure had no effect on the habituation responses of zebrafish. Using the T-maze assay, we tested the effect of prior exposure to Cu for 10 days on subsequent behavioural trainings. The T-maze protocol was based on associative learning, where a visual stimulus (colour) was linked with a natural stimulus (food). Results of the control group showed that zebrafish are able to perform associative learning tasks. Moreover, Cu was found to negatively affect the associative learning capabilities. Specifically, while zebrafish in the control group achieved a significant number of correct choices (leading to food reward) throughout the T-maze training, such a trend was not observed for Cu exposed fish. Thus at the exposure concentrations and exposure times considered herein, Cu has no determinative impact on instinctual behavioural responses of zebrafish in repeated novel tank diving assays but does limit the associative learning capabilities.

Asunto(s)

Aprendizaje por Asociación/efectos de los fármacos , Conducta Animal/efectos de los fármacos , Cobre/toxicidad , Aprendizaje por Laberinto/efectos de los fármacos , Memoria Espacial/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Pez Cebra/fisiología , Animales , Carga Corporal (Radioterapia) , Cobre/metabolismo , Actividad Motora/efectos de los fármacos , Contaminantes Químicos del Agua/metabolismo , Pez Cebra/metabolismo

RESUMEN

Cu accumulation in the internodal cell of charophyte Nitellopsis obtusa or its compartments was investigated after 3-h-exposure to lethal effective concentrations (8-day LC50) of CuO nanoparticle (nCuO) suspension or CuSO4 solution, i.e. 100 mg/L nCuO or 3.18 mg Cu/L as CuSO4. In both cases, the major part of Cu accumulated in the cell walls. The presence of CuO NPs in the cell wall and within the cell was visualized by scanning electron microscope images as well as confirmed by energy dispersive X-ray spectrum data. Although a threefold higher intracellular concentration of Cu was found after treatment with nCuO suspension, 3.18 mg Cu/L as CuSO4 induced fast and substantial depolarization of cell membrane potential contrary to that of 100 mg/L nCuO. A delayed effect of nCuO on the survival of the cells was also observed. This suggests that internally accumulated Cu was far less active and further supports the hypothesis of delayed toxicity of internalized nCuO NPs to charophyte cells.

Asunto(s)

Carofíceas/metabolismo , Cobre/metabolismo , Nanopartículas del Metal/toxicidad , Compartimento Celular , Carofíceas/efectos de los fármacos , Cobre/toxicidad , Suspensiones

RESUMEN

Toxic effects of copper (Cu) were analyzed in young plants of Inga subnuda subs. luschnathiana, a species that is highly tolerant to flooding and found in Brazil in wetlands contaminated with Cu. Plants were cultivated in fully nutritive solution, containing different concentrations of Cu (from 0.08 µmol to 0.47 mmol L(-1)). Symptoms of Cu toxicity were observed in both leaves and roots of plants cultivated from 0.16 mmol Cu L(-1). In the leaves, Cu clearly induced alterations in the thickness of the epidermis, mesophyll, palisade parenchyma, and intercellular space of the lacunose parenchyma. Also, this metal induced disorganization in thylakoid membranes, internal and external membrane rupture in chloroplasts, mitochondrial alterations, and electrodense material deposition in vacuoles of the parenchyma and cell walls. The starch grains disappeared; however, an increase of plastoglobule numbers was observed according to Cu toxicity. In the roots, destruction of the epidermis, reduction of the intercellular space, and modifications in the format of initial cells of the external cortex were evident. Cell walls and endoderm had been broken, invaginations of tonoplast and vacuole retractions were found, and, again, electrodense material was observed in these sites. Mineral nutrient analysis revealed higher Cu accumulation in the roots and greater macro- and micronutrients accumulation into shoots. Thus, root morphological and ultrastructural changes induced differential nutrients uptake and their translocations from root toward shoots, and this was related to membrane and endoderm ruptures caused by Cu toxicity.

Asunto(s)

Cobre/toxicidad , Fabaceae/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Brasil , Oxalato de Calcio/metabolismo , Pared Celular/metabolismo , Pared Celular/ultraestructura , Cobre/análisis , Fabaceae/metabolismo , Fabaceae/ultraestructura , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Hojas de la Planta/ultraestructura , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , Raíces de Plantas/ultraestructura , Tilacoides/metabolismo , Contaminantes Químicos del Agua/análisis , Humedales

RESUMEN

Copper (Cu) is an important environmental pollutant that exerts harmful effects on all living organisms when in excess. In an effort to remove this toxin in situ, a bacterial Cu-binding protein gene CusF was engineered to target CusF for secretion to the cell wall and vacuoles and for accumulation in the cytoplasm. Analysis of transgenic Arabidopsis plants showed that CusF was functionally active and that plants expressing cell wall- (CusFcw transgenic lines) or vacuole-targeted CusF (CusFvac transgenic lines) were more resistant to Cu excess than untransformed plants and plants with cytoplasmic CusF (CusFcyto transgenic lines). Under short-term (48 h) exposure to Cu excess, CusFcw transgenic lines showed up to 2-fold increased Cu accumulation in roots compared with the untransformed plants; however, CusFcyto lines and the wild-type plants had similar Cu concentrations in both roots and shoots. Under long-term (40 d) exposure to Cu excess, all transgenic lines accumulated more Cu (up to 3-fold) in roots than the untransformed plants, whereas only CusFcyto lines showed a marked increase (∼3-fold of the wild-type plants) of Cu accumulation in shoots. In addition, expression of CusF in the cytosol dramatically enhanced Cu transport from roots to shoots when compared with plants with secretory pathway-targeted CusF. Our results demonstrate the feasibility of Cu tolerance and accumulation by engineering Cu-binding proteins targetable to subcellular compartments and provide new insights into the multifaceted mechanisms of Cu partitioning between roots and shoots.

Asunto(s)

Arabidopsis/metabolismo , Proteínas de Transporte de Catión/metabolismo , Cobre/metabolismo , Proteínas de Escherichia coli/metabolismo , Regulación de la Expresión Génica de las Plantas , Arabidopsis/citología , Arabidopsis/genética , Biodegradación Ambiental , Transporte Biológico , Proteínas de Transporte de Catión/genética , Pared Celular/metabolismo , Proteínas Transportadoras de Cobre , Citosol/metabolismo , Proteínas de Escherichia coli/genética , Expresión Génica , Genes Reporteros , Fenotipo , Raíces de Plantas/citología , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Brotes de la Planta/citología , Brotes de la Planta/genética , Brotes de la Planta/metabolismo , Plantas Modificadas Genéticamente , Proteínas Recombinantes de Fusión , Plantones/citología , Plantones/genética , Plantones/metabolismo , Vacuolas/metabolismo