Toxic Effects Of Cu Research Articles

Effect of soil P addition on growth, nutritional status and photosynthesis of potted grapevine plants grown under soil copper excess

The continuous use of copper (Cu)-based fungicides in viticulture to counteract fungal diseases has resulted in an accumulation of Cu in the topsoil, sometimes reaching toxic levels that can cause plant stress and reduce soil fertility. A possible strategy to mitigate the negative effects of Cu could include its incorporation into chemical compounds with phosphorous (P). The aim of this study was to evaluate the effectiveness of soil P addition on alleviating the toxic effect of Cu when applied in excess to potted grapevines plants. Micro-propagated plants of 1103 Paulsen rootstock were grown according to a factorial experimental design with two factors: Cu (4 levels: 0, 100, 200 and 300 mg kg-1 dw) and P (2 levels: 0 and 100 mg kg-1 dw) and three replicates. Sixty days after transplant, P was not effective in preventing the accumulation of Cu in vines. The total plant biomass was not influenced by soil Cu addition, while P increased plant growth by enhancing plant nutritional status. In addition, Cu reduced nutrient (P, K and Zn) content in plants. Net photosynthesis and efficiency of photosystem II decreased as a consequence of the increase of Cu concentration in soil. The effect of P in mitigating Cu toxicity was mainly related to the ability of plants to restore nutrient uptake.

Synergism and antagonisms between nutrients induced by copper toxicity in grapevine rootstocks: Monocropping vs. intercropping

The long-term use of Cu-containing fungicides contaminates vineyards soils, which can induce Cu toxicity and nutrient imbalances in several plant species. The aim of this work was to evaluate the effect of Cu toxicity on two grapevine rootstocks, Fercal and 196.17, and to elucidate if intercropping with oat can alleviate grapevine Cu toxicity. Plants were hydroponically-cultivated and treated with different Cu concentrations. At harvest the biomass accumulation, the SPAD index and the symplastic and apoplastic root and leaves ionome were measured to evaluate possible synergistic and/or antagonistic effects on other micro- and macronutrients. The root exudation analysis was correlated with genes expression (VvPEZ-like), whereas PCA analysis performed on the grapevine and oat ionome revealed that both mono- and intercropped 196.17 rootstock display a positive effect on Zn and Mn in the root tissues at high Cu concentrations. An increase of Zn and Mn in roots was also reported for the intercropped Fercal rootstock at high Cu concentrations while an antagonistic relation was reported for root Zn concentration in the monocropped Fercal rootstock. Our results showed that grapevine and oat compete for nutrient uptake and that this phenomenon can possibly alleviate grapevine Cu toxicity. However, Fercal rootstock is able to take advantage from oat, while 196.17 is disadvantaged by the intercropping system. Even though intercropping system seems to be a valuable tool to counteract grapevine Cu toxicity, the application of this agricultural practice has shown to be species dependent and should be evaluated for each rootstock.

Biochemical responses of the Protaetia brevitarsis Lewis larvae to subchronic copper exposure.

Copper (Cu) is one of the most commonly detected heavy metals in livestock manure pollution. Protaetia brevitarsis Lewis larvae are widely used in the decomposition of livestock manure. During decomposition, heavy metals in livestock manure can accumulate in P. brevitarsis larvae and affect normal growth and reproduction. Therefore, this research focused on characterizing the toxic effects of Cu to P. brevitarsis Lewis larvae. Larvae were exposed to Cu concentrations of 0, 100, 200, 400, and 800mgkg-1 in edible fungi residue for 7, 14, 21, and 28days. Results showed that the soluble protein content was markedly increased in 200 and 400mgkg-1 treatment groups on day 28. Compared to the control group, superoxide dismutase (SOD) and glutathione S-transferase (GST) activities were significantly stimulated on day 7 and then decreased as exposure length was increased (e.g., after 14, 21, and 28days). Catalase (CAT) activity was also significantly increased after 7days of exposure. Malondialdehyde (MDA) levels were markedly increased in the 100, 200, and 400mgkg-1 treatment groups on day 7. However, as time and Cu concentration were increased, MDA levels gradually decreased. These results indicate that Cu has biochemical effects on P. brevitarsis Lewis larvae, and both time and dose affect this biochemical response.

Effects of waterborne copper on toxicity stress and apoptosis responses in red seabream, Pagrus major

There has been an increasing trend of copper (Cu)-based aquaculture industry in the world, and it is necessary to evaluate the effect of copper ion exposure on water pollution. This study was aim to determine the critical concentration of toxic copper in adult red sea bream. Therefore, we investigated the effects of Cu toxicity on physiological stress and apoptosis exposed to various concentrations (10, 20, 30, and 40 μg/L). We measured physiological stress-related (corticotrophin- releasing hormone, adrenocorticotropic hormone, cortisol, and glucose), other toxic stress-related (metallothionein and Na+/K+-ATPase), and apoptosis-related (caspase-3 and hydrogen peroxide) parameters. In addition, we confirmed apoptosis. Physiological parameters were significantly increased from Cu concentration of 30 μg/L or more. However, no significant differences were observed after exposures at 10 and 20 μg/L. In addition, apoptotic cells were detected after exposure to 30 μg/L. The results of this study indicate that high concentrations induce stress and apoptosis compared to normal conditions.

Physiological responses of Porphyra haitanensis (Rhodophyta) to copper and cadmium exposure

Abstract The aim of the present work was to evaluate the effects of copper (Cu) and cadmium (Cd) on the physiology of the red macroalga Porphyra haitanensis Chang and Zheng. The alga was cultured in media with different Cu or Cd concentrations for 7 days. The relative growth rate was significantly reduced at Cu concentrations of 0.10 mg l−1 and above or at Cd concentrations of 4 mg l−1 and above. Chlorophyll a (Chl a), carotenoids (Car), phycoerythrin (PE) and phycocyanin (PC) contents decreased at high Cu or Cd concentrations, and PE content increased at 0.10 mg l−1 Cu or 4–8 mg l−1 Cd. Moreover, the optimal quantum yield, maximum net photosynthetic rate (Pm) and apparent photosynthetic efficiency (α) were significantly reduced at high Cu or Cd concentrations. In contrast, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity increased in response to Cu or Cd treatment. Catalase activity increased at 2–8 mg l−1 Cd and significantly declined at 0.50 mg l−1 Cu or 10 mg l−1 Cd. Nitrate reductase (NR) activity declined at high Cu or Cd concentrations. Consequently, both Cu and Cd were physiological stressors for P. haitanensis, with Cu being more toxic than Cd. This work has generated valuable knowledge about the toxic effects of Cu and Cd on macroalgae.

TOXIC EFFECTS OF CU(SO4) ON GILL AND LIVER TISSUES OF FRESH WATER CATFISH CLARIAS BATRACHUS (LINN.).

20Jan 2017 TOXIC EFFECTS OF CU(SO4) ON GILL AND LIVER TISSUES OF FRESH WATER CATFISH CLARIAS BATRACHUS (LINN.). Muneesh kumar , Anchal Raj and Rajesh Kumar. Department of Zoology Govt. Degree College Doda, University of Jammu, J&K, India. Department of Zoology G. G. M. Science College, Jammu, University of Jammu, J&K, India. Department of Zoology Govt. Banazir Science and Commerce College, Barkatullah University, (M.P.), India

BIO-CHEMICAL BIOMARKERS IN ALGAE SCENEDESMUS OBLIQUUS EXPOSED TO HEAVY METALS CD, CU AND ZN

Laboratory studies were conducted to determine the effects of different concentrations of Cu, Cd, Zn and mixture (equal concentrations from the three heavy metals) on growth and some oxidative stress (catalase and glutathione resuctase) on Scenedesmus obliquus (microalgae) after exposure to 24, 48, and 96 h. In addition, the uptake of Cu, Cd and Zn were determined in the culture medium after 24, 48 and 96h of exposure. The catalase and glutasthion resuctase enzyme activities were used as biomarkers to evaluate the toxic effects of Cu, Cd, Zn and mixture (equal concentrations from the three heavy metals) on the microalgae. Enzymatic activities were measured in the presence of each compound alone after 24, 48 and 96 h and also inmixture after the same time of exposure. The results showed that Cu, Cd, Zn and mixture induced antioxidative enzyme activities (CAT and GR) at different concentrations. Catalase activities (CAT) in both heavy metals treatedalgae were significantly increased. Additionally, a decrease in Chl.a, Chl.b and caritenoids was observed in algae after 24, 48 and 96 h of exposure to both Cu, Cd, Zn and mixture (equal concentrations from the three heavy metals).

Liming as an ameliorator of copper toxicity in black oat (Avena strigosa Schreb.)

ABSTRACTThis study aimed to assess the effect of liming as an ameliorator of copper (Cu) toxicity in black oats (Avena strigosa Schreb.) grown in soil with a sandy texture. The treatments were soil supplementation with increasing doses of lime (0.0, 0.5 and 1.0 g kg−1) and two of Cu (0 and 50 mg kg−1). Pre-germinated black oat seeds were sown for 30 days in the soil, subsequently, the plant height, root and shoot dry mass and concentration of total chlorophyll, chlorophylls a and b, carotenoids and total soluble carbohydrates and starch were analyzed. The dose of 50 mg kg−1 soil Cu caused a toxic effect on black oat plant growth and development, affected the internal distribution of nutrients, decreased the leaf chlorophyll concentration and increased the leaf concentration of total soluble carbohydrates and starch. Increasing lime doses ameliorated the toxic effects of Cu.

Physiological and biochemical mechanisms of silicon-induced copper stress tolerance in cotton (Gossypium hirsutum L.)

Accumulation of excess copper (Cu) in agricultural soils can decrease growth and quality of crops grown on these soils and a little information is available on the role of silicon (Si) in reducing Cu toxicity in plants. A hydroponic study was conducted to investigate the effects of Si (1.0 mM) on growth and physiology of cotton seedlings grown on different Cu (0, 25, and 50 µM) concentrations. Elevated levels of Cu decreased growth, biomass, photosynthetic pigments, and gas exchange characteristics, and increased the electrolyte leakage (EL), hydrogen peroxide (H2O2), and thiobarbituric acid reactive substances (TBARS) contents in leaf, stem, and roots of cotton seedlings. Cu stress alone decreased the activities of key antioxidant enzymes in cotton seedlings. Exogenous application of Si alleviated the toxic effects of Cu on cotton seedlings by improving growth, photosynthetic pigments, and gas exchange characteristics under Cu stress. The Si application decreased Cu concentrations in leaves, stem, and roots as compared with the control plants. Furthermore, Si decreased oxidative stress as evidenced by decreased EL, H2O2, and TBARS contents, and increased the antioxidant enzyme activities in cotton seedlings. This study provides evidences of Si-mediated reduction of Cu toxicity in cotton seedlings at physiological and biochemical levels.

Copper and zinc, but not other priority toxic metals, pose risks to native aquatic species in a large urban lake in Eastern China

Over the past 20 years, global production of copper (Cu) and zinc (Zn) rank in the top three compared to other metals such as Pb, Cd, Cr, Ni, As and Hg. However, due to the potential for exposure and toxicity to humans, more attention of environmental pollution was paid to other metals such as Cd and Hg. Aquatic organisms are sensitive to Cu and Zn. Even though internal concentrations of these required elements are homeostatically controlled, toxic effects can occur at the fish gill surface. In this work, concentrations in surface waters and toxic effects of Cu, Zn, Ni, Cr, Pb, Cd, As, Hg were determined and risk of various metals in Tai Lake, China were evaluated using both risk quotients and joint probability distributions. Two transition metals, Cu and Zn posed the greatest risks to aquatic organisms while measured concentrations of other metals were less than thresholds for adverse effects. Approximately 99.9% and 50.7% of the aquatic organisms were predicted to be affected by Cu and Zn in surface water of Tai Lake respectively. Our results highlight ecological risks of Cu and Zn in water of a typical, large, urban lake in Eastern China, which was ignored in the past.

Effect of Heavy Metals on Seed Germination of Trigonella foenum-graceum L

Effect of Heavy Metals on Seed Germination of Trigonella foenum-graceum L

Toxicity of Cu (II) to the green alga Chlorella vulgaris: a perspective of photosynthesis and oxidant stress.

The toxic effects of Cu (II) on the freshwater green algae Chlorella vulgaris and its chloroplast were investigated by detecting the responses of photosynthesis and oxidant stress. The results showed that Cu (II) arrested the growth of C. vulgaris and presented in a concentration- and time-dependent trend and the SRichards 2 model fitted the inhibition curve best. The chlorophyll fluorescence parameters, including qP, Y (II), ETR, F v /F m , and F v /F 0, were stimulated at low concentration of Cu (II) but declined at high concentration, indicating the photosystem II (PSII) of C. vulgaris was destroyed by Cu (II). The chloroplasts were extracted, and the Hill reaction activity (HRA) of chloroplast was significantly decreased with the increasing Cu (II) concentration under both illuminating and dark condition, and faster decline speed was observed under dark condition. Activities of superoxide dismutase (SOD) and catalase (CAT) and malondialdehyde (MDA) content were also significantly decreased at high concentration Cu (II), companied with a large number of reactive oxygen species (ROS) production. All these results indicated a severe oxidative stress on algal cells occurred as well as the effect on photosynthesis, thus inhibiting the growth of algae, which providing sights to evaluate the phytotoxicity of Cu (II).

Black Oat (Avena strigosa Schreb.) Growth and Root Anatomical Changes in Sandy Soil with Different Copper and Phosphorus Concentrations

Successive applications of copper-based (Cu) fungicides have increased Cu concentration in vineyard soils, inducing Cu toxicity in young vines and cover crops such as black oat, thus inhibiting growth and development. However, increasing soil phosphorus (P) content can reduce Cu toxicity symptoms. In this context, the aim of this study was to evaluate the effect of Cu toxicity and its alleviation by P fertilization in black oat cultivated in sandy soil. For the experiment, Typic Hapludalf soil samples were air-dried, prepared, and subjected to increasing doses of Cu (0, 30, and 60 mg kg−1) and P (0 and 100 mg kg−1). Subsequently, the soil was incubated and stored in pots, where black oat seedlings were grown for 30 days in a greenhouse. Plant roots subjected to Cu, especially with the highest Cu concentration and without P addition decreased the root cap size, showing early tissue differentiation and lateral root formation near the apical region. Decrease in dry matter (DM) production of roots (50 %) and shoots (67 %) was also observed in the highest Cu concentration. Plants without P addition, regardless of Cu concentration, also had lower root (33 %) and shoot (65 %) DM production. P addition in soil and its increased concentration reduced root anatomical changes and stimulated plant DM production. Therefore, we conclude that excessive Cu concentration alters black oat root anatomical structure, affecting plant growth, especially in sandy soils with low organic matter content. However, P supply can reduce root Cu toxicity symptoms, thus increasing plant dry matter production.

Glutamate ameliorates copper-induced oxidative injury by regulating antioxidant defences in fish intestine.

The objective of this study was to determine the protective effect of glutamate (Glu) in Cu-induced oxidative injury in fish intestine in vivo and enterocytes in vitro. The results indicated that exposure to 6 mg/l Cu for 72 h induced the production of reactive oxygen species, thereby increasing protein oxidation and lipid peroxidation in enterocytes of grass carp in vitro. Cells exposed to Cu alone resulted in a significant increase in lactate dehydrogenase release, which is accompanied by depletions of antioxidants, including total superoxide dismutase (T-SOD), glutathione S-transferase (GST), glutathione reductase (GR), anti-superoxide anion (ASA), anti-hydroxy radical (AHR) activities and GSH content. Pre-treatment with Glu remarkably prevented the toxic effects of Cu on the T-SOD, GST, GR, AHR, and ASA activities and GSH content in enterocytes. However, Cu induced an adaptive increase in the activities of catalase and glutathione peroxidase (GPx). Glu supplementation further increased GPx activity in enterocytes. Interestingly, the experiment in vivo showed that Glu pre-supplementation significantly elevated SOD, GPx, GST, GR, ASA and AHR activities, as well as GSH content. Further results showed that pre-treatment with Glu could alleviate Cu-induced oxidative injury by elevating antioxidant enzyme activities through regulating the expression of NF-E2-related nuclear factor 2 (Nrf2) mRNA. Together, these results indicated that Glu could attenuate Cu-induced cellular oxidative damage in fish intestine, likely mediated through Nrf2 signalling pathways regulating mRNA expressions of antioxidant enzyme genes and synthesis of GSH.

Dynamics of the diversity and structure of the overall and nitrifying microbial community in activated sludge along gradient copper exposures.

Diversity and composition of the microbial community, especially the nitrifiers, are essential to the treatment efficiency of wastewater in activated sludge systems. Heavy metals commonly present in the wastewater influent such as Cu can alter the community structure of nitrifiers and lower their activity. However, the dynamics of microbial community along a gradient of metal exposure have largely been unexplored, partially due to the limitations in traditional molecular methods. This study explored the dynamics regarding the diversity and community structures of overall and nitrifying microbial communities in activated sludge under intermittent Cu gradient loadings using Illumina sequencing. We created a new local nitrifying bacterial database for sequence BLAST searches. High Cu loadings (>10.9mg/L) impoverished microbial diversity and altered the microbial community. Overall, Proteobacteria was the predominant phylum in the activated sludge system, in which Zoogloea, Thauera, and Dechloromonas (genera within the Rhodocyclaceae family of the Beta-proteobacteria class) were the dominant genera in the presence of Cu. The abundance of unclassified bacteria at the phylum level increased substantially with increasing Cu loadings. Nitrosomonas and Nitrospira were the predominant nitrifiers. The nitrifying bacterial community changed through increasing abundance and shifting to Cu-tolerant species to reduce the toxic effects of Cu. Our local nitrifying bacterial database helped to improve the resolution of bacterial identification. Our results provide insights into the dynamics of microbial community in response to various metal concentrations in activated sludge systems and improve our understanding regarding the effect of metals on wastewater treatment efficiency.

Pre-soaking in indole-3-acetic acid or spermidine enhances copper tolerance in wheat seedlings

The effects of soaking wheat grains in 50μM indole-3-acetic acid (IAA) or in 1000μM spermidine (Spd) on seedling growth, drought tolerance, osmoprotectant molecule concentrations, anti-oxidant systems and stem anatomy when grown under 250 or 500μM copper stress were investigated. The plants exposed to Cu exhibited a substantial decline in growth, relative water content (RWC), soluble proteins and total soluble sugars, activities of superoxide dismutase (SOD), guaiacol peroxidase (GPOX) and ascorbate peroxidase (APOX) and stem tissues structure. IAA or Spd alleviated the adverse effects of Cu-stress to varying degrees. Despite the preference for Spd, soaking grains in either compound increased the seedling growth, the relative water content, osmoprotectant concentrations, the activity of the anti-oxidant system and improved stem tissues structure while it reduced electrolyte leakage compared to control grains soaked in distilled water. These findings are important as the potential of IAA or Spd to alleviate the harmful effects of Cu toxicity offers an opportunity to increase the resistance of wheat plants to growth under copper stress conditions. Furthermore, the protective action of Spd was more efficient than IAA.

Interaction between pH and Cu toxicity on fungal and bacterial performance in soil

pH is an important parameter affecting heavy metal toxicity in soil. Bacterial and fungal growth, and respiration, during 60 days were determined in response to Cu additions (up to 32 mmol Cu kg−1 soil) in four soils with pH varying between 4.5 and 7.8. We hypothesized that at higher pH the toxic effect of Cu would decrease. In soil with pH 7.8, no negative effects on microbial growth were found up to 32 mmol Cu kg−1 soil. In soils with pH 4.5, 5.5 and 6.9, increasing Cu initially resulted in decreasing bacterial growth and respiration, but with similar responses in all three soils. In these soils bacterial growth was the most sensitive microbial variable after 2 days, with 34–59% inhibition at 2 mmol Cu kg−1, and almost total inhibition at 16 mmol Cu kg−1 and above. Respiration was only inhibited to 32–67% at 16 mmol Cu kg−1. Bacterial growth recovered over time in soils with pH 4.5 and 5.5 and with 8 and 16 mmol Cu kg−1, resulting in no clear dose–response relationship. Soil respiration did not recover to levels in the unpolluted control. Fungal growth was not negatively affected by the Cu addition in short-term and even increased at high Cu levels. The Pollution Induced Community Tolerance (PICT) of the bacterial community to Cu increased with Cu level in soils with pH 4.5, 5.5 and 6.9, with effects already at 2–4 mmol Cu kg−1, while in the soil pH 7.8 only a small increase in PICT was found at 32 mmol Cu kg−1. PICT was closely correlated to the bacterial growth inhibition measured 2 days after Cu additions, suggesting that the PICT increase was mainly due to initial survival of tolerant bacteria. PICT was also closely correlated to water soluble Cu concentrations. High pH thus mitigated the toxic effect of Cu; this warrant pH to be included in decisions on limit values for Cu toxicity in soil.

Interactions and Toxicity of Cu-Zn mixtures to Hordeum vulgare in Different Soils Can Be Rationalized with Bioavailability-Based Prediction Models.

Soil contamination with copper (Cu) is often associated with zinc (Zn), and the biological response to such mixed contamination is complex. Here, we investigated Cu and Zn mixture toxicity to Hordeum vulgare in three different soils, the premise being that the observed interactions are mainly due to effects on bioavailability. The toxic effect of Cu and Zn mixtures on seedling root elongation was more than additive (i.e., synergism) in soils with high and medium cation-exchange capacity (CEC) but less than additive (antagonism) in a low-CEC soil. This was found when we expressed the dose as the conventional total soil concentration. In contrast, antagonism was found in all soils when we expressed the dose as free-ion activities in soil solution, indicating that there is metal-ion competition for binding to the plant roots. Neither a concentration addition nor an independent action model explained mixture effects, irrespective of the dose expressions. In contrast, a multimetal BLM model and a WHAM-Ftox model successfully explained the mixture effects across all soils and showed that bioavailability factors mainly explain the interactions in soils. The WHAM-Ftox model is a promising tool for the risk assessment of mixed-metal contamination in soils.

Synergistic effect of copper and low temperature over Listeria monocytogenes.

The capacity to grow at low temperatures has allowed Listeria monocytogenes to become one of the primary food pathogens to date, representing a major public health problem worldwide. Several works have described the homeostatic response of L. monocytogenes under different copper (Cu) treatments growing at mild temperature (30 °C). The aims of this report were to evaluate if changes in the external concentration of Cu affected viability and Cu homeostasis of L. monocytogenes growing at low temperature. Ours results showed that L. monocytogenes growing at 8 °C had a reduced viability relative to 30 °C when exposed to Cu treatments. This decrease was correlated with an increase in the internal concentration of Cu, probably linked to the transcriptional down-regulation of mechanisms involved in Cu homeostasis. This combined effect of Cu and low temperature showed a synergistic impact over the viability and homeostasis of L. monocytogenes, where low temperature exacerbated the toxic effect of Cu. These results can be useful in terms of the use of Cu as an antibacterial agent.

Reduction of copper phytotoxicity by liming: A study of the root anatomy of young vines (Vitis labrusca L.)

Frequent applications of copper (Cu)-based fungicides on vines causes the accumulation of this metal in vineyard soils, which can cause toxicity in young vines. However, liming may reduce these toxic effects. The present study aimed to evaluate the effects of Cu toxicity on the root anatomy of young vines and the alleviation of Cu toxicity by lime applications to contaminated sandy soil. The treatments consisted of the addition of lime (0.0, 1.5 and 3.0 Mg ha−1) and two Cu concentrations (0 and 50 mg kg−1) to Typic Hapludalf soil. Young vines ‘Niágara Branca’ (Vitis labrusca L.) were obtained by micropropagation and cultivated for 70 days. The young vines grown with Cu and without liming presented a disorganized root structure; reduced root cap size; increased diameter (47%), cortex area (128%), vascular cylinder area (93%), and number of cortical layers and cells containing phenolic compounds (132%); and reduced root (41%), stem (44%) and leaf dry mass (21%) and height increase (55%). Moreover, Cu exposure reduced Ca concentrations (13%) and increased Cu concentrations (371%) in the roots. Liming, primarily with the highest tested dose, increased the soil pH (from 4.4 to 5.4–6.1), decreased the Cu concentration in the soil (extracted by CaCl2), increased the calcium (Ca) and magnesium (Mg) uptake by plants, prevented root anatomical changes and benefited young vine growth in soil with higher Cu concentrations.