Plants take up a wide range of trace metals/metalloids(hereinafter referred to as trace metals)from the soil,some of which are essential but become toxic at high concentrations(e.g.,Cu,Zn,Ni,Co),while others are non-e...Plants take up a wide range of trace metals/metalloids(hereinafter referred to as trace metals)from the soil,some of which are essential but become toxic at high concentrations(e.g.,Cu,Zn,Ni,Co),while others are non-essential and toxic even at relatively low concentrations(e.g.,As,Cd,Cr,Pb,and Hg).Soil contamination of trace metals is an increasing problem worldwide due to intensifying human activities.Trace metal contamination can cause toxicity and growth inhibition in plants,as well as accumulation in the edible parts to levels that threatens food safety and human health.Understanding the mechanisms of trace metal toxicity and how plants respond to trace metal stress is important for improving plant growth and food safety in contaminated soils.The accumulation of excess trace metals in plants can cause oxidative stress,genotoxicity,programmed cell death,and disturbance in multiple physiological processes.Plants have evolved various strategies to detoxify trace metals through cell-wall binding,complexation,vacuolar sequestration,efflux,and translocation.Multiple signal transduction pathways and regulatory responses are involved in plants challenged with trace metal stresses.In this review,we discuss the recent progress in understanding the molecular mechanisms involved in trace metal toxicity,detoxification,and regulation,as well as strategies to enhance plant resistance to trace metal stresses and reduce toxic metal accumulation in food crops.展开更多
Carbon-based nanomaterials have important research significance in various disciplines,such as composite materials,nanoelectronic devices,biosensors,biological imaging,and drug delivery.Recently,the human and ecologic...Carbon-based nanomaterials have important research significance in various disciplines,such as composite materials,nanoelectronic devices,biosensors,biological imaging,and drug delivery.Recently,the human and ecological risks associated with carbon-based nanomaterials have received increasing attention.However,the biological safety of carbon based nanomaterials has not been systematically studied.In this study,we used different types of carbon materials,namely,graphene oxide(GO),single-walled carbon nanotubes(SWCNTs),and multiwalled carbon nanotubes(MWCNTs),as models to observe their distribution and oxidative damage in vivo.The results of Histopathological and ultrastructural examinations indicated that the liver and lungs were the main accumulation targets of these nanomaterials.SR-μ-XRF analysis revealed that SWCNTs and MWCNTs might be present in the brain.This shows that the three types of carbon-based nanomaterials could cross the gas-blood barrier and eventually reach the liver tissue.In addition,SWCNTs and MWCNTs could cross the blood-brain barrier and accumulate in the cerebral cortex.The increase in ROS and MDA levels and the decrease in GSH,SOD,and CAT levels indicated that the three types of nanomaterials might cause oxidative stress in the liver.This suggests that direct instillation of these carbon-based nanomaterials into rats could induce ROS generation.In addition,iron(Fe)contaminants in these nanomaterials were a definite source of free radicals.However,these nanomaterials did not cause obvious damage to the rat brain tissue.The deposition of selenoprotein in the rat brain was found to be related to oxidative stress and Fe deficiency.This information may support the development of secure and reasonable applications of the studied carbon-based nanomaterials.展开更多
[Objective] To detect the effects of exposure to lead and cadmium on the oxidative damage of livers in laying hens. [Methods] One hundred and twenty 40-week-old Hyline brown hens were randomly divided into four groups...[Objective] To detect the effects of exposure to lead and cadmium on the oxidative damage of livers in laying hens. [Methods] One hundred and twenty 40-week-old Hyline brown hens were randomly divided into four groups. 100 mg / L Pb and / or 50 mg / L Cd was added into the drinking water for eight weeks. [Results] Compared with control group,AST and ALT activities in Pb group enhanced; but there were no significant differences. AST and ALT activities in Cd group and( Pb + Cd) group significantly or extremely significantly increased( P 【 0. 05 or P 【 0. 01). SOD activity,GSH- Px activity and GSH content in( Pb + Cd) group,Cd group and Pb group were significantly or extremely significantly lower than those in control group( P 【0. 05 or P 【0. 01). Among them,( Pb + Cd) group showed the greatest reduction( P 【0. 01). MDA contents in the three groups were significantly higher than that of control group; and( Pb +Cd) group was significantly higher than Pb group and Cd group. Cu,Fe and Zn contents in three groups were higher than those in control group in different degrees( P 【0. 05 or P 【0. 01). Se contents in Cd group and( Pb + Cd) group were significantly lower than that in control group( P 【0. 01). Residue contents in livers in Pb group and Cd group were significantly greater than that in control group; while residue content in( Pb + Cd) group was significantly higher than those in Pb group and Cd group. Ultrastructure showed that there were symptoms of mitochondrial swelling and fractured cristae in liver cells of laying hens after the exposure to Cd and Pb. In( Pb + Cd) group,these symptoms were even greater. [Conclusion] Oxidative damage and disturbance of trace element metabolism were one of the mechanisms for hepatotocity in laying hens induced by Pb and Cd,and synergistic effect lied in the coadministration.展开更多
Background: Immune dysfunction and a higher risk of uterine infections are characteristics of the transition into lactation in dairy cows. The supply of complexed trace minerals, which are more bioavailable, could hel...Background: Immune dysfunction and a higher risk of uterine infections are characteristics of the transition into lactation in dairy cows. The supply of complexed trace minerals, which are more bioavailable, could help overcome the greater needs of these nutrients in tissues around parturition and early lactation.Results: Twenty Holstein cows received an oral bolus with a mix of inorganic trace minerals(INO) or complexed trace minerals(AAC) to achieve 75, 65, 11, and 1 ppm supplemental Zn, Mn, Cu, and Co, respectively, in the total diet dry matter from -30 d through +30 d relative to parturition. Blood for polymorphonuclear leukocyte(PMNL) isolation was collected at-30,-15, +10, and + 30 d relative to parturition, whereas endometrium biopsies were performed at +14 and +30 d. Feeding AAC led to greater PMNL expression of genes related with inflammation response(DDX58), oxidative stress response(MPO), eicosanoid metabolism(PLA2G4A and ALOX5AP), transcription regulation(PPARG), and cellular adhesion(TLN1). The upregulation by AAC in endometrium of genes related with inflammation response( TLR2, TLR4, NFKB1, TNF, IL6, IL1 B, IL10, IL8), prostaglandin synthesis(PTGS2, PTGES), and antioxidant responses(NFE2 L2, SOD1) indicated a faster remodeling of uterine tissue and potentially greater capacity to control a local bacterial invasion.Conclusions: Data indicate that trace mineral supplementation from amino acid complexes improves PMNL activity and allows the prompt recovery of uterine tissue during early lactation. As such, the benefits of complexed trace minerals extend beyond an improvement of liver function and productive performance.展开更多
基金supported by the National Natural Science Foundation of China(31972500 and 41930758)the Key Research&Development Program of Jiangsu Province(BE2021717)。
文摘Plants take up a wide range of trace metals/metalloids(hereinafter referred to as trace metals)from the soil,some of which are essential but become toxic at high concentrations(e.g.,Cu,Zn,Ni,Co),while others are non-essential and toxic even at relatively low concentrations(e.g.,As,Cd,Cr,Pb,and Hg).Soil contamination of trace metals is an increasing problem worldwide due to intensifying human activities.Trace metal contamination can cause toxicity and growth inhibition in plants,as well as accumulation in the edible parts to levels that threatens food safety and human health.Understanding the mechanisms of trace metal toxicity and how plants respond to trace metal stress is important for improving plant growth and food safety in contaminated soils.The accumulation of excess trace metals in plants can cause oxidative stress,genotoxicity,programmed cell death,and disturbance in multiple physiological processes.Plants have evolved various strategies to detoxify trace metals through cell-wall binding,complexation,vacuolar sequestration,efflux,and translocation.Multiple signal transduction pathways and regulatory responses are involved in plants challenged with trace metal stresses.In this review,we discuss the recent progress in understanding the molecular mechanisms involved in trace metal toxicity,detoxification,and regulation,as well as strategies to enhance plant resistance to trace metal stresses and reduce toxic metal accumulation in food crops.
基金the National Natural Science Foundation of the Henan University(21IRTSTHN011).
文摘Carbon-based nanomaterials have important research significance in various disciplines,such as composite materials,nanoelectronic devices,biosensors,biological imaging,and drug delivery.Recently,the human and ecological risks associated with carbon-based nanomaterials have received increasing attention.However,the biological safety of carbon based nanomaterials has not been systematically studied.In this study,we used different types of carbon materials,namely,graphene oxide(GO),single-walled carbon nanotubes(SWCNTs),and multiwalled carbon nanotubes(MWCNTs),as models to observe their distribution and oxidative damage in vivo.The results of Histopathological and ultrastructural examinations indicated that the liver and lungs were the main accumulation targets of these nanomaterials.SR-μ-XRF analysis revealed that SWCNTs and MWCNTs might be present in the brain.This shows that the three types of carbon-based nanomaterials could cross the gas-blood barrier and eventually reach the liver tissue.In addition,SWCNTs and MWCNTs could cross the blood-brain barrier and accumulate in the cerebral cortex.The increase in ROS and MDA levels and the decrease in GSH,SOD,and CAT levels indicated that the three types of nanomaterials might cause oxidative stress in the liver.This suggests that direct instillation of these carbon-based nanomaterials into rats could induce ROS generation.In addition,iron(Fe)contaminants in these nanomaterials were a definite source of free radicals.However,these nanomaterials did not cause obvious damage to the rat brain tissue.The deposition of selenoprotein in the rat brain was found to be related to oxidative stress and Fe deficiency.This information may support the development of secure and reasonable applications of the studied carbon-based nanomaterials.
基金Supported by the Doctoral Fund Project of Jiangsu Institute of Poultry Sciences(JQ201201)Yangzhou Key Project of Agricultural Science and Technology(2012079)2014 Quality and Safety Risk Assessment Project of National Poultry Products(GJFP2014007)
文摘[Objective] To detect the effects of exposure to lead and cadmium on the oxidative damage of livers in laying hens. [Methods] One hundred and twenty 40-week-old Hyline brown hens were randomly divided into four groups. 100 mg / L Pb and / or 50 mg / L Cd was added into the drinking water for eight weeks. [Results] Compared with control group,AST and ALT activities in Pb group enhanced; but there were no significant differences. AST and ALT activities in Cd group and( Pb + Cd) group significantly or extremely significantly increased( P 【 0. 05 or P 【 0. 01). SOD activity,GSH- Px activity and GSH content in( Pb + Cd) group,Cd group and Pb group were significantly or extremely significantly lower than those in control group( P 【0. 05 or P 【0. 01). Among them,( Pb + Cd) group showed the greatest reduction( P 【0. 01). MDA contents in the three groups were significantly higher than that of control group; and( Pb +Cd) group was significantly higher than Pb group and Cd group. Cu,Fe and Zn contents in three groups were higher than those in control group in different degrees( P 【0. 05 or P 【0. 01). Se contents in Cd group and( Pb + Cd) group were significantly lower than that in control group( P 【0. 01). Residue contents in livers in Pb group and Cd group were significantly greater than that in control group; while residue content in( Pb + Cd) group was significantly higher than those in Pb group and Cd group. Ultrastructure showed that there were symptoms of mitochondrial swelling and fractured cristae in liver cells of laying hens after the exposure to Cd and Pb. In( Pb + Cd) group,these symptoms were even greater. [Conclusion] Oxidative damage and disturbance of trace element metabolism were one of the mechanisms for hepatotocity in laying hens induced by Pb and Cd,and synergistic effect lied in the coadministration.
基金Fernanda Batistel(FB)was supported by Coordenacao de Aperfeicoamento de Pessoal de Nível Superior(CAPES)Juan Loor(JL)was supported by National Institute of Food and Agriculture(Grant:ILLU-538-914)Zinpro Corporation provided support to Juan J.Loor and Michael T.Socha
文摘Background: Immune dysfunction and a higher risk of uterine infections are characteristics of the transition into lactation in dairy cows. The supply of complexed trace minerals, which are more bioavailable, could help overcome the greater needs of these nutrients in tissues around parturition and early lactation.Results: Twenty Holstein cows received an oral bolus with a mix of inorganic trace minerals(INO) or complexed trace minerals(AAC) to achieve 75, 65, 11, and 1 ppm supplemental Zn, Mn, Cu, and Co, respectively, in the total diet dry matter from -30 d through +30 d relative to parturition. Blood for polymorphonuclear leukocyte(PMNL) isolation was collected at-30,-15, +10, and + 30 d relative to parturition, whereas endometrium biopsies were performed at +14 and +30 d. Feeding AAC led to greater PMNL expression of genes related with inflammation response(DDX58), oxidative stress response(MPO), eicosanoid metabolism(PLA2G4A and ALOX5AP), transcription regulation(PPARG), and cellular adhesion(TLN1). The upregulation by AAC in endometrium of genes related with inflammation response( TLR2, TLR4, NFKB1, TNF, IL6, IL1 B, IL10, IL8), prostaglandin synthesis(PTGS2, PTGES), and antioxidant responses(NFE2 L2, SOD1) indicated a faster remodeling of uterine tissue and potentially greater capacity to control a local bacterial invasion.Conclusions: Data indicate that trace mineral supplementation from amino acid complexes improves PMNL activity and allows the prompt recovery of uterine tissue during early lactation. As such, the benefits of complexed trace minerals extend beyond an improvement of liver function and productive performance.
