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1.
The effect of Al and Cd on the growth, photosynthesis, and accumulation of Al, Cd and plant nutrients in two soybean genotypes were determined using hydroponic culture. There were six treatments: pH 6.5; pH 4.0; pH 6.5 1.0 μmol/L Cd; pH 4.0 1.0 μmol/L Cd; pH 4.0 150 μmol/L Al; pH 4.0 1.0 μmol/L Cd 150 μmol/L Al. The low pH (4.0) and Al treatments caused marked reduction in root length, shoot height, dry weight, chlorophyll content (SPAD value) and photosynthetic rate. Al-sensitive cv. Zhechun 2 accumulated comparatively more Al and Cd in plants than Al-tolerant cv. Liao 1. Compared with pH 6.5, pH 4.0 resulted in significant increase in Cd and Al concentration in plants. Combined application of Cd and Al enhanced their accu-mulation in roots, but caused a reduction in shoots. The concentrations of all 10 nutrients (P, K, Ca, Mg, Fe, Mn, Cu, Zn and B), except Mo were also increased when plants were exposed to pH lower than pH 6.5. Al addition caused a reduction in the con-centration of most nutrients in plant roots and shoots; but K, Mn and Zn in roots were increased. Treatments with Cd alone or together with Al reduced the concentrations of all the plant nutrients in plants. Al-sensitive genotype Zhechun 2 has lower nutrient concentration than Al-tolerant genotype Liao 1. The current findings imply that Al and Cd are synergistic in their effect on plant growth, physiological traits and nutrient uptake.  相似文献   

2.
Interaction of salinity （NaCI） and cadmium （Cd） on growth, mineral nutrients, Na and Cd accumulation in four barley genotypes differing in salt tolerance was studied in a hydroponic experiment. Cd, NaCI and their combined stresses reduced Ca and Mg concentrations in roots and shoots, K concentration in shoots, increased K and Cu concentrations in roots relative to control, but had non-significant effect on micronutrients Cu, Fe and Mn concentrations in shoot. The three stresses reduced accumulation of most tested nutrients in both roots and shoots, except NaCI and NaCl＋Cd stresses for root K and shoot Cu accumulation in salt tolerant genotypes. The salt tolerant genotypes did not have higher nutrient concentration and accumulation than the sensitive ones when exposed to Cd and NaCI stresses. In conclusion, the affecting mechanism of Cd stress on nutrients was to some extent different from salinity stress, and the NaCl＋Cd stress was not equal to additional Cd and NaCI stresses, probably due to the different valence and competitive site of Na^＋ and Cd^2＋. NaCI addition in the Cd-containing medium caused remarkable reductions in both Cd concentration and accumulation, with the extent of reduction being also dependent on genotypes. The salt-tolerant genotypes had lower Na concentration than sensitive ones.  相似文献   

3.
Sedum alfredii Hance has been identified as zinc (Zn) and cadmium (Cd) co-hyperaccumulator. In this paper the relationships of Zn or Cd hyperaccumulation to the generation and the role of H2O2 in Sedum alfredii H. were examined, The results show that Zn and Cd contents in the shoots of Sedum alfredii H. treated with 1000 μmol/L Zn2 and/or 200 μmol/L Cd2 increased linearly within 15 d. Contents of total S, glutathione (GSH) and H2O2 in shoots also increased within 15 d, and then decreased. Total S and GSH contents in shoots were higher under Cd2 treatment than under Zn2 treatment. However, reverse trends of H2O2 content in shoots were obtained, in which much higher H2O2 content was observed in Zn2 -treated shoots than in Cd2 -treated shoots. Similarly, the microscopic imaging of H2O2 accumulation in leaves using H2O2 probe technique showed that much higher H2O2 accumulation was observed in the Zn2 -treated leaf than in the Cd2 -treated one. These results suggest that there are different responses in the generation of H2O2 upon exposure to Zn2 and Cd2 for the hyperaccumulator Sedum alfredii H. And this is the first report that the generation of H2O2 may play an important role in Zn hyperaccumulation in the leaves. Oar results also imply that GSH may play an important role in the detoxification of dissociated Zn/Cd and the generation of H2O2.  相似文献   

4.
The elucidation of a natural strategy for metal hyperaccumulation enables the rational design of technologies for the clean-up of metal-contaminated soils.Organic acid has been suggested to be involved in toxic metallic element tolerance,translocation,and accumulation in plants.The impact of exogenous organic acids on cadmium(Cd) uptake and translocation in the zinc(Zn)/Cd co-hyperaccumulator Sedum alfredii was investigated in the present study.By the addition of organic acids,short-term(2 h) root uptake of 109 Cd increased significantly,and higher 109 Cd contents in roots and shoots were noted 24 h after uptake,when compared to controls.About 85% of the 109 Cd taken up was distributed to the shoots in plants with citric acid(CA) treatments,as compared with 75% within controls.No such effect was observed for tartaric acid(TA).Reduced growth under Cd stress was significantly alleviated by low CA.Long-term application of the two organic acids both resulted in elevated Cd in plants,but the effects varied with exposure time and levels.The results imply that CA may be involved in the processes of Cd uptake,translocation and tolerance in S.alfredii,whereas the impact of TA is mainly on the root uptake of Cd.  相似文献   

5.
The effects of salinity(50 mmol/L NaCl) and Cd(1 μmol/L CdCl2) as sole and combined on growth and photosyn-thetic parameters were studied using two soybean genotypes,Huachun 18 and NGB.The concentrations of Cd2 ,Zn2 ,Ca2 ,Mg2 ,K and Na were also determined in seeds and pods.Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate(Pn) in the treatments of salinity stress alone and combined stress(NaCl Cd),showing that it is relatively sensitive to salinity.The decrease in Pn caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency(the ratio of variable fluorescence to maximal fluorescence,Fv/Fm),whereas the decease in NGB was mainly related to reduced stomatal conductance(Gs).The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone.Greater change in the pod concentrations of Zn2 ,Ca2 ,Mg2 ,K and Na was detected under salt stress for Huachun 18 than for NGB.The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes.  相似文献   

6.
Copper accumulation and intracellular distribution in Elsholtzia splendens, a native Chinese Cu-tolerant and accumulating plant species, was investigated by transmission electron microscope (TEM) and gradient centrifugation techniques.Copper concentrations in roots, stems and leaves of E. splendens increased with increasing Cu levels in solution. After exposure to 500 μmol/L Cu for 8 d, about 1000 mg/kg Cu were accumulated in the stem and 250 mg/kg Cu in the leaf of E. splendens. At 50μmol/L Cu, no significant toxicity was observed in the chloroplast and mitochondrion within its leaf cells, but separation appeared at the cytoplasm and the cell wall within the root cells. At ＞250 μmol/L Cu, both root and leaf organelles in E. splendens were damaged heavily by excessive Cu in vivo. Copper subcellular localization in the plant leaf after 8 days' exposure to 500 μmol/L Cu using gradient centrifugation techniques was found to be decreased in the order: chloroplast＞cell wall＞soluble fraction＞other organelles. The plant root cell wall was found to be the site of highest Cu localization. Increase of Cu exposure time from 8 d to 16d, increased slightly Cu concentration in cell wall fraction in roots and leaves, while that in the chloroplast fraction decreased in leaves of the plants grown in both 0.25 μmol/L and 500 μmol/L Cu. TEM confirmed that much more Cu localized in cell walls of E. splendens roots and leaves, but also more Cu localized in E. splendens' chloroplast when the plant is exposed to Cu levels＞250μmol/L, as compared to those in the plant grown in 0.25 μmol/L Cu. Copper treatment at levels＞250 μmol/L caused pronounced damage in the leaf chloroplast and root organelles. Copper localization in cell walls and chloroplasts could mainly account for the high detoxification of Cu in E. splendens.  相似文献   

7.
Objective: To construct a PC12 cell strain with neuronal differentiation, and observe the apoptosis and pro-liferation activity effects induced these cells by Amyloid beta-Protein (Aβ-43). Methods: 1) PC12 cells in logarithmicgrowth phase were subcultured for 24 h. After the culture fluid was changed, the cells were treated with Rat-β-NGF andcultured for 9 days. 2) Neuronal differentiation of PC12 cells in logarithmic growth phase were divided into four groups:control group (0), experimental group (1), experimental group (2) and experimental group (3). The concentrations of Aβ inthe four groups were 0 μmol/L, 1.25 μ mol/L, 2.5 μ mol/L and 5 μmol/L, respectively. The cells were harvested at 24, 48 and72 h later and stained with AnnexinV-FITC/PI after centrifugation and washing. Then flow cytometry was conducted toexamine the apoptosis percentage. 3) NGF-induced PC12 cells were selected and Aβ with different concentrations wasadded. The final concentrations of Aβ were 0 μmol/L, 1.25 μmol/L, 2.5 μmol/L and 5 μ mol/L, respectively. After the cellswere incubated in an atmosphere of 5% CO2 at 37 ℃ in an incubator for 72 h, the OD values were examined. Results: 1)Neuronal differentiated PC 12 cell lines were successfully established. 2) Flow cytometric examination indicated that Aβ(1.25, 2.5, and 5.0 μmol/L) could effectively induce apoptosis of neuronal-differented cells at the 24 h, 48 h and 72 h timepoints. 3) Aβ (0-5.00 μ mol/L) had no obvious effect on proliferation or restraining of the neuronal differentiation of thePC 12 cells after a 72 h interacting process. Conclusion: This investigation revealed successful neuronal differentiation of thePC12 cell strain. The induction of apoptosis of the neurocytes by various concentrations of Aβ was observed and the in-fluence of Aβ on induced proliferation of PC 12 cells by Rat-β-NGF was revealed. This study -05 provide basis for futureresearch on the molecular cure of AD and interdiction of AD evolution.  相似文献   

8.
The effects of salinity （50 mmol/L NaCI） and Cd （1 μmol/L CdCl2） as sole and combined on growth and photosynthetic parameters were studied using two soybean genotypes, Huachun 18 and NGB. The concentrations of Cd^2＋, Zn^2＋, Ca^2＋, Mg^2＋, K^＋ and Na^＋were also determined in seeds and pods. Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate （P,） in the treatments of salinity stress alone and combined stress （NaCl＋Cd）, showing that it is relatively sensitive to salinity. The decrease in P, caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency （the ratio of variable fluorescence to maximal fluorescence, Fv/Fm）, whereas the decease in NGB was mainly related to reduced stomatal conductance （Gs）, The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone. Greater change in the pod concentrations of Zn^2＋, Ca^2＋, Mg^2＋, K^＋ and Na^＋was detected under salt stress for Huachun 18 than for NGB. The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes.  相似文献   

9.
Effect of cadmium on growth and photosynthesis of tomato seedlings   总被引：9，自引：0，他引：9  
A hydroponic experiment carried out to study the effect of five Cd levels on growth and photosynthesis of two tomato cultivars showed that the addition of 0.1 μmol/L Cd induced a slight increase in plant height of Hezuo 903 and the SPAD (the Soil-Plant Analyses Development) value of the 2 cultivars. However, at higher Cd levels, i.e., 1 and 10 μmol/L, root length and volume, plant height, and SPAD value were all significantly reduced. On an average of the 2 cultivars, exposure to 1 and 10μmol/L Cd for 33 d reduced plant height by 18.9% and 46.4% and SPAD value by 11.2% and 31.6%, compared with control,respectively. Similarly, root length was reduced by 41.1% and 25.8% and root volume by 45.2% and 63.7%, respectively. The addition of Cd in the growth medium also had significant deleterious effect on net photosynthetic rate (Pn) and intracellular CO2concentration (Ci), with Pn being reduced by 27.2% and 62.1% at 1 μmol/L and 10 μmol/L Cd treatments compared to the control,respectively, while Ci increased correspondingly by 28.4% and 39.3%.  相似文献   

10.
A laboratory-scale trickling biofilter column,filled with Raschig rings and inoculated with Pseudomonas putida (ATCC 1785)was used to purify chlorobenzene contained waste gases.Sodium dodecyl sulfonate(SDS)was used to enhance the performance of trickling biofllter.Purification performance of the trickling biofilter was examined for chlorobenzene inlet concentration of 1.20～5.04 g/m~3 at different EBRTs between 76～153 s.Without SDS addition,with simultaneous increase in chlorobenzene inlet loading rate and gas flow rate,100% removal efficiency was achieved at EBRT of 109 s and inlet loadings below 5120 mg/m~3.Addition of SDS to nutrient solution led to improvement of trickling biofilter purification performance. By introducing 25 mg/L SDS,the removal efficiency was increased by 21% and elimination capacity up to 234 g/(m~3.h)was achieved at chlorobenzene inlet loading of 241 g/(m~3.h).Although SDS concentration experienced a low rate reduction after continuous nutrient solution recirculation,this result has little influence on trickling biofilter's removal efficiency in monitoring period.  相似文献   

11.
纳米银对黄瓜和小麦的毒性效应研究   总被引：1，自引：0，他引：1  
研究目的：研究纳米银对黄瓜和小麦的毒性及在植物中的转运和分布,探讨其毒性机制,为纳米银的环境风险评估提供科学依据。创新要点：1.选取单子叶和双子叶植物为对象,比较研究纳米银对其萌发阶段和生长阶段的毒性效应及其影响因素;2.多数研究中的纳米银均有表面修饰,本研究选择无表面修饰的纳米银材料,排除表面活性剂的干扰因素;3.以络合剂半胱氨酸掩蔽解离出的银离子,探讨纳米银颗粒对植物毒性的贡献。研究方法：通过植物根长（图2）和生物量（图3）分别评价萌发和生长阶段纳米银的植物毒性。利用电感耦合等离子体质谱（ICP-MS）测定植物组织银元素的含量（图7）。通过组织切片,利用透射电镜（TEM）观察植物根中银的微观分布（图6）。通过在暴露介质中添加半胱氨酸掩蔽银离子来评价纳米银颗粒对植物毒性的贡献（图3和5）。重要结论：在较高暴露浓度情况下,纳米银和银离子对小麦和黄瓜都具有明显的毒性。但当纳米银浓度低于200 mg/L,银离子浓度低于5 mg/L时,两者均能促进黄瓜根系的生长。两种植物在营养生长阶段比萌发阶段对纳米银的毒性更敏感。纳米银暴露后,银首先积聚于植物的根,然后被转移到地上部。为评价纳米银释放的银离子的作用,我们测定了暴露后介质中银离子的浓度。在种子萌发阶段,黄瓜和小麦的暴露液中约0.03%和0.01%的纳米银溶解,而在营养生长阶段,溶解的纳米银达到0.17%和0.06%。半胱氨酸作为银离子的强络合剂,能够彻底消除纳米银对黄瓜和小麦的作用,说明纳米银的植物效应可能来自于其释放的银离子。  相似文献   

12.
Hydroponic experiments conducted to examine the chromiun uptake by C. communis in the presence of different Cr concentrations (Cr6+ 100 and 200 mg/L, respectively) and free histidine supplementation (0.5 and 1.0 mol/L) showed that shoot and root growth of C. communis decreased greatly with increasing Cr concentrations in the medium; and that the species was a typical excluder since it accumulated high concentrations of Cr in roots but comparatively low concentrations in shoots. Chromium in shoots and roots of Cr42?-supplied plants ranged from 329–1880 and 3788–4240 mg/kg DW, respectively, while those of Cr42?-histidine-supplied plants ranged from 478 to 629 mg/kg and 4157–4303 mg/kg DW, respectively. With Cr present in the hydroponic solution, C. communis accumulated more Cr in its tissues. Increasing histidine application to the solution significantly increased chromium accumulation in the plant tissues but could not alter the accumulation pattern of plants although it induced a higher concentration of Cr in its shoots and roots. These features suggested that C. communis may serve as an alternative species in a constructed wetland for phytoextraction treatment of Cr-containing wastewater and for phytostabilization of Cr mining spoils.  相似文献   

13.
为研究硒镉联合作用对番茄根尖细胞遗传学效应,用不同硒浓度和100μmol/L镉联合处理番茄根尖24 h、48 h、72 h、96 h,统计有丝分裂指数、染色体畸变率和微核率.结果表明：单一镉处理时番茄根尖细胞有丝分裂指数下降,染色体畸变率和微核率增加,且随时间的延长而毒害加深.硒镉处理时,硒浓度低于1.0μmol/L时番茄根尖细胞有丝分裂指数增加,染色体畸变率和微核率下降,高于1.0μmol/L时番茄根尖细胞有丝分裂下降,染色体畸变率和微核率升高,但浓度过高时,微核率随着镉处理时间的延长反而有所降低,表现出低浓度硒对镉的毒害有缓解作用,高浓度硒与镉协同毒害作用.  相似文献   

14.
Hydroponic experiments conducted to examine the chromiun uptake by C. communis in the presence of different Cr concentrations (Cr6+ 100 and 200 mg/L, respectively) and free histidine supplementation (0.5 and 1.0 mol/L) showed that shoot and root growth of C. communis decreased greatly with increasing Cr concentrations in the medium; and that the species was a typical excluder since it accumulated high concentrations of Cr in roots but comparatively low concentrations in shoots. Chromium in shoots and roots of Cr24 -supplied plants ranged from 329-1880 and 3788-4240 mg/kg DW, respectively, while those of Cr24 -histidine-supplied plants ranged from 478 to 629 mg/kg and 4157-4303 mg/kg DW, respectively. With Cr present in the hydroponic solution, C. communis accumulated more Cr in its tissues. Increasing histidine application to the solution significantly increased chromium accumulation in the plant tissues but could not alter the accumulation pattern of plants although it induced a higher concentration of Cr in its shoots and roots. These features suggested that C. communis may serve as an alternative species in a constructed wetland for phytoextraction treatment of Cr-containing wastewater and for phytostabilization of Cr mining spoils.  相似文献   

15.
以金鱼为研究材料,测定了在不同浓度梯度镉及镉、锌联合胁迫下金鱼过氧化物酶与过氧化氢酶活性变化．结果表明,在镉单一毒性胁迫下其变化趋势均为先下降,然后上升．而在镉锌联合毒性胁迫下,其酶活基本都低于相应镉单一毒性下的酶活,表现为毒性协同作用．  相似文献   

16.
The simultaneous sorption behavior and characteristics of cadmium (Cd) and sulfamethoxazole (SMX) on rice straw biochar were investigated. Isotherms of Cd and SMX were well modeled by the Langmuir equation (R2 >0.95). The calculated maximum adsorption parameter (Q) of Cd was similar in single and binary systems (34129.69 and 35919.54 mg/kg, respectively). However, the Q of SMX in a binary system (9182.74 mg/kg) was much higher than that in a single system (1827.82 mg/kg). The presence of Cd significantly promoted the sorption of SMX on rice straw biochar. When the pH ranged from 3 to 7.5, the sorption of Cd had the characteristics of a parabola pattern with maximum adsorption at pH 5, while the adsorption quantity of SMX decreased with increasing pH, with maximum adsorption at pH 3. The amount of SMX adsorbed on biochar was positively correlated with the surface area of the biochar, and the maximum adsorption occurred with d 250 biochar (biochar with a diameter of 150-250 μm). Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) showed that the removal of Cd and SMX by rice straw biochar may be attributed to precipitation and the formation of surface complexes between Cd or SMX and carboxyl or hydroxyl groups. The results of this study indicate that rice straw biochar has the potential for simultaneous removal of Cd and SMX from co-contaminated water.  相似文献   

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