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171.
172.
The Influence of Mycorrhiza on Uranium and Phosphorus Uptake by Barley Plants from a Field-contaminated Soil (7 pp) 总被引:3,自引:0,他引:3
Chen B Zhu YG Zhang X Jakobsen I 《Environmental science and pollution research international》2005,12(6):325-331
Background Recent studies indicated that arbuscular mycorrhizal fungi (AMF) play important roles in plant accumulation of uranium (U)
from contaminated environments, but the impacts of fertilization practices on functioning of the symbiotic associations, which
are crucial factors influencing plant nutrition and growth responses to mycorrhiza, have rarely been considered.
Materials and Methods In a greenhouse experiment, a bald root barley mutant (brb) together with the wild type (wt) were used to test the role of
root hairs and AMF in uranium (U) uptake by host plants from a U contaminated soil. Nil, 20 and 60 mg KH2PO4-P kg–1 soil were
included to investigate the influences of phosphorus (P) fertilization on plant growth and accumulation of U.
Results Dry matter yield of barley plants increased with increasing P additions and wt produced significantly higher dry weight than
brb. Mycorrhiza markedly improved dry matter yield of both genotypes grown at nil P, whereas only brb responded positively
to mycorrhiza at 20 mg P kg-1. At the highest P level, mycorrhiza resulted in growth depressions in both genotypes, except
for the roots of wt. In general, plant P concentrations increased markedly with increasing P additions and in response to
mycorrhiza.
Mycorrhiza and P additions had no significant effects on shoot U concentrations. However, root U concentrations in both genotypes
were significantly increased by mycorrhiza. On the other hand, shoot U contents increased with increasing P levels, while
20 mg P kg-1 stimulated, but 60 mg P kg-1 marginally affected the U accumulation in roots. Root length specific U uptake was
moderately enhanced both by root hairs and strongly enhanced by mycorrhiza. Moreover, non-inoculated plants generally had
higher shoot-root ratios of U content than the corresponding inoculated controls.
Conclusion Our study shows that AMF and root hairs improves not only P acquisition but also the root uptake of U, and mycorrhiza generally
decreases U translocation from plant root to shoot. Hence, mycorrhiza is of potential use in the phytostabilization of U contaminated
environments.
Perspectives The complex impacts of P on U accumulation by barley plants suggested that U behavior in mycorrhizosphere and translocation
along the soil-fungi-plant continuum as affected by fertilization practices deserve extensive studies for optimizing the function
of mycorrhizal associations for phytoremediation purposes. 相似文献
173.
Xian T. Lu Yun Ma Cui Wang Xiao F. Zhang Da Q. Jin Chang J. Huang 《Journal of environmental science and health. Part. B》2013,48(5):445-454
Previous studies have demonstrated that pesticides could induce cytotoxicity and genotoxicity in vivo and in vitro, and that oxidative stress may be an important factor involved. However, investigations comparing the capability of different organophosphorous (OP) compounds to induce cytotoxicity, genotoxicity and oxidative stress are limited. Hence, the aim of this paper was to access the cytotoxic and genotoxic effects of five OPs or metabolites, Acephate (ACE), Methamidophos (MET), Chloramidophos (CHL), Malathion (MAT) and Malaoxon (MAO), and to clarify the role of oxidative stress, using PC12 cells. The results demonstrated that MET, MAT and MAO caused significant inhibition of cell viability and increased DNA damage in PC12 cells at 40 mg L?1. MAO was more toxic than the other OPs. ACE, MET, MAT and MAO increased the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), and decreased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) at 20 mg L?1 and 40 mg L?1 to different degrees. Pre-treatment with vitamin E(600 μM)caused a significant attenuation in the cytotoxic and genotoxic effect; pre-treatment reversed subsequent OP-induced elevation of peroxidation products and the decline of anti-oxidant enzyme activities. These results indicate that oxidative damage is likely to be an initiating event that contributes to the OP-induced cytotoxicity. 相似文献
174.
Geostatistical analyses and hazard assessment on soil lead in Silvermines area, Ireland 总被引:42,自引:0,他引:42
Spatial distribution and hazard assessment of soil lead in the mining site of Silvermines, Ireland, were investigated using statistics, geostatistics and geographic information system (GIS) techniques. Positively skewed distribution and possible outlying values of Pb and other heavy metals were observed. Box-Cox transformation was applied in order to achieve normality in the data set and to reduce the effect of outliers. Geostatistical analyses were carried out, including calculation of experimental variograms and model fitting. The ordinary point kriging estimates of Pb concentration were mapped. Kriging standard deviations were regarded as the standard deviations of the interpolated pixel values, and a second map was produced, that quantified the probability of Pb concentration higher than a threshold value of 1000 mg/kg. These maps provide valuable information for hazard assessment and for decision support. 相似文献
175.
大型蚤是一种国际公认的标准实验生物,广泛应用于污水、地表水等水质毒性检测。毒性水平较低的城市二级出水,对大型蚤往往无急性毒性效应,而具有慢性毒性效应,但慢性毒性检测周期过长,因此探索一种更灵敏的指标,实现快速检测,对于控制二级出水的水质风险具有重要意义。本研究考察了大型蚤在短期暴露于城市二级出水条件下,其体内乙酰胆碱酯酶、超氧化物歧化酶、过氧化氢酶、ATP酶、羧酸酯酶和碱性磷酸酯酶的酶活变化特征,从中筛选出对二级出水毒性响应灵敏的标志酶指标。实验结果表明,碱性磷酸酯酶、过氧化氢酶对二级出水毒性响应相对较灵敏,具有成为标志酶的潜力,研究结果为城市二级出水生物毒性评价方法优化提供新的思路。 相似文献
176.
177.
以有机固体废弃物 (废棉絮、废纸 )为原料 ,在管式炉热解反应器热解生产脱水内醚糖。研究了热解温度对热解产物相态分布的影响。同时 ,利用HPLC对脱水内醚糖的产量进行了测定。HPLC分析结果表明 :热解液水相中主要化学物质是乙酸 ,而非水相中主要化学物质是脱水内醚糖 相似文献
178.
179.
180.
O3/H2O2高级氧化技术H2O2加入量的简易控制方法 总被引:1,自引:0,他引:1
对与臭氧有着不同反应活性的3类有机污染物,探讨并建立了O3/H2O2高级氧化技术H2O2较优投加量的简易控制方法。结果表明,水中存在溶解臭氧是H2O2与臭氧降解效率具有协同作用的必要条件,另外,H2O2的较优加入量直接依赖于目标有机污染物与臭氧的反应活性。对于不同的有机物及在常规的臭氧化水处理时间内,H2O2加入量控制在单独臭氧化处理时水中溶解臭氧的20-30倍(质量比)之间为宜。这种简易控制H2O2加入量的方法对推广O3/H2O2技术在实际废水处理中的应用具有重要的意义。 相似文献