植物对铜的吸收运输及毒害机理研究进展

铜是植物生长发育必需的微量元素,但过量的铜对植物有毒害效应。因而植物体在长期的进化过程中形成了一套内稳态机制来调控铜离子在细胞中的浓度;既能满足细胞正常代谢对铜的需求又要使细胞免受铜毒害。植物对铜内稳态机理主要涉及植物对铜运输、螯合和区室化作用等方面,以此来达到对铜离子的吸收、分配和解毒的功能。本文综述了植物对铜的吸收运输与解毒的最新进展。     

Leaf position and genotype differences for mineral element concentrations in sorghum grown on tropical acid soil 1

Mineral element deficiencies and toxicities are common problems associated with sorghum [Sorghum bicolor (L.) Moench] production on acid soils. To better understand some of the mineral element problems and the analysis of plant tissue of sorghum plants grown on acid soils, four sorghum genotypes were grown on an acid Oxisol at Carimagua, Colombia limed with dolomite at 2 and 6 Mg ha^‐1.

Samples for mineral element analyses were obtained from leaves at different positions on the four genotypes. Concentrations of P and Mg were highest in the flag leaf (Leaf No. 1) and decreased as the position on the plant declined from the top of the plant for plants grown at 2 Mg lime ha^‐1. Similar decreases in P, Mg, K, and Zn concentrations occurred in plants grown with 6 Mg lime ha^‐1. Concentrations of Ca, S, Si, Mn, Fe, Cu, and Al increased as leaf position declined from the flag leaf for plants grown at 2 and 6 Mg lime ha^‐1. The higher lime supply enhanced Ca and reduced Mn and Fe concentrations in leaves. Differences in mineral element concentrations for the four genotypes used were fairly extensive. The elements to show the greatest range among genotypes were Al and Si and the elements to show the least range among genotypes were P, K, and S. Care should be used in collecting leaf samples for plant analysis and genotypic differences for accumulation of mineral elements should be considered in interpretation of results.     

Therapeutic management of copper deficiency in buffalo heifers: Impact on immune function

To evaluate the magnitude of copper deficiency in Northern India and to examine the various haematobiochemicals, enzymes, vitamins and immune functions affected by copper deficiency, and to identify the parameters which can be of diagnostic importance in copper deficiency, a survey was conducted in 12 districts of Northern India. Significant deficiency of copper was observed in soil, fodder and serum samples of buffalo heifers. Fifty hypocuperaemic buffalo heifers were selected from these areas and were randomly divided into two groups, A and B. The heifers in group A were provided with mineral mixture containing copper sulphate and in group B without copper sulphate. Significant (p < 0.01) improvement in serum ceruloplasmin level was observed within 30 days of treatment, while significant (p < 0.01) improvement in monoamine oxidase and liver cytochrome oxidase was observed at the 60th day of treatment in group A animals. Significant improvement was observed in T₃ and T₄, in the animals of group A within 60 days of treatment. The values of vitamin A and E showed significant (p < 0.01) improvement within 30 days of treatment. The phagocytic activity of neutrophils against Candida albicans significantly (p < 0.01) improved in group A within 60 days of treatment. Similarly, significant improvement in superoxide dismutase activity in red blood cells was observed at the 30th day, and in total leukocytes and whole blood at the 60th day in group A animals. Significant improvement in liver copper level was observed at the 30th day of treatment, while in group B the liver copper was significantly (p < 0.01) depleted at the 60th day of experimentation. Additional copper supplementation improved growth performance significantly in group A.     

Changes in oxidative stress indices, zinc and copper concentrations in blood in canine demodicosis

Status of certain oxidative stress indices and zinc and copper concentrations in blood were estimated in dogs with localized demodicosis (LD) and generalized demodicosis (GD). In comparison to healthy control, erythrocytic lipid peroxides level and superoxide dismutase activity were significantly (P < 0.01) higher in both LD as well as GD. However, level of reduced glutathione and activity of catalase were significantly (P < 0.01) lower in both LD and GD. Blood zinc and copper levels in dogs with LD and GD were significantly (P < 0.01) lower than healthy control. Significant (P < 0.01) differences were also observed in different oxidative stress indices and zinc and copper levels in between LD and GD groups. From the present study, it was concluded that demodicosis is associated with oxidative stress and antioxidant supplementation may be beneficial in management of canine demodicosis.     

我国高校大学生评教理论综述

伴随高等教育大众化进程及教学改革的深入,学生评教工作开始在国内推广。为保障学生评教工作的有效实施,我国学者对此做了大量的研究。通过对1991年￣2010年国内研究文献的梳理,发现国内学者对评教价值、评教权的定位、效度与信度及影响因素等给予了高度的关注,并就学生评教提出了各自的改进意见。     

龙须菜对水体Cu2+、Cd2+的去除效率及其生理响应

通过室内实验,研究了龙须菜对水体Cu^2＋、Cd^2＋的去除效率及其部分生理生化指标的变化状况。结果显示,龙须菜对水体低浓度（0．05mg／L）Cu^2＋、Cd^2＋的去除率分别达到了99．9％和93．1％;对较高浓度（0．5mg／L）Cu^2＋、Cd^2＋的去除率分别为55．24％和86．15％;水体较高浓度（0．5mg／L）Cu^2＋会导致龙须菜叶绿素a、b和藻红素的含量均显著下降（P〈0．05）,而高浓度（2．5mg／L）Cd^2＋不会导致色素含量的显著下降;龙须菜对环境中Cu^2＋的生理响应浓度也明显小于Cd^2＋,藻体SOD活性出现峰值且MDA含量显著高于（P〈0．05）对照组的浓度水平分别为Cu^2＋0．05mg／L及Cd^2＋0．5mg／L。龙须菜更适宜作为对海水Cd^2＋污染进行生物修复的植物。     

污染砂质土壤酸化对铜和锌释放影响的模拟研究

砂质土壤上造林会引起土壤酸化,影响铜和锌的释放。本文用模拟方法研究了砂质耕地造林引起土壤酸化对土壤中铜和锌释放的影响。结果表明,酸化可明显改变土壤中铜和锌的化学形态,促使碳酸盐结合态铜和锌向交换态、有机质结合态和氧化物结合态形式转化,增加土壤铜锌的释放和淋出潜力,其中对锌的影响尤为明显。铜和锌溶解度明显增加的土壤 pH 分别为 3.8-4.5和 6.2-6.5。图3表2参14。     

Uptake and Translocation of Copper in Brassicaceae

Abstract

Ten cvs. of four Brassicaceae species were tested to evaluate their copper (Cu) uptake and translocation. Germination and root length tests indicated that Brassica juncea cv. Aurea and Raphanus sativus cvs. Rimbo and Saxa were the species with the highest germinability and longest roots at Cu concentrations ranging from 25 up to 200 µM. Raphanus sativus cv. Rimbo grown in hydroponic culture at increasing Cu concentrations (from 0.12 up to 40 µM) for 10 days produced a relatively high biomass (17.2 mg plant^?1) at the highest concentration and had a more efficient Cu translocation (17.8%) in comparison with cvs. Aurea and Saxa. The potential of cv. Rimbo for Cu uptake was then followed for 28 days at 5, 10, and 15 µM Cu. In comparison with the control, after 28 days of growth the 15 µM Cu‐treated plants showed a reduction in the tolerance index (?40%) and in the above‐ground dry biomass (?19%). On the contrary, an increase in the below‐ground dry weight was observed (+35%). Copper accumulated during the growth period both in the below‐ and above‐ground parts (about 14 and 4 µg plant^?1 at 10 and 15 µM Cu, respectively), but the translocation decreased from 50 to 30% in the last week at all the concentrations used. In addition, cv. Rimbo grown in a multiple element [cadmium (Cd), chromium (Cr), Cu, lead (Pb), and zinc (Zn)] naturally‐contaminated site accumulated all elements in the above‐ground part in a range from 5 to 62 µg plant^?1.     

腐殖酸?高岭土?铜在多孔介质中的迁移及相互作用

[目的]控制重金属在地下水深处污染。[方法]采用静态吸附试验和动态模拟试验比较了腐殖酸和高岭土对铜的吸附及其在多孔介质中的迁移。[结果]铜的存在抑制了高岭土在多孔介质中的迁移,高岭土胶体在多孔介质中沉积量增大,导致高岭土对铜的迁移促进作用不明显,腐殖酸降低了胶体沉积的同时促进了铜的迁移,在动态迁移过程中腐殖酸和高岭土对铜产生了竞争吸附,同时高岭土占据了腐殖酸在石英砂上的吸附点位,促进了腐殖酸的迁移。[结论]减少地下水中腐殖酸含量可以降低重金属在地下水深处的富集。     

Application of High Copper and Zinc Compost and Its Effects on Soil Properties and Growth of Barley

Abstract

A compost of high copper (Cu) and zinc (Zn) content was added to soil, and the growth of barley (Hordeum vulgare L.) was evaluated. Four treatments were established, based on the addition of increasing quantities of compost (0, 2, 5, and 10% w/w). Germination, plant growth, biomass production, and element [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), iron (Fe), Cu, manganese (Mn), and Zn] contents of soil and barley were determined following a 16‐week growing period. Following harvesting of the barley, analysis of the different mixtures of soil and compost was performed. Micronutrient contents in soils as affected by compost additions were determined with diethylene–triamine–pentaacetic acid (DTPA) (Cu, Mn, Fe, and Zn) or ammonium acetate [Ca, Na, Mg, K, cation exchange capacity (CEC)] extractions, and soils levels were compared to plant uptake where appropriate. Increasing rates of compost had no affect on Ca, Mg, or K concentration in barley. Levels of Cu, Zn, Mn, and Na, however, increased with compost application. High correlations were found for DTPA‐extractable Cu and Zn with barley head and shoot content and for Mn‐DTPA and shoot Mn content. Ammonium acetate–extractable Na was highly correlated with Na content in the shoot. High levels of electrical conductivity (EC), Cu, Zn, and Na may limit utilization of the compost.