镍胁迫对玉米苗根系生长及膜保护系统的影响

[目的]研究镍(Ni<'2+>)胁迫对玉米(Zea mays L.)根系生长及膜保护系统的影响.[方法]以玉米为材料,研究了不同浓度Ni<'2+> 胁迫对玉米幼苗根系生长、根系活力及根系中超氧化物歧化酶(SOD)、过氧化物酶(POD)活性和丙二醛(MDA)含量的影响.[结果]不同浓度Ni<'2+> 处理对玉米幼苗根系具有低浓度的促进效应和高浓度的抑制效应,且随着浓度的增加抑制效应逐渐增强.根系长度、鲜重、根系活力、SOD活性、POD 活性、MDA 含量在3个处理阶段(10、30、30 d)变化趋于相同;随着玉米幼苗的生长,各项指标变化更加明显.根系活力在Ni<'2+>浓度为50 mg/kg(土)时最强,随着Ni<'2+>浓度的升高而逐渐减弱;根系保护酶系统中SOD和POD活性随着Ni<'2+>浓度的增加而呈现先升高后下降的变化趋势,在Ni<'2+>浓度为50 mg/kg(土)时出现峰值;根系细胞内MDA 含量在低Ni<'2+>浓度处理下增幅较小,Ni<'2+>浓度在100～800 mg/kg(土)时增加显著.[结论]Ni<'2+> 浓度低于50 mg/kg(土)时对玉米幼苗期根系的生长有促进作用,而超过该浓度则表现为抑制作用,Ni<'2+>浓度越高,抑制作用越明显.     

稀土元素与辣根过氧化物酶相互作用机理的论述

叙述了稀土元素的化学结构及其在农业方面的应用,系统介绍了植物辣根过氧化物酶(HRP)的结构及其在植物体内的功能,并以重稀土元素Tb(Ⅲ)为例,通过探讨其对HRP的酶活和生态毒理效应等影响的研究,对两者相互作用的可能性机理进行了研究.     

水芹水浸提液对小球藻生长及抗氧化酶活性的影响

[目的]研究水芹水浸提液对小球藻生长及其抗氧化酶活性的影响.[方法]采用小球藻在不同浓度的水芹水浸提液中纯培养的方法,测定小球藻生长速率、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性、·O2- 产生速率及丙二醛(MDA)含量的变化.[结果]10g/L水芹水浸提液处理下,SOD和POD活性逐步上升,至试验结束时都维持在较高的水平,·O2-产生速率和MDA含量与对照间无显著差异;20～50 g/L水芹水浸提液处理,藻细胞的SOD、POD活性、·O2-产生速率及MDA含量均呈先开高后降低的趋势,并且有浓度效应.[结论]水芹水浸提液对小球藻具有化惑效应.10 g/L水芹水浸提液对小球藻的生长具有明显的促进效应,20～50 g/L水芹水浸提液对小球藻有明显的克生作用.     

NdCl3对南极酵母Rhodotorula sp.NJ298抗氧化能力的影响

低浓度的NdCl3(0.1μmol·L-1～0.8 μmol·L-1)对南极酵母(Rhodotorula sp.NJ298)的抗氧化能力有促进作用.低浓度NdCl3使NJ298类胡萝卜素含量增加,SOD活力下降,CAT和POD酶活力升高,MDA含量降低,对H2O2的抗性增强.这在一定程度上提高了NJ298抗氧化能力,缓解了膜伤害,提高了其对极端环境的适应能力.     

Synthesis,fluorescence properties of Tb(Ⅲ) complexes with novel mono-substituted β-diketone ligands

Two novel pyridine-2,6-dicarboxylic acid derivatives of mono-β-diketone named methyl 6-biphenylacetyl-2-pyridinecarboxylate (MBP) and 6-biphenylacetyl-2-pyridinecarboxylic acid (BAA) and their corresponding binary complexes Tb(MBP)3.6H2O and Tb(BAA)3·6H2O were synthesized. The ligands were characterized by elemental analysis, FT-IR and 1H-NMR, and the complexes were characterized with elemental analysis, FT-IR, 1H-NMR and thermogravimetric and differential thermal analysis(TG-DTA). The investigation of fluorescence properties of the complexes Tb(MBP)3·6H2O and Tb(BAA)3·6H2O showed that the introduction of the biphenyl enlarged the π-conjugated system of the ligands and enhanced the luminescent intensity of the complexes. The Tb(Ⅲ) ion could be sensitized more efficiently by the ligands, in particular, the fluorescence intensity of the complex Tb(BAA)3·6H2O was about 20% higher than that of Tb(MBP)3·6H2O and 30% higher than that of Tb(Ⅲ) complexes with bis-β-diketone-type ligands that we have previously reported.     

Cr6+和Pb2+重金属胁迫对大蒜发芽的影响

[目的]研究Cr<'6+>和Pb<'2+>胁迫对大蒜发芽的影响.[方法]测定了在Cr<'6+>和Pb<'2+>种重金属胁迫下大蒜发芽过程中的根长、酶(SOD和CAT)活性及可溶性蛋白质含量.[结果]大蒜萌发过程中,Cr<'6+>和Pb<'2+>重金属浓度超过20 mg/L时对芽苗根长有明显的抑制作用;SOD和CAT对低浓度的重金属毒性具有一定的缓冲能力,在低浓度Cr<'6+>胁迫下SOD活性随着金属离子浓度的增加而增大,且当处理浓度为50 mg/L时达到最大,而CAT活性在Cr<'6+>浓度低于20 mg/L时逐渐增大;SOD和CAT活性在高浓度Cr<'6+>(大于50 mg/L)或在Pb<'2+>胁迫下随重金属离子浓度的增加而持续降低;在重金属(Cr<'6+>、Pb<'2+>)溶液各个浓度作用下随着时间延长可溶性蛋白质含量均表现出下降趋势,且随着浓度的提升下降趋势明显.另外,大蒜对Cr<'6+>毒性的耐受性远高于对Pb<'2+>.[结论]为深入探讨重金属对植物的毒害机制提供了理论依据.     

砷胁迫对药用植物黄芪中抗氧化酶活性的影响

[目的]探讨砷胁迫对药用植物黄芪中抗氧化酶活性的影响,以期为揭示砷毒害植物机理提供理论依据.[方法]以内蒙药用植物黄芪为材料,分别采用高锰酸钾滴定法、愈创木酚法、邻苯三酚自氧化法以及硫代巴比妥酸法研究不同浓度砷胁迫下对药用植物黄芪中过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)的活性影响以和丙二醛(MDA)的浓度变化.[结果]随着砷浓度升高,黄芪叶片中这3种酶的活性能够维持,特别是POD活性显著增加.从时间动态看,随处理时间的延长,黄芪叶片中的CAT活性先升高再降低,POD活性增加,SOD活性变化不显著;MDA含量先升后降,第8天达到最大值.[结论]该研究可为中药材重金属含量控制和药理活性鉴定提供理论依据.     

罗丹明S酶催化光度法测定过氧化氢

在pH 4.4的HAc-NaAc介质中,以辣根过氧化物酶(HRP)催化H2O2氧化KI生成I2,过量的I-与I2结合形成I3-,而I3-与罗丹明S(RhS)反应形成RhS-I3缔合微粒,该微粒导致体系在526 nm处的吸收值线性降低,据此建立了检测H2O2的分光光度分析新方法。研究了pH值,HRP,KI及RhS用量等因素对体系的影响,并对水中Cu2+,Zn2+,Ca2+,Fe3+,Mg2+,Al3+等常见离子进行了干扰试验。在最佳实验条件下,H2O2的浓度在36.72~734.4μg/L范围内与吸光度降低值呈良好的线性关系,相关系数为0.9917。方法的检出限为10μg/L。该法用于测定废水中过氧化氢,结果与纳米金光度法的结果相一致。     

PEG渗透胁迫下玉米幼苗叶片保护酶活性昼夜变化

[目的]了解逆境条件对植物体内保护酶活性昼夜变化的影响.[方法]用不同浓度聚乙二醇(PEC-6000)溶液研究渗透胁迫下玉米幼苗叶片电解质外渗率、丙二醛(MDA)含量和超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)的昼夜变化情况.[结果]一昼夜胁迫中,保护酶活性的变化不仅受PEG浓度和胁迫时间的影响,而且受先照的影响.随着光照时间和胁迫时间的延长,叶片电解质外渗率和MDA含量增加、SOD活性持续降低、POD和CAT活性的变化率则呈先增加后降低趋势;先照结束后,随着黑暗时间的延长,电解质外渗率和保护酶活性先接近对照水平,然后发生较大渡动.[结论]玉米幼苗叶片的保护酶活性变化不仅受PEG浓度、胁迫时间的影响,而且受光照的影响.     

Synthesis, characterization and enhanced luminescence of terbium complexes with 2-pyrazinecarboxylic acid and butanedioic acid by inert-fluorescent lanthanide ions

Ten solid terbium complexes with 2-pyrazinecarboxylic acid (Hpyca) and butanedioic acid (BDAH) were synthesized via coprecipitation method and characterized by elemental, EDTA titration, inductively coupled plasma (ICP), thermogravimetry-differential scanning calorimetry (TG-DSC) and infrared (IR) analyses. The results showed that the complexes had the compositions of Tb(pyca)(BDA)·2H2O, Tb0.5Y0.5(pyca)(BDA)·2H2O, Tb0.5La0.5(pyca)(BDA)·3H2O, Tb0.5Gd0.5(pyca)(BDA)·2H2O, Tb0.7Y0.3(pyca)(BDA)·3H2O, Tb0.7La0.3(pyca)(BDA)·0.5H2O, Tb0.7Gd0.3(pyca)(BDA)·H2O, Tb0.6Y0.4(pyca)(BDA)·2.5H2O, Tb0.6La0.4 (pyca)(BDA)·2.5H2O and Tb0.6Gd0.4(pyca)(BDA)·3H2O. IR spectra indicated that the rare earth ions coordinated with the carboxylic oxygen atoms of Hpyca and BDAH. Luminescence spectra showed that the doped La3+, Y3+ or Gd3+ ions did not affect the luminescence emission peak positions, but remarkably increased the luminescent intensities of terbium complexes. Furthermore, the doped lanthanide complexes showed longer luminescence lifetimes and higher quantum yields than pure terbium complex. The enhanced luminescence efficiencies of Tb3+ ions in the doped complexes might result from the antenna effect of the two carboxylate ligands as well as the decrease of the self-quench of the Tb3+ ions induced by the doped lanthanide ions.     

Kinetic and spectral studies of EHPG systems using chemi- and electrochemiluminescence methods

The systems containing EHPG, EHPG-OCH3 and EHPG-NH-Ac and Tb(Ⅲ) ions were used to study chemiluminescence (CL) and electrochemiluminescence (ECL) processes. In the CL studies the Fenton system (Fe(Ⅱ)/(Ⅲ)-H2O2) was used as a source of reactive oxygen species (ROS). Kinetic CL curves and CL spectral distributions were recorded. On the basis of the results obtained, it was demonstrated that Tb(Ⅲ) acted as a sensitizer. Similarly obtained CL decays in the systems of Fe(Ⅱ)/(Ⅲ)-EHPG (or its derivatives)-H2O2 and Fe(Ⅱ)/(Ⅲ)-EHPG (or its derivatives)-Tb(Ⅲ)-H2O2, independently on the Tb(Ⅲ) concentration, showed that the lanthanide ions did not influence the kinetics of the oxidation of EHPG (or its derivatives) in the Fenton systems. The CL intensity increased with the increasing concentration of Tb(Ⅲ) ions, which were the main emitters in the reaction systems. Spectrophotometric and luminescent studies of the systems before and after the additions of hydrogen peroxide proved that the excitation of the lanthanide ion was a result of energy transfer from the excited products of the oxidation of EHPG or its derivatives to the uncomplexed Tb(Ⅲ) ions. ECL was generated on the surface of a nonstructural modified aluminum electrode with the use of K2S2O8, H2O2 or KN3 as coreactants in aqueous solution. In these studies we employed Al electrodes covered with a 2-4 nm layer of Al2O3 doted with Tb(Ⅲ) or Dy(Ⅲ) ions. The electrodes were polarized using cathodic and anodic pulses of various amplitude and frequency. The relative ECL efficiencies were determined as a function of electric pulse parameters, electrolyte compositions and the thickness of barrier or porous layer of the Al2O3 electrode.     

Fluorescence enhancement of Tb(Ⅲ) complex with a new β-diketone ligand by 1,10-phenanthroline

A novel β-diketone, 1-(3,4,5-trisbenzyloxy)benzoyl-5-benzoyl acetylacetone (TBAA), and its corresponding binary Tb(Ⅲ) complex Tb(TBAA)3·2H2O and ternary complex Tb(TBAA)3Phen with 1,10-phenanthroline (Phen) were prepared. The ligand was characterized based on elemental analysis, FT-IR, and 1H NMR. The complexes were characterized with elemental analysis, FT-IR and thermogravimetry and derivative thermogravimetry (TG-DTG). Photoluminescence measurements indicated that the energy absorbed by the organic ligan...     

Al2 O3对连铸保护渣中氟浸出的影响

为了消除保护渣在使用过程中氟溶解到水中造成的危害,提出了开发高Al2O3含量的保护渣.研究了不同含量的Al2O3对保护渣熔渣水浸液中F-质量浓度和p H值的影响,并利用X射线光电子能谱分析了Al2O3含量对保护渣熔渣结构的影响.当Al2O3的质量分数为4%时,保护渣迁移到水中的F-质量浓度为22.8~35.4 mg·L-1,p H值的变化范围为4.0~9.5;当Al2O3的质量分数由4%增加到34%,F-质量浓度和p H值的变化范围均是先急剧减小后略有增加的趋势.X射线光电子能谱分析显示:增加保护渣中Al2O3的含量时,保护渣中Al2O3通过形成Al—F共价键,抑制了氟的浸出.控制保护渣中Al2O3的质量分数在16%~34%的范围,则实验水样中F-质量浓度在4.0~10.0 mg·L-1的范围,p H值在6.5~7.5的近中性范围,可减弱氟浸出造成的危害.     

多氯联苯对2种微藻的急性毒性研究

[目的]研究多氯联苯对海洋浮游植物的急性毒性.[方法]选择珠江口海域赤潮优势种锥状斯氏藻和热带骨条藻进行多氯联苯急性毒性试验,研究其半效应浓度(EC<,50>),分析多氯联苯对其生长以及超氧化歧化酶(SOD)和过氧化氢酶(CAT)的影响.[结果]多氯联苯对锥状斯氏藻、热带骨条藻生长有明显的抑制作用,对2种藻类的96 h半效应浓度(EC<,50>)分别为0.103和0.009 mg/L.低浓度多氯联苯对2种微藻的SOD和CAT活性有诱导作用.当多氯联苯浓度超过一定阈值,酶活性下降;与锥状斯氏藻相比,热带骨条藻对多氯联苯暴露更敏感,耐受力较差.[结论]该研究为深入研究持久性污染物对海洋浮游植物的毒性效应提供了依据.     

镉胁迫对罗汉果幼苗生理生化特性的影响

[目的]研究不同浓度Cd胁迫对罗汉果幼苗生理生化特性的影响.[方法]通过盆栽试验,测定不同浓度Cd处理的罗汉果幼苗细胞膜透性,MDA、脯氨酸和可溶性糖含量,以及SOD、POD、CAT活性等各项生理生化指标.[结果]随着Cd浓度升高,细胞膜透性逐渐增大;在相对低浓度Cd(10 mg/kg)处理下 MDA、脯氨酸和可溶性糖含量均少于对照,而后随着Cd浓度的升高而明显上升;在较低Cd浓度胁迫条件下,SOD、POD、CAT活性变化不明显,但随着Cd浓度的升高,SOD、POD、CAT活性逐渐升高,然后又降低.[结论]高浓度Cd胁迫加重了叶片氧化程度并对罗汉果生长具有一定的抑制作用;而SOD、POD、CAT 活性的提高与维持是罗汉果耐Cd 胁迫的物质基础之一.     

NaCl胁迫对藜幼苗叶片渗透调节物质和保护酶的影响

[目的]研究不同浓度NaCl胁迫对纂叶片中渗透调节物质和保护酶活性的影响,以探讨黎的耐盐机理,为藜的人工栽培及推广提供理论依据.[方法]待藜幼苗长到4叶期时,用0%、0.6%、1.2%、1.8%NaCl溶液进行根部胁迫处理,分别于处理0、1、3、5、7 d后从藜幼苗上部取第3～5片功能叶片进行各项生理指标的测定.[结果]在0.6%Nacl胁迫下,渗透调节物质(可溶糖、脯氨酸和可溶性蛋白质)含量和保护酶(SOD、POD和CAT)活性都是缓慢增加的.丙二醛含量增加不大,膜脂过氧化水平低.在1.2%、1.8%NaCl胁迫下,渗透调节物质(可溶性糖、脯氨酸和可溶性蛋白质)含量随胁迫时间的延长而增加,SOD、POD、CAT活性随胁迫时间的延长先升高后降低,丙二醛含量显著提高,膜脂过氧化水平增大.[结论]藜可以通过渗透调节物质增加和保护酶活性增大来对适度的盐胁迫有一定的适应性,但高浓度、长时间的盐胁迫会对藜造成严重损伤.     

茼蒿不同器官水浸提液对西瓜幼苗生长及酶活性的影响

[目的]初步探讨茼蒿对西瓜枯萎病化感作用机理.[方法]以"京欣1号"西瓜品种为材料,探讨了干制茼蒿不同器官浸提液对西瓜幼苗生长、过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量的影响.[结果]浓度为0.001 g/ml的茼蒿不同器官(花、茎叶、根)浸提液对西瓜幼苗生长均有促进作用;并能提高POD、CAT、SOD活性,降低MDA含量;茎叶浸提液效果最强,花浸提液效果最弱.[结论]采用茼蒿与西瓜套种的方式在生产上能克服西瓜的连作障碍.     

Metal-organic frameworks of lanthanide iminodiacetates and tartrates:Synthesis,structural characterization and luminescence properties——Commemorating the 100th anniversary of the birth of Academician Guangxian Xu

Two series of lanthanide-containing metal-organic frameworks(Ln-MOFs) of the general formula{[Ln(HIDA)_2 H_2 O]ClO_4·H_2 O}_n(Ln = La(1),Nd(2),Eu(3),Gd(4),Tb(5),Eu:Tb(6);H_2 IDA=iminodiacetic acid) and [Ln(TT)(HTT)(H_2 O)_3]_n(Ln=Eu(7),Gd(8),Tb(9),Dy(10),and Eu:Tb(11);H_2 TT=tartaric acid)were synthesized by reacting Ln(ClO_4)_3 with iminodiacetic acid and L-tartaric acid,respectively.All compounds were structurally characterized by single-crystal X-ray diffraction.Elemental analyses are co nsistent with the corre sponding crystallographically generated formulas.Mo reover,the luminescence properties of both the single and mixed-lanthanide complexes were studied.Near infrared,red,and green emissions that are characteristic of Nd(Ⅲ),Eu(Ⅲ),and Tb(Ⅲ) are observed for 2,3/7,and 5/9,respectively.For the two mixed-lanthanide complex systems 6 and 11,depending on the relative amount of Eu(Ⅲ) and Tb(Ⅲ),the color of emission can be fine-tuned.It is found that a small amount of Eu(Ⅲ) is adequate for the observation of the most intense transition of Eu(Ⅲ).This is believed to be a result of energy transfer from Tb(Ⅲ) to Eu(Ⅲ) within the same complex-a conclusion supported by the significantly shortened lifetime of Tb(Ⅲ) and the accompanying enhanced lifetime of Eu(Ⅲ) in the mixedlanthanide complex with respect to the corresponding values for the pure Tb(Ⅲ) and Eu(Ⅲ) complexes with the same ligand.     

铅胁迫对红花檵木生理特性的影响

[目的]研究铅胁迫对红花框木生理特性的影响.[方法]以红花檀木为材料,采用水培方法,对不同Pb<'2+>浓度(0、100、500、1 000、1 500mg/L)和处理时间(8、16 d)胁迫下植物的叶片超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、相对电导率以及可溶性糖含量的变化进行了研究.[结果]在Pb<'2+>胁迫下,随Pb<'2+>处理浓度的增加红花檀木叶片中的SOD活性先增加后降低;MDA含量和相对电导率在Pb<'2+>胁迫下有不同程度的增加;可溶性糖含量在Pb<'2+>胁迫下出现上升,其可能是使红花檀木提高诱导胁迫抗性的调节物质之一.[结论]初步揭示了不同浓度Pb<'2+>对红花檀木生理生化代谢的影响,为进一步探讨Pb<'2+>胁迫下红花檀木生理特性与Pb<'2+>耐性能力的相关关系奠定了基础.     

Pb胁迫对柳树根系形态和生理特性的影响

[目的]评价柳树对重金属Pb的忍耐能力及应用于植物修复的潜力.[方法]采用溶液培养研究了不同浓度Pb胁迫对苏柳172和垂柳2种柳树的根系形态、根系活力以及叶片保护酶活性和渗透调节物质的影响.[结果]Pb处理显著抑制2种柳树的根系伸长,垂柳根系表面积、根体积、根平均直径先增后降,苏柳172根系表面积、根体积、根平均直径均受到Pb的显著抑制.2种柳树的根系活力均下降:超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性和脯氨酸(Pro)含量均先增加后下降;可溶性蛋白含量、叶绿紊含量在一定程度内均降低,只是变化的幅度和进程不同.[结论]为柳树应用于重金属修复具有重要的参考价值.