镍处理对水稻叶片H_2O_2 积累和抗病的诱导效应

2 .2 0mmol/L的硝酸镍处理水稻幼苗后第 3天用稻白叶枯菌 (Xanthomonasoryzaepv .oryzae)挑战接种 ,硝酸镍处理的稻苗病情比对照明显减轻 ,并且叶片中过氧化物酶 (POD)活性上升 ,过氧化氢酶 (CAT)和抗坏血酸过氧化物酶 (APX)活性明显下降 ,H2 O2 和丙二醛 (MDA)含量显著增加。这些结果表明 ,H2 O2 积累与镍诱导的抗病作用密切有关     

渗透胁迫对山黧豆幼苗H2O2及毒素积累的影响

用PEG经根部处理15d龄的山黧豆幼苗,取幼苗叶片为实验材料,测定过氧化氢酶(CAT)、过氧化物酶(POD)活性、过氧化氢(H     

镍处理对水稻叶片H2O2积累和抗病的诱导效应

2.20mmol/L的硝酸镍处理水稻幼苗后第3天用稻白叶枯菌（Xanthomonas oryzae pv.oryzae）挑战接种,硝酸镍处理的稻苗病情比对照明显减轻,并且叶片中过氧化物酶（POD）活性上升,过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）活性明显下降,H2O2和丙二醛（MDA）含量显著增加。这些结果表明,H2O2积累与镍诱导的抗病作用密切有关。     

山黧豆根系对H2O2诱导氧化胁迫的生理应答

以水培7d苗龄的山黧豆幼苗为材料,向水培溶液中施加不同浓度H2O2处理山黧豆幼苗24h,分析山黧豆根系受氧化胁迫的程度与抗氧化系统的应答特征,以揭示山黧豆对氧化胁迫的耐受机制。结果显示:(1)随外源H2O2处理浓度的不断增加,山黧豆幼苗侧根的数目无显著变化,而其根的鲜重则显著降低。(2)同时,根系组织的内源H2O2染色范围和程度显著增高,但根尖区域始终保持较低水平的H2O2;相反,O-·2染色范围和程度明显减少,根尖区域却始终保持较高水平的O-·2。(3)同期根系抗坏血酸(ASC)含量及过氧化氢酶(CAT)、过氧化物酶(POD)与抗坏血酸过氧化物酶(APX)的活性均表现出了先升高后降低的趋势,而超氧化物歧化酶(SOD)一直表现为持续上升的趋势。研究表明,在外源H2O2胁迫条件下,山黧豆根系O-·2的积累可能与其生长和活力呈正相关,而根系H2O2的积累则与其受氧化胁迫程度呈正相关;低浓度的H2O2处理可以提高山黧豆抗氧化系统对体内活性氧的清除能力。     

蚕豆监测大气SO2污染的指标筛选研究

熏气和暴露试验表明,蚕豆叶片可见伤害症状不宜作为监测指标,超氧化物歧化酶(SOD)活性、抗坏血酸(ASA)含量和游离氨基酸(AA)含量作为监测指标,其指示效果优于过氧化物酶(POD)活性和叶绿素含量,其中又以SOD活性为最好,而根据以上5个指标综合评价的效果又要优于任何单个指标。     

纳米TiO2、ZnO、SiO2对剑尾鱼肝组织中Na+/K+-ATP酶活性的影响

采用浸浴法研究了氧化纳米颗粒TiO2、ZnO、SiO2对剑尾鱼(Xiphophorus helleri)肝中Na+/K+-ATP酶活性的影响。结果表明:纳米TiO2处理组,高浓度(5 mg/L、10 mg/L)组表现为抑制作用,其中5 mg/L处理组Na+/K+-ATP酶的活性与对照组无显著差异(p>0.05),10 mg/L处理组中Na+/K+-ATP酶的活性显著低于对照组中酶的活性(p<0.05)。低浓度组(0.1 mg/L、1 mg/L)则表现为先诱导后抑制,除0.1 mg/L组在暴露1 d后与对照组有显著差异外(p<0.05),其余组与对照组均无显著差异(p>0.05)。纳米ZnO、SiO2处理组(0.1 mg/L、10 mg/L)在暴露1 d后,肝中Na+/K+-ATP酶的活性均比对照组高,随着暴露时间增加至20 d,Na+/K+-ATP酶活性下降,且显著低于对照组(p<0.05)。3种纳米颗粒的浓度为0.1 mg/L时,对暴露后1 d剑尾鱼肝中的Na+/K+-ATP酶活性的影响均为诱导作用,诱导大小顺序为ZnO>TiO2>SiO2;随着暴露时间的增加至10 d,纳米TiO2、ZnO、SiO2处理组对Na+/K+-ATP酶活性均表现出抑制作用。     

外源H2O2对盐胁迫下小麦幼苗生理指标的影响

以‘郑麦-004’小麦幼苗为供试材料,采用Hoagland营养液培养方法,通过添加H2O2的清除剂过氧化氢酶(CAT)和抗坏血酸(ASA),研究0.05μmol/L外源H2O2处理对150mmol/L NaCl胁迫下小麦幼苗生长和抗氧化系统活性的影响,探讨低浓度外源H2O2对盐胁迫下小麦幼苗伤害的防护作用及其生理机制。结果显示:外源H2O2能缓解盐胁迫对小麦幼苗生长的抑制效应,降低丙二醛(MDA)含量和超氧自由基(O2.-)的产生速率,使小麦幼苗的株高、根长和干重均显著增加,并能提高超氧化物歧化酶(SOD)、过氧化物酶(POD)、CAT、抗坏血酸氧化酶(APX)等保护酶活性和抗氧化物质谷胱甘肽(GSH)的含量;而H2O2清除剂(CAT和AsA)能够逆转外源H2O2对盐胁迫下小麦幼苗生长的促进作用。研究表明,低浓度外源H2O2处理能促进小麦幼苗中的酶类和非酶类抗氧化剂的产生,减少脂质过氧化物的含量,提高小麦幼苗的耐盐性。     

CO2浓度升高对三种地被类观赏竹生理特性的影响

运用开顶式气室(OTCs)模拟大气CO₂浓度升高(500、700 μmol·mol^-1)情景,以环境背景大气为对照,研究CO₂浓度升高对3种地被类观赏竹(美丽箬竹、黄条金刚竹和白缟椎谷笹竹)叶片的膜脂过氧化和抗氧化系统的影响及其种间差异.结果表明: 试验进行103 d后,500 μmol·mol^-1CO₂浓度下,3种地被类观赏竹的叶片超氧阴离子含量、丙二醛(MDA)含量、相对电导率和可溶性糖含量总体上没有发生明显的变化,但叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性有一定程度的改变;700 μmol·mol^-1 CO₂浓度下,3个竹种的叶片MDA含量和相对电导率没有发生明显变化,但对叶片超氧阴离子含量、可溶性糖含量和SOD、POD、CAT、APX活性的影响较为明显.不同竹种对CO₂浓度升高环境的适应能力为美丽箬竹＞黄条金刚竹＞白缟椎谷笹竹.     

油桃花芽破眠过程中H2O2代谢与Ca2+转运的关系

利用化学测定法分析高温、单氰胺和TDZ 3种破眠处理对"曙光"油桃休眠花芽H2O2代谢的主要影响,利用非损伤微测技术检测H2O2对休眠芽Ca2+转运的影响,研究H2O2在芽休眠解除过程中的调控作用.结果表明:在深休眠时期,高温和单氰胺处理均能诱导芽内H2O2含量升高和过氧化氢酶(CAT)活性降低,并具有显著的破眠作用;TDZ对H2O2含量及CAT、过氧化物酶(POD)活性影响不大,破眠效果较差.休眠花芽原基组织钙通道活跃,对外源Ca2+呈吸收状态.外源H2O2可诱导休眠花芽原基组织Ca2+转运发生变化,低浓度H2O2降低Ca2+吸收速率,高浓度H2O2使组织对Ca2+的转运由吸收转变为释放.这表明休眠芽内H2O2信号和Ca2+信号相关联,通过诱导H2O2积累调控Ca2+信号可能在高温和单氰胺打破休眠的信号转导过程中起重要作用.     

胁迫诱导谷胱甘肽还原酶活性和同工酶谱的变化与H2O2的关系（英文）

以多种胁迫处理的野生型水稻中花11及其携带谷胱甘肽转移酶(GST)和过氧化氢酶(CAT)的功能获得突变体为材料,分析地上部H2O2含量、谷胱甘肽还原酶(GR)活性和同工酶谱的变化.结果显示,胁迫条件下野生型水稻(W)中H2O2的含量明显高于其突变体(M).非胁迫条件下W和M的GR同工酶都有3条带,且W和M之间无显著差异.单一镉、PEG-6000和外源H2O2处理诱导W均产生1条额外谱带,用H2O2和抗坏血酸(AsA)同时处理时,W中则未见该条带.当用镉和CAT抑制剂复合处理时,W和M的所有同工酶活性都降低;而同时用镉和H2O2清除剂处理时,W中则无GR同工酶条带.在其他处理(盐、高温、Zn、盐+高温、镉+高温、PEG+高温和Cd+Zn)条件下,W和M的GR活性和/或同工酶谱的变化也有明显差别.在所有处理中,W和M的GR总酶活性的变化与其同工酶的活性变化基本一致.在胁迫条件下W和M积累H2O2的水平不同,其GR活性和/或同工酶谱的变化也存在明显差异.研究表明,不同环境胁迫诱导水稻GR活性和同工酶谱的变化可能与H2O2水平有关.     

Effects of catalase on the accumulation of H2O2 in rice cells inoculated with rice blast fungus, Magnaporthe oryzae

Roles of H₂O₂ in the infection process of Magnaporthe oryzae on rice were investigated. In a leaf sheath assay for up to 48 h post-inoculation, the absence or presence of catalase in the conidia suspension was correlated with the level of accumulated H₂O₂ in infected leaf cells, as observed by staining with 3',3-diaminobenzidine tetrahydrochloride. In the incompatible interaction, the appearance of autofluorescence or frequency of cell death characterized by granulation (symptoms characteristic of hypersensitive responses) was not significantly affected by the presence of catalase in the conidia suspension. In the leaf blade assay, inoculation of compatible conidia in the presence of catalase produced more severe symptoms than that of conidia in the absence of catalase at 6 days post-inoculation. These results suggest that, in this host–parasite interaction, the primary role of host-produced H₂O₂ is in limiting hyphal growth after penetration through toxic action. Furthermore, in incompatible interactions, H₂O₂ is implied not to be a major mediator of hypersensitive cell death.     

New preparations and molecular structures of cis-MCl2(Ph2PCH2PPh2)2, M = Ru,Os and trans-RuCl2(Ph2PCH2PPh2)2

The title compounds were made by reacting bis(diphenylphosphino)methane (dppm) with reduced solutions of OsCl₆^4? and Ru₂OCl₁₀^4?. The crystal and molecular structures of these compounds have been determined form three-dimensional X-ray study. The cis-isomers crystallize with one CHCl₃ per molecule of the complex. All three compounds crystallize in the monoclinic space group P2₁/n with unit cell dimensions as follows: Cis-OsCl₂(dppm)₂·CHCl₃: a = 13.415(4) Å, b = 22.859(4) Å, c = 16.693(3) Å, β = 105.77(3)°, V = 4926(3) ų, Z = 4. cis-RuCl₂(dppm)₂·CHCl₃: a = 13.442(3) Å, b = 22.833(7) Å, c = 16.750(4) Å, β = 105.53(2)°, V = 4953(3) ų, Z = 4. trans-RuCl₂(dppm)₂: a = 11.368(7) Å, b = 10.656(6) Å, c = 18.832(12) Å; β = 103.90(6)°, V = 2213(7) ų; Z = 2. The structures were refined to R = 0.044 (R_w = 0.055) for cis-OsCl₂(dppm)₂·CHCl₃; R = 0.065 (R_w = 0.079) for cis-RuCl₂(dppm)₂·CHCl₃ and R = 0.028 (R_w = 0.038) for trans-RuCl₂(dppm)₂. The complexes are six coordinate with stable four-membered chelate rings. The PMP angle in the chelate rings is ca. 71° in each case.     

Crystal structures of MoCl2(O)(O2)(OPMePh2)2 and mixtures of MoCl2(O2)(OPPh3)2 and MoCl2(O)(O2)(OPPh3)2: allylic alcohol isomerization studies using MoCl2(O)(O2)(OPMePh2)2

Adding one equivalent of H₂O₂ to compounds of stoichiometry MoCl₂(O)₂(OPR₃)₂, OPR₃ = OPMePh₂ or OPPh₃, leads to the formation of oxo-peroxo compounds MoCl₂(O)(O₂)(OPR₃)₂. The compound MoCl₂(O)(O₂)(OPMePh₂)₂ crystallized with an unequal disorder, 63%:37%, between the oxo and peroxo ligands, as verified by single-crystal X-ray diffractometry, and can be isolated in reasonable yields. MoCl₂(O)(O₂)(OPPh₃)₂, was not isolated in pure form, co-crystallized with MoCl₂(O)₂(OPPh₃)₂ in two ratios, 18%:82% and 12%:88%, respectively, and did not contain any disorder in the arrangement of the oxo and peroxo groups. These complexes accomplish the isomerization of various allylic alcohols. A mechanism of this reaction has been constructed based on ¹⁸O isotopic studies and involves exchange between the alcohol and metal bonded O atoms.     

Achiral internucleoside linkages: CH2-CH2-NH and nH-CH2-CH2 linkages

The synthesis of CH₂-CH₂-NH and NH-CH₂-CH₂ internucleoside linkages are described. Antisense oligonucleosides containing these dimer modifications hybridized to the sense sequence. Furthermore incorporation of these backbone modifications enhanced the nuclease resistance of the antisense strand.     

Selective synthesis of triangular cluster oxido-sulfidocomplexes of Mo and W: High yield preparations of [Mo3O2S2(H2O)9], [W3O2S2(H2O)9], [W2MoO2S2(H2O)9] and their derivatization

Reaction of [Mo₂O₂(μ-S)₂(H₂O)₆]²⁺ with Mo(CO)₆ or metallic Mo under hydrothermal conditions (140 °C, 4 M HCl) gives oxido-sulfido cluster aqua complex [Mo₃(μ₃-S)(μ-O)₂(μ-S)(H₂O)₉]⁴⁺ (1). Similarly, [W₃(μ₃-S)(μ-O)₂(μ-S)(H₂O)₉]⁴⁺ (2) is obtained from [W₂O₂(μ-S)₂(H₂O)₆]²⁺ and W(CO)₆. While reaction of [Mo₂O₂(μ-S)₂(H₂O)₆]²⁺ with W(CO)₆ mainly proceeds as simple reduction to give 1, [W₂O₂(μ-S)₂(H₂O)₆]²⁺ with Mo(CO)₆ produces new mixed-metal cluster [W₂Mo(μ₃-S)(μ-O)₂(μ-S)(H₂O)₉]⁴⁺ (3) as main product. From solutions of 1 in HCl supramolecular adduct with cucurbit[6]uril (CB[6]) {[Mo₃O₂S₂(H₂O)₆Cl₃]₂CB[6]}Cl₂⋅18H₂O (4) was isolated and structurally characterized. The aqua complexes were converted into acetylacetonates [M₃O₂S₂(acac)₃(py)₃]PF₆ (M₃ = Mo₃, W₃, W₂Mo; 5a-c), which were characterized by X-ray single crystal analysis, electrospray ionization mass spectrometry and ¹H NMR spectroscopy. Crystal structure of (H₅O₂)(Me₄N)₄[W₃(μ₃-S)(μ₂-S)(μ₂-O)₂(NCS)₉] (6), obtained from 2, is also reported.     

Solution-mediated syntheses and characterizations of two new zincophosphites [C6H14N2]0.5[Zn(H2PO3)2] and [C4H12N2]0.5[(CH3)2NH2][Zn2(HPO3)3]

Two new zincophosphites [C₆H₁₄N₂]_0.5[Zn(H₂PO₃)₂] 1 and [C₄H₁₂N₂]_0.5[(CH₃)₂NH₂][Zn₂(HPO₃)₃] 2 have been solvothermally synthesized in mixed solvents of N,N-dimethylformamide (DMF) and 1,4-dioxane (DOA), respectively. Single-crystal X-ray diffraction analysis reveals that compound 1 exhibits a neutral inorganic chain formed by ZnO₄ and HPO₂(OH) units. Interestingly, the left- and right-handed hydrogen-bonded helical chains are alternately formed via the hydrogen-bonds between two adjacent chains. Compound 2 exhibits a layer structure with 4- and 12-MRs formed by ZnO₄ and HPO₃ units, in which two kinds of organic amine molecules both act as countercations to compensate the overall negative electrostatic charge of the anionic network.     

Spectroscopic and electrochemical properties of a new nitrosyl-complex of Ru(II): trans-[Ru(NO){(CH3CH2)2PCH2CH2P(CH2CH3)2}2Cl](PF6)2

A new ruthenium nitric oxide complex with the bidentate phosphine, 1,2-bis(diethylphosphino)ethane (depe), has been synthesized and characterized by UV-Vis, infrared, EPR, NMR, electrochemical techniques and X-ray structure determination. The electronic spectrum showed a typical band of dπ→pπ* charge-transfer (CT) transition, assigned to Ru(II)NO transition, and the vibrational spectrum exhibited a peak of nitrosyl ligand at (ν_NO=1851 cm⁻¹). A model structure for this complex has been proposed based on ¹H, ¹H{³¹P}, ³¹P{¹H}, ¹³C{¹H}, COSY ¹H¹H{³¹P}, J-Resolved, HSQC, HMBC, HSQC ¹H¹³C{³¹P} and ¹H¹³C HSQC/¹H¹H TOCSY spectral data, and confirmed by X-ray diffraction. The nitrosonium character for the NO ligand become evident through both electron paramagnetic resonance and X-ray data (angle RuNO=177.4(3)°). The reversible monoeletronic process at E_1/2=0.040 V versus SHE was assigned to the ligand NO⁺/NO redox couple. Under treatment with Cd(Hg) solutions containing the [Ru(NO)(depe)₂Cl](PF₆)₂ yields a signal in the EPR spectrum (g_⊥=1.99 and g_//=1.88) which fitted quite well with the simulated spectra of coordinated NO species.     

Synthesis of tantalum and niobium complexes that contain the diamidoamine ligand, [(3,4,5-F3C6H2NCH2CH2)2NMe], and the triamidoamine ligand, [(3,5-Cl2C6H3NCH2CH2)3N]

Several niobium and tantalum compounds were prepared that contain either the diamidoamine ligand, [(3,4,5-F₃C₆H₂NCH₂CH₂)₂NMe]²⁻ ([F₃N₂NMe]²⁻), or the triamidoamine ligand, [(3,5-Cl₂C₆H₃NCH₂CH₂)₃N]³⁻ ([Cl₂N₂NMe]³⁻). The former include [F₃N₂NMe]TaCl₃, [F₃N₂NMe]NbCl₃, [F₃N₂NMe]TaMe₃, [F₃N₂NMe]NbMe₃, [(F₃N₂NMe)TaMe₂][MeB(C₆F₅)₃], [F₃N₂NMe]Ta(CHSiMe₃)(CH₂SiMe₃), [F₃N₂NMe]Ta(CH₂-t-Bu)Cl₂, [F₃N₂NMe]Ta(CH-t-Bu)(CH₃), and [F₃N₂NMe]Ta(η²-C₂H₄)(CH₂CH₃). The latter include [Cl₂N₂NMe]TaCl₂, [Cl₂N₂NMe]TaMe₂, [Cl₂N₂NMe]Ta(η²-C₂H₄), and [Cl₂N₂NMe]Ta(η²-C₂H₂).X-ray diffraction studies were carried out on [F₃N₂NMe]Ta(CHSiMe₃)(CH₂SiMe₃), [F₃N₂NMe]Ta(η²-C₂H₄)(CH₂CH₃), and [Cl₂N₂NMe]TaMe_2..     

Synthesis, structure and properties of TTF-carboxylate bridged paddlewheel dirhodium complexes, Rh2(BuCO2)3(TTFCO2) and Rh2(BuCO2)2(TTFCO2)2

Reaction of tetrathiafulvalene carboxylic acid (TTFCO₂H) with paddlewheel dirhodium complex Rh₂(Bu^tCO₂)₄ yielded TTFCO₂-bridged complexes Rh₂(Bu^tCO₂)₃(TTFCO₂) (1) and cis- and trans-Rh₂(Bu^tCO₂)₂(TTFCO₂)₂ (cis- and trans-2). Their triethylamine adducts [1(NEt₃)₂] and cis-[2(NEt₃)₂] were purified and isolated with chromatographic separation, and characterized with single crystal X-ray analysis. Trans-[2(NEt₃)₂] is not completely separated from a mixture of cis- and trans-[2(NEt₃)₂], but its single crystals were obtained from a solution of the mixture. A three-step quasi-reversible oxidation process was observed for 1 in MeCN. The first two steps correspond to the oxidation of the TTFCO₂ moiety and the last one is the oxidation of the Rh₂ core. The oxidation of cis-2 is observed as a two-step process with very similar E_1/2 values to those of the first two processes for 1. Both 1⁺ and cis-2²⁺ in MeCN at room temperature show isotropic ESR spectra with a g value of 2.008 and a_H = 0.135 mT for two equivalent H atoms and a_H = 0.068 mT for one H atom. The redox and ESR data of cis-2 suggest that the intramolecular interaction between the TTF moieties is very small.     

没食子酸对水稻细菌性条斑病菌细胞结构的影响

没食子酸(gallic acid, GA)是一种植物酚类化合物,具有多种生物活性。前期实验发现,GA对水稻细菌性条斑病菌(Xanthomonas oryzae pv. oryzicola, Xoc)具有较强的抑制作用。为了解该物质对Xoc的细胞结构和细胞膜的影响,该研究用电子显微镜观察GA对Xoc的形态结构的影响,通过测定GA处理后的Xoc培养液的电导率、紫外吸收物含量(260 nm的吸光值)、乳酸脱氢酶的活性以及菌体的二乙酸荧光素(fluorescein diacetate, FDA)的强度等,探讨了GA对Xoc细胞膜的完整性和通透性的影响。结果表明:经浓度为200 μg·mL^-1的 GA处理后,Xoc的菌体形态结构发生改变,表面有明显的凹陷或不规则囊泡状突起,表明GA对Xoc细胞壁有损伤作用。200 μg·mL^-1的GA处理24 h后,病菌培养液的电导率为135.48 μS·cm^-1(对照处理为127.85 μS·cm^-1)。GA处理2 h后,Xoc细胞荧光强度下降58.10%,说明病菌细胞内电解质外渗和细胞溶质发生渗漏; 同时,乳酸脱氢酶的活性增加,表明菌体的细胞膜受到破坏。此外,GA处理24 h后,Xoc培养液在260 nm下的吸光值为1.004(对照处理为0.018),表明病菌细胞膜的完整性受到破坏。这表明GA不仅破坏Xoc的细胞膜通透性,而且还影响膜的完整性。