NaCl胁迫对茄子嫁接苗根系多胺代谢的影响

采用高压液相色谱法对80 mmol.L-1NaCl胁迫下营养液栽培茄子嫁接苗和自根苗根系多胺代谢的差异进行了研究。结果表明,胁迫2 d时,嫁接苗根系游离态亚精胺和结合态多胺含量显著高于自根苗,游离态腐胺和束缚态多胺显著低于自根苗,游离态精胺含量两者无显著差异。胁迫10 d时,自根苗3种形态的多胺含量均下降,显著低于对照植株,而嫁接苗根系游离态精胺、结合态腐胺和束缚态多胺含量显著高于对照植株。研究结果表明,NaCl胁迫显著提高了茄子嫁接苗和自根苗根系多胺氧化酶的活性,且自根苗增加幅度显著高于嫁接苗;嫁接苗胁迫初期根系结合态多胺的迅速积累及胁迫后期保持较高的精胺含量有利于其耐盐性的提高。     

嫁接对铜胁迫下黄瓜幼苗根系多胺代谢的影响

采用营养液栽培法,研究了嫁接(以黑籽南瓜为砧木)对铜胁迫下黄瓜幼苗根系活力及多胺代谢的影响.结果表明:铜胁迫下黄瓜幼苗根系活力下降,电解质渗漏率升高,而嫁接苗的变化幅度显著小于黄瓜自根苗;铜胁迫下黄瓜嫁接植株根系中除游离态腐胺(Put)含量显著低于自根苗外,结合态和束缚态Put、3种形态亚精胺(Spd)和精胺(Spm)含量均显著高于自根苗,嫁接苗根系中游离态Put含量及腐胺/多胺(Put/PAs)显著低于自根苗;铜胁迫下,嫁接苗根系精氨酸脱羧酶(ADC)、鸟氨酸脱羧酶(ODC)和S-腺苷蛋氨酸脱羧酶(SAMDC)活性高于自根苗,而二胺氧化酶(DAO)和多胺氧化酶(PAO)活性显著低于自根苗.表明嫁接黄瓜幼苗根系PAs的合成增加,降解减少,使PAs含量维持在较高水平,从而提高了黄瓜幼苗抗铜胁迫能力.     

嫁接茄子对NaCl胁迫的反应

NaCl处理自根茄子苗的半致死浓度为6.267 g·L-1.嫁接苗株高抑制率和茎粗抑制率均低于自根苗,自根苗受NaCl伤害明显重于嫁接苗.在NaCl胁迫下,嫁接苗的电导率和丙二醛(MDA)含量均低于自根苗,但其脯氨酸含量则明显高于自根苗.     

NaCl胁迫对茄子嫁接幼苗叶片抗坏血酸和谷胱甘肽代谢的影响

以Torvum Vigor为砧木,栽培品种苏崎茄为接穗,研究NaCl胁迫对茄子嫁接苗和自根苗抗氧化物质含量和H2O2产生及清除酶活性的影响.结果表明;(1)NaCl胁迫可诱导叶片中H2O2的产生,导致膜脂过氧化产物丙二醛(MDA)的积累,嫁接苗叶片中H2O2和MDA的含量显著低于自根苗.(2)在NaCl胁迫下,嫁接苗叶片中谷胱甘肽还原酶(GR)和抗坏血酸过氧化物酶(APX)活性上升,自根苗则下降;NaCl胁迫促进了嫁接苗还原型抗坏血酸(AsA)和还原型谷胱甘肽(GSH)的合成,嫁接苗叶片中AsA和GSH的含量显著高于自根苗.由此认为,茄子嫁接苗耐盐性优于自根苗的原因之一在于嫁接苗保持较快的AsA-GSH循环,从而保证GSH和AsA的再生以减轻氧化损伤.     

NaCl胁迫对茄子嫁接苗生长和离子分布的影响

以引进日本的设施栽培专用耐盐茄子品种Torvum Vigor为砧木,栽培品种苏崎茄为接穗,通过营养液栽培对80 mmol·L-1NaCl胁迫下茄子嫁接苗和自根苗的生长和离子分布进行了比较.结果表明,(1)NaCl胁迫下嫁接苗茎伸长受抑制程度显著低于自根苗,嫁接苗根部生长旺盛;(2)嫁接苗根部贮存一定量的Na 、Cl-,地上部除叶柄外各部位Na 、Cl-含量均显著低于自根苗;(3)NaCl胁迫后嫁接苗在幼叶和根部保持较高K /Na 和Ca2 /Na 值;(4)嫁接苗根部选择吸收SK,Na、SCa,Na值和幼叶选择运输SK,Na、SCa,Na值均显著高于自根苗.因此,嫁接茄子因根部Na 、Cl-的贮存,减轻了地上部的盐离子毒害,而且K 和Ca2 在幼叶和根部的特异积累使其K /Na 值和Ca2 /Na 值提高,从而增强了耐盐性.     

聚乙二醇胁迫下的番茄幼苗内ABA、JA和多胺含量以及多胺氧化酶活性的变化

聚乙二醇模拟的干旱胁迫下,2个品种番茄幼苗根和叶中脱落酸(ABA)和茉莉酸(JA)含量均迅速积累,叶中ABA累积比根中滞后;游离态亚精胺(fSpd)、精胺(fspm)、腐胺(fPut)含量和多胺氧化酶(PAO)活性均先上升,12 h时达到峰值后下降,耐旱性强的品种'毛粉802'幼苗根和叶中积累ABA、JA和spd、Spm的能力明显强于耐旱性弱的品种'皇冠'.'皇冠'的PAO活性提高程度大于'毛粉802'.番茄根和叶中多胺含量和PAO活性呈显著正相关.内源多胺的积累诱导ABA和JA含量的升高,从而导致番茄幼苗的耐旱性增强.     

NaCl胁迫对玉米和演藜时片中内源多胺含量与幼苗生长的影响(简报)

ＮａＣｌ胁迫下玉米内源腐胺和钠含量明显增加，亚精胺、精胺和钾含量显著降低，生长受到抑制。高浓度ＮａＣｌ胁迫下，滨藜内源多胺、销和钾含量变化情况与 ＮａＣｌ胁迫下的玉米有相同趋势。     

NaCl胁迫对菜用大豆种子游离态多胺含量的影响

采用蛭石栽培,在100 mmol·L-1 NaCl胁迫下,对耐盐性不同的2个菜用大豆[Glycine max (L.) Merr.]栽培品种的种子膨大及其游离态多胺(PAs)含量的变化进行了研究.结果显示:(1)耐盐品种'绿领特早'的荚重、种子大小及重量的增加在NaCl胁迫15 d时未受显著影响,而盐敏感品种'理想高产95-1'种子的膨大却受到了显著抑制.(2)'绿领特早'种子的腐胺(Put)含量在盐胁迫6～15 d时均显著低于对照,'理想高产95-1'在胁迫后期(12 d、15 d)才显著低于对照,且降幅低于同期的'绿领特早';'绿领特早'种子的亚精胺(Spd)含量在胁迫中、后期(9～15 d)显著高于对照,'理想高产95-1'在胁迫12 d时无显著变化,其余时期均显著低于对照;NaCl胁迫期间,'绿领特早'种子精胺(Spm)含量的增幅高于同期的'理想高产95-1'.(3)与'理想高产95-1'相比,'绿领特早'在胁迫期间能维持较低的Put/PAs值和较高的(Spd+Spm)/Put值.研究结果表明,耐盐菜用大豆'绿领特早'种子在NaCl胁迫期间能保持较高的Spm含量,并在胁迫中、后期保持较高的Spd含量,同时具有较强的Put向Spd和Spm的转化能力,这可能是其耐盐性较强的重要原因之一.     

NaCl胁迫对番茄嫁接苗生物量及离子含量的影响

以影武者为砧木,宝大903为接穗,研究了NaCl胁迫下番茄嫁接苗与接穗自根苗在生物量及Na 、K 、Ca2 、Mg2 、Cl-等含量方面的差异.结果显示,NaCl胁迫下,嫁接苗生长受抑制程度较轻;嫁接苗和自根苗Na 、Cl-含量增长幅度最大的部位均是叶片,嫁接苗增长幅度小于自根苗;K 、Ca2 、Mg2 含量下降幅度最大的部位均是根系,嫁接苗下降幅度小于自根苗;嫁接苗的K /Na 值、Ca2 /Na 值显著高于自根苗,说明嫁接苗选择性吸收K 、Ca2 能力显著强于自根苗.结果表明,NaCl胁迫下嫁接苗体内离子分布的区域化优于自根苗,耐盐性强于自根苗.     

外源钙和亚精胺对NaCl胁迫条件下玉米幼苗体内离子平衡和多胺水平的调节

研究了钙离子和亚精胺对盐胁迫条件下玉米幼苗生长状况、电解质渗漏、离子含量和多胺水平的影响。结果表明盐胁迫下,钠离子和腐胺含量升高,质膜受到严重伤害,而钾离子、钙离子、亚精胺以及精胺水平降低。外加氯化钙和亚精胺不但能逆转氯化钠带来的离子平衡失调、多胺代谢紊乱,而且还能减轻氯化钠导致的生长抑制和质膜伤害。在盐胁迫条件下,二环己基胺引起多胺含量严重下降的情况在一定程度上能被外加氯化钙处理所缓解。这些结果提示,钙、多胺代谢以及盐渍环境下玉米生长之间可能存在一定的关系。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.