NaHCO3处理对西伯利亚蓼叶细胞膜脂过氧化和活性氧清除酶活性的影响

对西伯利亚蓼扦插苗进行不同浓度和不同时间NaHCO3处理,研究了NaHCO3处理浓度和时间对西伯利亚蓼叶细胞膜脂过氧化和活性氧清除酶活性的影响。研究表明,NaHCO3处理浓度分别与过氧化氢酶活性、丙二醛含量和细胞膜透性之间存在极显著正相关性,与超氧化物歧化酶活性之间存在显著正相关性,与过氧化物酶活性之间无显著相关性;不同NaHCO3浓度处理间,超氧化物歧化酶活性、过氧化氢酶活性及丙二醛含量差异极显著,过氧化物酶活性和细胞膜相对透性差异显著;不同时间的NaHCO3处理,过氧化物酶活性、过氧化氢酶活性、丙二醛含量及细胞膜透性差异显著,超氧化物歧化酶活性和过氧化氢酶活性差异极显著。     

贮藏时间对银杏花粉保护酶活性和萌发率的影响

研究了室温贮藏对银杏花粉萌发率及超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化物酶(Peroxi-dase,POD)、过氧化氢酶(Catalase,CAT)活性的影响。结果表明,随着贮藏时间的延长,花粉萌发率由88．89％降到15．76％;贮藏15d之后超氧化物歧化酶活性降低了80％;过氧化物酶活性减少到原来的10％;过氧化氢酶活性也减少了70％。在室温贮藏条件下萌发率随保护酶活性的下降而降低。POD酶对花粉萌发率的影响比SOD、CAT酶显著。     

贮藏方式对切花菊贮后品质的影响

研究了干、湿贮藏方式及其贮藏期对三种不同发育程度切花菊贮后品质的影响。两种湿藏能促进切花发育,贮藏6周后切花花径分别增大了2.54cm(清水)和3.29cm(S+AgNO_3),但不能延长贮藏期;干藏能延长贮藏期,可贮期达4～6周,提高切花催开后品质。     

千层塔生物学特性的初步研究

简要测定了千层塔植株的根系活力 ,过氧化物酶、过氧化氢酶、苯丙氨酸解氨酶活性 ,以及植物各部位的可溶性蛋白质、可溶性糖、脯氨酸、丙二醛含量 ,旨在从植物生理学角度对千层塔有一个基本的了解。     

萝卜贮藏期过氧化物酶活性及同工酶谱研究

为了研究萝卜贮藏期过氧化物酶的活性变化和作用 ,利用愈创木酚法和聚丙烯酰胺凝胶电泳方法检测在贮藏期萝卜过氧化物酶的活性及同工酶谱 ,实验结果表明 :不同品种的萝卜在不同贮藏时期其过氧化物酶活性及同工酶谱存在差异。贮藏时间越长过氧化物酶活性越高 ,同工酶谱酶带增多。萝卜色素含量越高 ,POD活性也越高 ,因此 ,在萝卜贮藏期有可能过氧化物酶在清除细胞内H2 O2 方面起主要作用     

NaHCO3处理对西伯利亚蓼叶细胞膜脂过氧化和活性氧清除酶活性的影响

对西伯利亚蓼扦插苗进行不同浓度和不同时间NaHCO₃处理,研究了NaHCO₃处理浓度和时间对西伯利亚蓼叶细胞膜脂过氧化和活性氧清除酶活性的影响。研究表明,NaHCO₃处理浓度分别与过氧化氢酶活性、丙二醛含量和细胞膜透性之间存在极显著正相关性,与超氧化物歧化酶活性之间存在显著正相关性,与过氧化物酶活性之间无显著相关性;不同NaHCO₃浓度处理间,超氧化物歧化酶活性、过氧化氢酶活性及丙二醛含量差异极显著,过氧化物酶活性和细胞膜相对透性差异显著;不同时间的NaHCO₃处理,过氧化物酶活性、过氧化氢酶活性、丙二醛含量及细胞膜透性差异显著,超氧化物歧化酶活性和过氧化氢酶活性差异极显著。     

热水处理对金柑果实采后腐烂及生理特性的影响

金柑是果皮和果肉同食的柑果类型,对采后处理要求极为严格。该研究以金柑(Fortunella crassifolia)为材料,研究了其经30、40和50℃热水浸泡后果实的腐烂率、失重率、可溶性固形物、硬度、有机酸、细胞渗透率以及抗氧化酶活性变化。结果表明:经30℃热水处理5 min的果实失重率高于对照,而经40℃和50℃处理的果实失重率低于对照或差异不显著。经热水处理的果实总酸含量略低于对照,可溶性固形物含量在18%上下波动且差异不显著。热水处理可提高果实硬度,降低贮藏前期果实细胞渗透率以及贮藏过程中果实过氧化物酶和超氧化物歧化酶活性,激发过氧化氢含量升高,可有效降低贮藏过程中金柑果实腐烂率,但不同采收期的金柑所需的热水处理温度和时间不同。对于1月初采收的果实,处理时间为5 min或10 min可降低果实腐烂率;2月初采收的果实,40℃或50℃热水处理10 min可有效降低果实腐烂率;3月初采收的果实,当处理温度达到50℃,处理时间达到10 min,才可有效降低果实腐烂率,且对果实品质没有明显的不利影响。     

水杨酸对枣树组织培养苗几种生理生化指标的影响

研究了不同浓度水杨酸(0mmol／L、1mmol／L、5mmol／L、10mmol／L)对枣树一年生组织培养苗叶片含水量、可溶性糖含量、可溶性蛋白含量及过氧化物酶活性的影响。结果表明,枣树组织培养苗叶面喷洒不同浓度水杨酸可提高其叶片含水量、可溶性糖含量、可溶性蛋白含量和过氧化物酶活性,其中以1mmol／L喷洒效果显著。     

郁金香衰老过程中几种保护酶活性的变化

两个郁金香品种在开花后随着可溶性蛋白含下降,细胞内超氧化物歧化酶、过氧化氢酶和过氧化物酶３种保护酶活性也随之下降,同时发生过氧化产物丙二醛的迅速累积;     

苹果树腐烂病菌不同致病力菌株对苹果的诱导效应

以‘富士’苹果叶片为材料, 采用刺伤接种法, 比较了苹果树腐烂病菌强致病菌LXS080601和弱致病菌LXS081501侵染对寄主体内丙二醛（MDA）含量、渗透调节物质及防御酶活性的影响。结果表明, 两菌株侵染后, 叶片MDA、蛋白质和可溶性糖含量均增加, 接种LXS080601叶片MDA含量快速上升, 最大增幅为141.15%, 而接种LXS081501叶片的MDA含量变化较小, 增幅仅为1.16%-16.24%, 但后者可溶性糖和蛋白质含量增幅分别高达158.12%和113.57%, 显著高于接种LXS080601的处理。同时, 两菌株均能诱导叶片内4种防御酶活性的升高, 但LXS081501诱导的苯丙氨酸解氨酶（PAL）、过氧化物酶（POD）、过氧化氢酶（CAT）和多酚氧化酶（PPO）活性均显著高于LXS080601, 说明不同致病力腐烂病菌对寄主防御酶活性的影响存在显著差异。     

保鲜剂对夏季香石竹切花衰老的延缓作用

香石竹切花瓶插期间花瓣中ＳＯＤ和蛋白质在前期上升,然后比处理组提前３天呈下降趋势。采后花瓣中ＣＡＴ、可溶性总糖和蔗糖均为下降。经由蔗糖、８－羟基喹啉和植物生长调节剂或钴镍盐组成的保鲜剂能延缓切花花瓣中ＳＯＤ、ＣＡＴ活性的下降,阻碍蛋白质、可溶性总糖和蔗糖的降解速度,同时使切花的瓶插寿命延长、含水量增加。     

采收期对‘红心’番石榴品质和耐贮性的影响

以福建漳州栽培的‘红心’番石榴(Psidium guajava ‘Hongxin’)为材料,探究不同采收期对其果实采后耐贮性和品质的影响。实验分盛花期后95 d (采收期Ⅰ)、105 d (采收期Ⅱ)和115 d (采收期Ⅲ) 3个时段进行采收,采后果实在常温(25±1℃) 和相对湿度85%条件下贮藏,贮藏期间测定番石榴果实商品率、失重率、呼吸强度、相对电导率、色调角、硬度、可溶性固形物、可滴定酸、维生素C和总糖含量变化。结果表明,‘红心’番石榴果实采后软化迅速,颜色由绿转黄较快;随着采后贮藏时间的延长,番石榴果实的商品率、硬度、色调角、可滴定酸、维生素C和总糖的含量降低,而果实失重率、细胞膜相对透性增加;采收期Ⅰ较采收期Ⅱ、Ⅲ的耐贮性强。因此,对于‘红心’番石榴果实,考虑贮运期长,适宜在采收期Ⅰ采收;其他两个采收期可在产地销售。     

Characterization of ethylene production in developing strawberry fruit

Ethylene production, ACC content, and ACC oxidase activity were determined in strawberry fruit harvested at different stages of development and in fruit harvested green and developed in vitro in solutions containing sucrose. In fruit harvested at progressive stages of development from green through full ripe, ethylene production and ACC oxidase activity decreased whereas ACC content increased between the white and pink stages. Fruit detached at the green stage and developed to full ripe by immersion of the cut pedicel in sucrose solutions exhibited an increase in ACC content, decreased ethylene production, and no change in ACC oxidase activity. Detached green fruit provided with sucrose containing 0.5 mM silver (STS) had elevated ethylene production and more ACC oxidase activity than did fruit incubated without the silver salt. Green fruit provided with sucrose containing 1 mM ACC showed markedly increased ACC content, ACC oxidase activity, and ethylene production. These increases were noted following 4 days incubation in ACC, and were more pronounced after 11 days, at which time fruit of all treatments had attained a full-ripe stage of development. Calyx tissue exhibited more ACC oxidase activity, less ACC content, and similar ethylene production compared with receptacle tissue. ACC synthase could not be detected in fruit harvested at different developmental stages or in fruit detached and developed in vitro.abbreviations ACC 1-aminocyclopropane-1-carboxylic acid - HQS 8-hydroxyquinoline hemisulfate - SAM S-adenosyl methionine - STS silver thiosulfate     

Morphogenesis of the membrane-bound electron-transport system in sporulating Bacillus megaterium KM.

The properties of electron transport systems present in soluble and particulate fractions of spores of Bacillus megaterium KM?HAVE BEEN COMPARED WIth those of similar fractions prepared from exponential-phase vegetative cells of this organism. The timing and localization of modifications of the electron transport system occurring during sporulation have been investigated by using a system for separating forespores from mother cells at all stages during development [8]. Spore membranes contained cytochromes a + a3, and o at lower concentrations than in vegetative membranes, and in addition cytochrome c, which was not found in exponential-phase vegetative membranes. An NADH oxidase activity of similar specific activity was found in both spore and vegetative membranes but DL-glycerol 3-phosphate and L-malate oxidase activities were found only in vegetative membranes. A soluble NADH oxidase of low specific activity was found in spores and vegetative cells which probably involves a flavoprotein reaction with oxygen because the activity was stimulated by FAD or FMN and difference spectra of concentrated soluble fractions showed spectra typical of a flavoprotein. Particulate NADH oxidase was sensitive to all classical inhibitors of electron transport tested whereas soluble NADH oxidase was insensitive to many of these inhibitors. Cytochrome c was formed between stage I and II of sporulation and this coincided with a five-fold increase in NADH-cytochrome c reductase activity. Forespore membranes had lower contents of cytochromes than sporangial cell membranes but similar levels of NADH and L-malate oxidases; DL-glycerol 3-phosphate oxidase activity could not be detected in either membranes by stage III of sporulation. This characterization of spore electron transport systems provides a basis for suggestions concerning initial metabolic events during spore germination and the effect of a number of germination inhibitors.     

Adenine type and diphenyl urea derived cytokinins improve the postharvest performance of <Emphasis Type="Italic">Iris germanica</Emphasis> L. cut scapes

An experiment was designed to evaluate the effect of various adenine derived cytokinins (kinetin and 6-benzylaminopurine) and diphenyl urea cytokinin (thidiazuron) on the postharvest performance of cut scapes of Iris germanica. Flower scapes were harvested with the oldest bud at ‘1 day before anthesis stage’, brought to laboratory under water, cut to a uniform length of 35 cm, divided into three sets viz., kinetin (KIN), 6-benzyl aminopurine (BAP) and thidiazuron (TDZ). Each set of scapes was treated with a particular cytokinin alone or in combination with 0.1 M sucrose. TDZ was effective than KIN and BAP in improving the postharvest life of the I. germanica scapes by 5.4 days as compared to the control (untreated scapes held in distilled water). This was because of the minimum percentage of bud abortion by TDZ application. Cytokinin application resulted in increased antioxidant activity, higher protein and phenolic content, besides a decrease in specific protease activity and α-amino acids in the tepal tissues. Application of TDZ resulted in the maximum increase in the superoxide dismutase, catalase and ascorbate peroxidase activity in the tepal tissues. The scapes treated with BAP and KIN maintained higher carbohydrate content in the tissue samples as compared to control and TDZ treated scapes. TDZ and BAP application resulted in increased membrane stability because of the decreased lipoxygenase activity which prevented membrane lipid peroxidation. Among the cytokinins tested, TDZ proved to be the promising cytokinin in improving the postharvest performance of beautiful flowers of I. germanica scapes.     

木醋液对鲜切麝香百合的保鲜效应

以木醋液为保鲜液,对鲜切麝香百合进行瓶插保鲜的结果表明：木醋液能增强麝香百合吸收保鲜液的能力,延长其盛花期和瓶插寿命,增强过氧化氢酶（CAT）活性,降低麝香百合瓶插期间的丙二醛（MDA）含量和过氧化物酶（POD）活性,延缓其衰老,其中以3．4g&#183;L^-1木醋液对鲜切百合的保鲜效应最好。     

PG与番茄果实成熟的关系

系统比较了转多聚半乳糖醛酸酶（PG）反义基因和对照番茄果实成熟过程中绿熟、转色、粉顶、粉红、全红5个时期的PG活性和与其相关的生理、生化组分的动态变化。实验表明,转基因果与对照果相比,PG活性始终处于较低水平,PG活性强烈被抑制是在全红期;果实的硬度、贮藏寿命指数都高于对照果;番茄红素合成积累进程被延缓;可溶性果胶含量、电解质外渗百分率均低于对照果。外源乙烯刺激引起对照果PG活性剧增,而转基因果表现钝化。讨论了PG活性与果实成熟、耐贮性及软化的关系,及对外源乙烯刺激的敏感性。首次明确提出PG活性在对照果中极大地表达,在转基因果中强烈被抑制是在全红期 ,而不是在整个成熟期;PG活性在果实软化中起直接和重要作用;PG活性的高低与番茄红素的合成与积累有关。     

冷藏唐菖蒲切花瓶插过程中水分平衡及若干生理指标的变化

测定唐菖蒲新鲜切花和冷藏切花瓶插过程中的水分平衡、鲜重与某些生理指标的变化。结果表明,瓶插过程中,冷藏切花吸水和失水初时受阻,鲜重增加值大大低于新鲜切花;与瓶插同期的新鲜切花相比,冷藏切花各部位小花花瓣和苞片可溶性蛋白质明显降低,丙二醛(MDA)含量明显较高,过氧化物酶(POD)活性和过氧化氢酶(CAT)活性均明显下降。对唐菖蒲切花冷藏后品质变劣的原因作了讨论。     

Some antioxidant and senescence parameters of broccoli as related to its developmental stages

In broccoli heads grown in spring and in autumn, and harvested at four various developmental stages antioxidant ability as well as certain indices of plant senescence were investigated. Development of broccoli heads was accompanied by losses of chlorophyll and ascorbic acid. At pre-florescence stage accumulation of soluble phenolics was observed. Activity of peroxidase in the initial stage of growth increased significantly and its high level was mantained during the whole growing period. The profound evolution of ethylene was manifested by plants of the pre-florescence stage. In broccoli grown in spring the higher contents of chlorophyll and phenolics in comparison with the autumn experiment were observed, as well as slightly higher activities of peroxidase and catalase. Total antioxidant activity was considerably higher in spring than in autumn.     

Response characteristics of Scirpus trioueter and its rhizosphere to pyrene contaminated soils at different growth stages

Scirpus triqueter (Triangular club-rush), a typical wetland species, is used to study the response characteristics to pyrene. A pot experiment was conducted to investigate the growth parameters (height, diameter, shoot number, total volume, underground biomass, above-ground biomass and total biomass), and enzymes (catalase and superoxide dismutase) of S. triqueter. The characteristics of soil enzymes (catalase and polyphenol oxidase) and microorganisms (bacteria and fungi) were also assessed after pyrene treatment. Elevated pyrene concentration (80 mgkg(-1)) in the soil reduced the shoot number and biomass significantly, especially at the early growth stage. In root tissue, the enzyme catalase was activated at 80 mgkg(-1) of pyrene. Compared to roots, shoots had higher enzyme activities. Catalase activities in the rhizosphere increased throughout the growth period of S. triqueter. Polyphenol oxidase activities in the rhizosphere were higher than those in the bulk soil and unplanted soil. The populations of bacteria (total bacteria, pyrene-tolerant bacteria, and actinomyces) and fungi decreased under the stress of high pyrene concentration, while that of pyrene-tolerant bacteria increased with the increasing pyrene concentration. The presence of pyrene did not benefit the growth of S. triqueter. S. triqueter and soil enzymes varied within the growth stages. The presence of S. triqueter could improve the activity of soil enzymes and facilitate the propagation of microorganisms which could help eliminate pyrene contamination.