外源过氧化氢对烟草花芽分化的影响初探

通过盆栽试验,对外源H₂O₂处理的烟草活性氧代谢及烟草花芽分化情况进行了初步研究。结果表明：（1）外源H₂O₂处理显著影响了烟草体内活性氧代谢,H₂O₂和O₂ ^-含量迅速增加;保护酶POD和CAT活性迅速被激活,SOD的激活滞后于POD和CAT。喷施H₂O₂处理的中后期H₂O₂的含量下降。（2）外源H₂O₂胁迫改变了开花基因的表达、现蕾时烟草叶片数以及花芽的发育进程。5和15d的外源H₂O₂处理明显抑制了烟草FLC基因的表达,促进了LFY基因的表达,促使烟草花发育提前。试验结果表明烟草体内活性氧平衡状态的变化影响烟草的花发育进程。     

强耐冷性水稻新品系J07-23抗氧化系统对长期冷水胁迫的响应

为了阐明强耐冷性水稻对长期冷水胁迫抗性的生理基础, 以水稻新品系J07-23和冷敏感的栽培稻秀子糯为试验材料, 研究长期冷水胁迫(19℃)下参试材料在开花期剑叶活性氧代谢、抗氧化酶活性、抗氧化剂含量的变化以及成熟后的穗部性状。结果表明, 在长期冷水胁迫下, 秀子糯剑叶的O₂产生速率、H₂O₂含量和MDA含量显著增加, 抗氧化系统中SOD、CAT和GR活性显著升高; J07-23剑叶H₂O₂含量显著增加, 而O₂产生速率和MDA含量无显著变化。J07-23的抗氧化酶(SOD、CAT、POD、APX和GR)活性极显著升高, 抗氧化剂(AsA和GSH)含量及AsA/DHA值和GSH/GSSG值也显著增加。依据耐冷性评价标准, J07-23具有极强耐冷性, 冷水胁迫下高的抗氧化酶活性和抗氧化剂含量是其耐冷性的生理生化基础。     

外源褪黑素降低黄瓜体内霜霉威残留的生理生化分析

为探究褪黑素(melatonin,Mel)对黄瓜体内农药降解中的调控作用,以黄瓜‘Y3F604’为材料,以氨基甲酯类农药霜霉威(C₉H₂₀N₂O₂)为处理试剂,采用灌根的方法研究外源施用1 mmol/L Mel对黄瓜体内霜霉威残留的影响,同时探究O₂^-·、H₂O₂、MDA、GSH和GSSG含量以及抗氧化酶和解毒酶的变化情况。结果表明,外源1 mmol/L的Mel处理显著降低了霜霉威处理48 h后黄瓜体内的霜霉威残留量。在霜霉威胁迫下,黄瓜叶片中O₂^-·、H₂O₂和MDA的含量明显增加,而外源Mel处理能够有效抑制霜霉威胁迫下黄瓜体内的O₂^-·、H₂O₂和MDA积累。与对照相比,外源Mel处理显著提高了霜霉威胁迫下SOD、CAT、POD、APX、GPX等抗氧化物酶活性,进一步促进GSH含量和总谷胱甘肽含量的增加,提高GSH/GSSG、GST与GR解毒酶活性。因此,外源施用Mel可提高黄瓜在霜霉威胁迫下的抗氧化能力和解毒能力,从而加速黄瓜体内霜霉威的代谢,是促进蔬菜残留农药降解的新途径。     

NO对损伤诱导的豌豆幼苗叶片抗氧化系统的影响

为了明确损伤后豌豆幼苗叶片内NO产生的途径及NO对其诱导的抗氧化系统的作用,以豌豆幼苗为试材,研究损伤胁迫下其内源NO含量、NR和NOS活性的变化,以及只有NO供体SNP处理和NO清除剂PTIO、NOS抑制剂L-NAME、NR抑制剂NaN₃喷施后损伤处理过24 h 时对豌豆幼苗叶片内H₂O₂和O₂ ^-·含量变化及对抗氧化酶SOD、POD、CAT、APX等的活性影响。结果表明,损伤处理后0~60 h 内豌豆幼苗叶片内NO含量呈双峰曲线;其中损伤处理早期（第1 峰值）NO的主要来源是NOS酶促途径,而后期（第2 峰值）NO的主要来源是NR酶促途径;损伤处理24 h 豌豆幼苗叶片内NO含量最高,此时H₂O₂和O₂ ^-·含量接近对照水平,而SOD、POD、CAT、APX等的活性显著高于对照,NO供体SNP处理时有类似的结果,NO清除剂PTIO 处理后H₂O₂和O₂ ^-·含量升高,SOD、POD、CAT、APX等的活性降低。以上研究结果表明,NO可能通过增强保护酶的活性来降低损伤诱导的膜脂过氧化程度。     

葱细胞质雄性不育与花蕾发育过程中活性氧代谢关系研究

以葱细胞质雄性不育系CA及其同核异质保持系CB为材料,通过分析花蕾发育过程中活性氧(O2)产生速率、丙二醛(MDA)含量以及抗氧化酶(超氧化物歧化酶、过氧化氢酶、过氧化物酶)活性变化研究了活性氧产生与清除的动态变化.结果表明:不育系花蕾败育初期,活性氧产生速率持续增加至败育盛期达最高值,而丙二醛含量变化则从中蕾期开始大量积累至败育盛期接近最高值,表现一定的滞后性.两系比较,从小蕾期开始不育系活性氧产生速率和丙二醛含量显著高于保持系.受活性氧产生的诱导作用,败育始期超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性均呈增加趋势,但在败育盛期SOD、CAT活性明显下降,显著低于保持系.而POD活性则在中蕾期前低于保持系,之后显著高于保持系,造成雄性器官发育过程中IAA的亏缺.因此,葱花蕾发育过程中O2代谢失调和MDA过量积累以及保护酶活性下降或功能转变可能是导致雄性不育的重要因素.     

萝卜雄性不育系个体发育过程中3种同工酶活性的比较分析

以3种萝卜雄性不育系及保持系为试材,系统研究了它们在营养生长期及生殖生长期过氧化物酶(POD)同IM、酯酶(EST)同工酶及超氧化物歧化酶(SOD)同工酶活性的变化。结果表明：在营养生长期与生殖生长期的营养器官中,3种不育系的POD活性均低于保持系,而在生殖生长期的花蕾中,不育系的POD活性却高于保持系;EST活性变化表现出与POD相反的趋势;而作为清除氧自由基的SOD与败育关系不大。     

甘蓝型油菜雄性不育系09A花蕾发育过程中生理生化特性研究

通过分光光度法,对油菜细胞质雄性不育系09A和保持系09B不同发育时期花蕾中POD、CAT、SOD、APX的活性和MDA、游离Pro含量进行了测定,并讨论分析了与雄性不育之间的关系。结果表明：不育系09A不同发育阶段花蕾中CAT、SOD、APX三种酶活性均低于09B;POD活性在不育系花蕾发育早期低于09B,但随着花蕾的发育,09B的POD活性逐渐下降,而09A的POD活性则逐渐升高;不育系09A的MDA含量在整个花蕾发育过程中均高于09B,而Pro含量则低于09B。     

高温胁迫下NO对铁线莲光合特性和活性氧代谢的影响

一氧化氮(nitric oxide,NO)作为一种新的植物生长调节剂,对植物胁迫应答具有积极的作用。本研究以铁线莲‘钻石’品种幼苗为材料,对其施加不同浓度(0,0.1,0.4,0.8,1.2 mmol/L)的外源NO供体硝普钠(SNP)并进行高温胁迫处理,分析质膜透性、活性氧代谢、光合特性等变化。结果表明,高温胁迫下外源NO处理可以显著降低铁线莲幼苗叶片相对电导率和MDA含量(P<0.05),减少H₂O₂和O₂^-的积累;同时外源NO处理可以增强抗氧化酶(SOD,CAT,POD)的活性,提高F_v/F_m、ETR、Φ_PSⅡ、NPQ (P<0.05),维持较高的PSⅡ光化学活性,由此提高铁线莲耐高温能力,其中0.4 mmol/L NO处理效果最明显。上述结果表明,外源NO处理缓解高温对铁线莲的伤害可能与抗氧化酶活性和光合特性的提高有关。     

非1B/1R类型小麦雄性不育系KTSP3314A败育的生化机制

为了揭示K型非1B/1R类型小麦不育系雄性败育的生化机制。利用K型非1B/1R类型小麦雄性不育系KTSP3314A,其同型保持系TSP3314B,以K型1B/1R类型小麦雄性不育系K3314A、其同型保持系3314B为对照,分别对其叶片和穗子在不同发育时期的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)的活性和丙二醛(MDA)含量的变化进行测定。结果表明,K型非1B/1R类型小麦不育系中SOD,POD及CAT活性变化与K型1B/1R类型小麦雄性不育系酶活性变化一致,K型非1B/1R类型雄性不育小麦叶片和穗子的超氧化物歧化酶(SOD)后期则较低,过氧化氢酶(CAT)、过氧化物酶(POD)的活性后期较高,丙二醛(MDA)含量后期较高。说明二者的雄性败育生化机制基本一致,但前者比后者败育的时期较晚。且超氧化物歧化酶(SOD)活性与雄性育性有关。     

NaCl胁迫下西瓜种子对蛭石引发的响应

以西瓜品种“小皇冠”和“早佳8424”种子为试验材料，采用种子萌发袋发芽的方法，研究在不同浓度(0,50,75,100,125 mmol/L) NaCl溶液胁迫下，蛭石引发处理对西瓜种子发芽指标及幼苗生理特性的影响，探讨引发处理对缓解西瓜盐胁迫伤害的可行性。结果表明，随着NaCl浓度增加对西瓜种子萌发的抑制作用逐渐加剧，引发处理提高了NaCl胁迫下西瓜种子发芽势和发芽率；NaCl胁迫下，西瓜胚根超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性升高，过氧化氢(H₂O₂)、丙二醛(MDA)和可溶性糖含量增加；引发处理下胚根的SOD、POD、CAT活性增强，MDA和H₂O₂含量减少，可溶性糖含量增加。研究表明，引发处理能促进NaCl胁迫下西瓜种子萌发，促进可溶性糖的积累，诱导抗氧化酶活性，降低MDA和H₂O₂的积累，增强西瓜幼苗的耐盐性。     

CMS水稻不同器官的膜脂过氧化水平

比较了ＣＭＳ水稻不育系珍汕９７Ａ及其同核异质保持系珍汕９７Ｂ的叶片、幼穗和花药中的膜脂过氧化、活性氧水平及活性氧清除酶活性。结果表明：与可育花药相比，不育花药中Ｈ２Ｏ２和Ｏ２＾－水平较高，丙二醛（ＭＤＡ）含量也高，而超氧化物歧化酶（ＳＯＤ）、过氧化氢酶（ＣＡＴ）、过氧化酶（ＰＯＤ）和抗坏血酸过氧化物酶（ＡＳＡ－ＰＯＤ）活性则较低；幼穗中，不育系的Ｈ２Ｏ２和ＭＤＡ含量高于保持系，其它指标基本无差异；     

小麦质不育系及其保持系花药中SOD同工酶和脂质过氧化作用初步研究

对小麦Ｔ型和Ｐ型细胞质雄性不育系及保持系花药中ＳＯＤ活性、ＳＯＤ同工酶及脂质过氧化作用的研究结果表明，单核期不育系花药中的ＳＯＤ活性比保持系略低，ＳＯＤ同工酶带数与保持系相同。到二核期和三核期不育系花药中缺少一条ＳＯＤ同工酶带，ＳＯＤ活性也比保持系明显降低。不育系花药在三个发育时期的ＭＤＡ含量均明显高于保持系。同时发现在三核期不育系旗叶减少一条ＳＯＤ同工酶带。体内活性氧清除能力降低及脂质过氧化用加     

Response of the Flag Leaves of a Super‐Hybrid Rice Variety to Drought Stress during Grain Filling Period

The effect of drought stress on the antioxidant system and membrane lipid peroxidation in flag leaves of a super‐hybrid rice variety (Liang‐You‐Pei‐Jiu, LYPJ) during the grain filling period was studied. During prophase of water deficit up to day 6 at relative soil water content (RSWC) 88 %, 81 %, 69 %, the superoxide dismutase (SOD) activity descended slightly, but the activities of peroxidase (POD) and catalase (CAT) ascended rapidly. The content of ascorbic acid (AsA) and glutathione (GSH) decreased. The production rate of superoxide radical (O₂^?), the contents of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) were maintained in a low level (0.3481 nmolO₂^? mg^?1 protein min^?1, 170.17 μmol g^?1 FW, 1.467 nmol g^?1 FW, at day 6, respectively). The total membrane lipids and index of unsaturated fatty acids (IUFA) did not change obviously. Thereafter (day 9, 12, with 52 %, 28 %, respectively RSWC), the activities of these enzymes declined significantly, while the content of AsA + GSH showed a reverse tendency. However, O₂^? production rate, the contents of H₂O₂ + MDA also increased rapidly. As a result, the total membrane lipids and IUFA dramatically decreased. The results indicated that the whole protect system was destructed seriously; any single protective component could not resist the damage caused by drought stress.     

Deastringency treatment with CO2 induces oxidative stress in persimmon fruit

Because of astringency at harvest, ‘Rojo Brillante’ persimmons are regularly submitted to deastringency treatment based on exposing fruit to a high CO₂ concentration. The treatment conditions that ensure total astringency removal throughout the various maturity stages have been determined to be 95% CO₂, 20 °C, 24 h. The aim of this study was to investigate changes in the redox state of persimmon fruit associated with this deastringency treatment. The levels of reactive oxygen species (ROS) (O₂⁻ and H₂O₂), and the activities of the main ROS scavenging enzymes (CAT, POD, APX, and SOD), were determined at harvest and after deastringency in fruit at three different maturity stages.Our results showed that during ‘Rojo Brillante’ persimmon maturation, the level of O₂⁻ gradually increased, while APX activity was lowered. The deastringency treatment with CO₂ induced oxidative stress in the fruit, observed as an over-accumulation of O₂⁻ and H₂O₂. As a response to ROS accumulation, the activities of the CAT, APX and SOD scavenging enzymes were up-regulated after deastringency treatment. The response of POD enzyme was dependent on maturity stage, showing enhanced activity after CO₂ treatment only for the fruit at the most mature stage.     

多胺氧化酶(PAO)调控光诱导玉米中胚轴伸长的生理机制

以长中胚轴玉米自交系PH4CV为材料,在黑暗和光照两种处理条件下研究了玉米中胚轴长度与多胺氧化酶(Polyamine Oxidase, PAO)活性、H₂O₂含量、过氧化物酶(peroxidase, POD)活性及木质素含量的关系。通过添加5 mmolL^-1 PAO抑制剂2-羟乙基肼(2-hydroxyethylhydrazine, 2-HEH)和5 mmolL^-1 H₂O₂清除剂N,N’-二甲基硫脲(N,N’-Dimethylthiourea, DMTU)及组织化学染色,研究了影响中胚轴伸长的H₂O₂来源及其积累部位。采用实时荧光定量PCR(qRT-PCR)方法,探究了光对ZmPAO基因表达的影响。结果表明,光照处理显著抑制了玉米中胚轴的伸长,同时显著增加该部位的PAO活性、H₂O₂含量、POD活性及木质素含量。相关性分析表明,玉米中胚轴长度与PAO活性、H₂O₂含量和木质素含量呈极显著负相关,与POD活性呈显著负相关;PAO活性与H₂O₂含量、POD活性和木质素含量均呈正相关。外源PAO抑制剂和H₂O₂清除剂处理试验,玉米中胚轴表皮纵切面细胞长度显微观察及中胚轴H₂O₂组织化学染色表明,PAO氧化分解多胺(Polyamines, PAs)产生的H₂O₂参与了中胚轴细胞伸长的生理调控,从而抑制了中胚轴的伸长。表达分析表明,ZmPAO基因在黑暗环境下的表达量相对稳定,光刺激0.5 h后表达量迅速升高,3 h后达到最大值,随后逐渐下降,10 h后趋于稳定。本研究表明,PAO在接受光刺激后活性升高,氧化分解PAs产生H₂O₂,从而诱导POD氧化胞壁的单木质醇并聚合为木质素,使细胞壁硬化,造成细胞伸长受阻。研究结果为进一步探讨PAO活性调控光诱导玉米中胚轴伸长的生理机制和阐明玉米中胚轴对光逆境的响应机理提供了理论依据。     

甜菜胞质雄性不育系与保持系某些生理特性的差异

采用比较生理学的方法，对甜菜细胞质雄性不育系及其保持系生殖生长阶段的某些生理特性进行了研究。结果表明，甜菜细胞质雄性不育系的细胞色素氧化酶及ATP酶活性均表现为不育系低于其保持系；过氧化物酶和过氧化氢酶活性则表现为不育系高于其保持系，这反映线粒体内外末端氧化酶活性的高低可能与胞质雄性不育有一定关系；赤霉素含量表现为胞质雄性不育系低于其保持系。     

The role of active oxygen metabolism in hydrogen peroxide-induced pericarp browning of harvested longan fruit

Effects of hydrogen peroxide (H₂O₂), as exogenous reactive oxygen, on browning and active oxygen metabolism in pericarp of harvested ‘Fuyan’ longan fruit were investigated. The results showed that as compared with the control fruit, there was a higher browning index in pericarp of H₂O₂-treated fruit. The fruit treated with H₂O₂ resulted in increased rate of superoxide anion (O₂⁻) production, reduced activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), decreased amounts of ascorbic acid (AsA), glutathione (GSH) and carotenoid, and increased malondialdehyde (MDA) content. These results indicated that H₂O₂-induced browning in pericarp of harvested longan fruit might be due to a reducing capacity of active oxygen scavenging and an increase of accumulation of O₂⁻, which might stimulate membrane lipid peroxidation, disrupt cellular membrane structure, and cause the loss of cellular compartmentalization, in turn, resulting in the contact of polyphenol oxidase (PPO) and peroxidase (POD) with phenolic substrates and subsequently oxidation phenolics to form brown polymers.     

水稻叶片淀粉积累及早衰突变体esl9的鉴定与基因定位

利用EMS诱变籼型三系保持系西农1B,获得了一个新的水稻叶片淀粉过度积累而导致的早衰突变体esl9(early senescence leaf 9)。该突变体苗期叶片呈淡绿色,分蘖期开始除心叶外的叶片从叶尖开始黄化衰老,逐渐延伸至叶中上部,基部保持绿色,该性状一直持续到成熟。与野生型相比,esl9叶片光合色素含量下降,O_2~-、·OH和H_2O_2等活性氧含量上升,保护酶系统中SOD和CAT活性降低。组织化学分析表明,esl9叶片中积累了大量的淀粉颗粒,淀粉含量显著上升;qRT-PCR结果显示,淀粉合成途径相关基因上调,磷酸丙糖(TP)分配途径基因下调,推测基因突变可能改变了TP的分配途径,导致叶片过度积累淀粉,破坏叶绿体结构,光合系统受阻,活性氧增多,引起叶片黄化衰老。遗传分析表明该突变体受一对显性核基因调控,ESL9位于第11染色体标记S11-110与S11-87之间,物理距离为304.9 kb,这为进一步基因克隆和功能研究奠定了基础。     

玉米及高粱花药中三磷酸腺苷(ATP)含量与细胞质雄性不育的关系

本文采用发光分光光度计测定玉米和高粱的保持系和不育系花药中 ATP的含量,并与花药活力进行了比较,结果为:(1)玉米和高粱保持系花药中ATP 的含量均高于不育系,尤以高粱最为明显,高7倍。(2)凡 ATP 含量高的花粉均具有活力,ATP 含量高的活力高,而 ATP 含量低的活力亦低。(3)ATP 含量高的可育花粉萌发快,花粉管迅速伸长,ATP 含量低的不育系花粉在同样的条件下不萌发。     

Growth and Anti-Oxidative Systems Changes in Elymus dahuricus is Affected by Neotyphodium Endophyte Under Contrasting Water Availability

Although the relationship between fungal endophyte and agronomic grass (Lolium perenne and Festuca arundinacea) in drought tolerance are well documented, the mechanisms responsible for wild grass are not well understood. In this study, we determined the biomass production and growth parameters endophyte infected (E+) and endophyte uninfected (E−) Elymus dahuricus plants under high water (HW) and low water (LW) treatment for 8 weeks in a controlled‐environment condition experiment. We also determined the changes in the activities of the anti‐oxidative enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX) and content of H₂O₂, as well as levels of proline and chlorophyll a + b were examined in the leaves of E+ and E− plants. Under low water treatment, E+ plants produced more biomass and had higher values in plant height and tiller numbers, but no influence by the fungus were observed in high water treatment. Anti‐oxidative enzyme (include SOD, POD, CAT and APX) activities and contents of proline and chlorophyll a + b increased and H₂O₂ concentration declined in the E+ plants compared with E− plants under low water treatment. Therefore, endophyte infection was a benefit to growth and anti‐oxidative affection E. dahuricus under low water treatment.