外源一氧化氮供体SNP对黑麦草种子萌发和幼苗生长的影响

采用水培试验,研究了不同浓度NO供体硝普钠(SNP)对黑麦草种子萌发和幼苗生长的影响。结果表明:50和100μmol.L-1SNP促进了黑麦草种子的发芽率、幼苗干物质积累速率、萌发种子α-淀粉酶活性、幼苗叶片可溶性蛋白质及叶绿素含量的提高。根和叶片中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性及还原型谷胱甘肽(GSH)、抗坏血酸(ASC)含量增加,超氧阴离子(O.2-)积累速率和过氧化氢(H2O2)含量下降,丙二醛(MDA)积累降低。高浓度SNP(500~2000μmol.L-1)抑制种子的萌发和幼苗生长,幼苗叶绿素、可溶性蛋白质及GSH、ASC含量下降,MDA含量和H2O2、O.2-产生速率提高,SOD、POD和APX活性降低,但叶片CAT活性升高。推测NO可能通过提高种子淀粉酶活性和幼苗活性氧清除能力,促进黑麦草种子的萌发和幼苗生长。     

低温胁迫对巨尾桉幼苗膜脂过氧化及保护酶的影响

以木本植物巨尾桉幼苗为材料 ,研究低温胁迫对巨尾桉膜脂过氧化及保护酶的影响 ,测定了幼苗叶片的O 2(超氧阴离子 )产生速率、H2 O2 、(过氧化氢 )、MDA(丙二醛 )含量、相对电导率和SOD(超氧化物歧化酶 )、POD(过氧化物酶 )、CAT(过氧化氢酶 )、APX(抗坏血酸过氧化物酶 )活性。结果表明 :低温胁迫使叶片O 2 产生速率、H2 O2 、MDA含量和相对电导率增加 ,但抗寒锻炼植株的增幅远小于对照 ;抗寒锻炼植株的SOD、POD、CAT和APX活性均低于对照。     

钙对根际低氧胁迫下黄瓜幼苗活性氧代谢的影响

采用营养液栽培系统,以黄瓜品种中农8号为材料,研究了Ca2 对根际低氧胁迫下黄瓜幼苗体内超氧阴离子(O2?-)、过氧化氢(H2O2)、丙二醛(MDA)含量和超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、谷胱苷肽还原酶(GR)活性的影响.结果表明:低氧胁迫下黄瓜体内活性氧含量和保护酶活性均高于对照;低氧缺钙处理的活性氧含量最高,而保护酶活性却较低;营养液Ca2 浓度提高到8mmol/L后,显著降低了低氧胁迫下黄瓜幼苗体内MDA、H2O2含量和O?2-产生速率,提高了SOD、POD、CAT、APX、GR活性,说明Ca2 可减少低氧胁迫下黄瓜幼苗体内活性氧的产生,提高抗氧化酶的活性、降低膜脂过氧化水平,减缓低氧胁迫对植株的伤害,增强黄瓜幼苗对低氧逆境的适应性.     

根系渗透胁迫时杨树光合作用光抑制与活性氧的关系

为更多地了解自然条件下活体叶片的光抑制,研究了渗透胁迫时杨树无性系幼苗叶片的光抑制与活性氧代谢的关系．结果表明,随胁迫时间的延长和胁迫强度的增大,杨树叶片O2^-生成加快,H2O2和丙二醛(MDA)含量增多,超氧物歧化酶(SOD)活性升高,过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性降低,活性氧代谢失衡,光合作用的光抑制加剧．用二乙基二硫代氨基甲酸铜盐抑制SOD活性,或用甲基紫精加速O2^-的生成,亦可使杨树叶片发生光抑制．渗透胁迫时杨树无性系幼苗清除H2O2能力降低,限制了叶片通过Mehler反应耗散过剩光能,防御光破坏作用的发挥;光抑制的发生与活性氧的积累有关．     

化学杂交剂诱导的小麦生理型雄性不育花药的活性氧代谢

以化学杂交剂SQ-1诱导的生理型小麦雄性不育及其对照植株花药为材料,研究了不同花粉发育时期花药中超氧阴离子(O-·2)生成速率、过氧化氢(H2O2)和丙二醛(MDA)含量以及主要抗氧化酶活性的变化,以探明小麦花药活性氧代谢和生理型雄性不育的关系.结果表明,在幼穗时期,O-·2生成速率、H2O2和MDA含量、超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性均高于相应对照,而过氧化物酶(POD)和过氧化氢酶(CAT)活性则低于或显著低于对照;在单核早期以及花粉败育主要发生期(单核后期和二核初期),O-·2生成速率、H2O2和MDA含量极显著高于对照,而SOD、POD、CAT和APX酶活性却极显著低于对照;在败育后的花药中,O-·2生成速率和H2O2含量与对照之间差异幅度缩小,但MDA含量依然加大,同期的几种抗氧化酶活性依然极显著低于对照.在败育的关键期,品种'西农1376'处理株花药的活性氧升高幅度比'西农2611'处理株较大,抗氧化酶活性降低幅度也较大,且'西农1376'处理株的相对雄性不育率也较高.可见,化学杂交剂SQ-1能诱导小麦花药中O-·2和H2O2大量积累以及SOD、POD、CAT和APX活性的极显著降低,引起花粉关键败育期花药活性氧代谢严重失衡和严重膜脂过氧化,导致大量花粉母细胞发育受到严重抑制,最终造成小麦生理型雄性不育.     

1,2,4-三氯苯胁迫对萌发大豆种子中活性氧的影响

以盆栽法研究了不同浓度 1,2 ,4 三氯苯 (TCB)胁迫对萌发大豆种子中活性氧代谢的影响 .结果表明 ,10 0～ 30 0 μg·g-1TCB胁迫初期 (1～ 3天 )促使萌发大豆种子呼吸强度升高及其峰值提前出现 ,超氧阴离子自由基 (O2 - )及过氧化氢 (H2 O2 )的积累显著增加 ,同时伴随丙二醛 (MDA)含量升高 ,显示发生膜脂质过氧化作用 .TCB胁迫 1～ 6天使活性氧清除酶功能紊乱 ,其中过氧化物酶 (POD)活性升高 ,超氧化物岐化酶 (SOD)活性开始上升后转为下降 .在萌发大豆种子受TCB胁迫伤害过程中 ,活性氧代谢失衡造成的膜脂质过氧化将起着重要作用 .     

硅和白粉菌诱导接种对黄瓜幼苗白粉病抗性影响的研究

研究了硅酸盐和诱导接种白粉菌对黄瓜活性氧代谢、SiO2含量和抗病性的影响．结果表明,诱导接种能使叶片的超氧自由基(O2^-)产生速率、H2O2和丙二醛(MDA)含量升高,加硅接种处理的O2^-产生速率、H202和MDA含量明显低于不加硅接种处理．诱导接种能使叶片的过氧化氢酶(CAT)、过氧化物酶(POD)活性升高,超氧化物歧化酶(SOD)活性降低．加硅接种处理植株叶片的CAT、POD和SOD活性明显高于不加硅接种处理．诱导接种提高叶片的抗坏血酸(AsA)和还原型谷胱甘肽(GSH)含量,加硅处理的AsA含量明显低于不加硅处理,GSH含量高于不加硅处理．无论接种与否,加硅处理的SiO2含量显著高于不加硅处理,病情指数明显低于不加硅处理．     

渗透胁迫下钙对巨尾桉苗木生长和保护酶及膜脂过氧化的影响

控制培养液中钙含量(0、5、10、15mmol/L)研究水分胁迫(-0.8Mpa)下,钙对巨尾桉苗木生长及叶片中超氧阴离子(O2-.)产生速率、过氧化氢(H2O2)和丙二醛(MDA)含量、相对电导率和超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性的影响。结果表明:水分胁迫下,10mmol/L钙处理的苗木生长状况明显高于其它处理,与缺钙处理相比高生长增加35.3%,基径生长增加39.8%,生物总量增加28.1%,根/冠比增加29.8%;而O2-.产生速率、H2O2和MDA含量、相对电导率明显低于缺钙处理,SOD和CAT活性明显增高,而POD和APX活性明显降低。     

6-苄（基）腺嘌呤和抗坏血酸对渗透胁迫时杨树光合作用光抑制的影响

研究了6-BA和A5A对渗透胁迫时杨树幼苗叶片光合作用光抑制和活性氧代谢的影响．结果表明,渗透胁迫时杨树叶片净光合速率(Pn)和表观量子效率(AQY)降低,光合作用光抑制加剧,超氧化物歧化酶(SOD)活性升高,抗坏血酸过氧化物酶(APX)活性降低,O2产生加快,H2O2和膜脂过氧化产物丙二醛(MDA)含量升高．6-BA和A5A预处理使胁迫时叶片SOD和APx活性升高。O2生成减少。H2O22和MDA含量降低,同时缓解了光合作用的光抑制．相关分析表明,杨树叶片活性氧水平和MDA含量与Pn和AQY呈负相关．胁迫时杨树叶片活性氧的积累与光合作用光抑制有一定关系,6-BA和A5A对光抑制的缓解作用与其对活性氧清除系统的促进作用有关。     

钙抑制剂对机械损伤胁迫下合作杨叶片活性氧代谢的影响

以1年生合作杨扦插苗为材料,研究了叶面喷施Ca2+通道阻断剂氯化镧(LaCl3)和Ca2+螯合剂EGTA预处理对机械损伤胁迫下合作杨叶片抗氧化酶活性、过氧化氢(H2O2)和丙二醛(MDA)含量以及氧自由基(O2?-)产生速率的影响.结果显示,与对照相比,机械损伤胁迫下合作杨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)等抗氧化酶活性均显著升高,活性氧水平和MDA含量显著增加;外源喷施EGTA和LaCl3降低了机械损伤胁迫下叶片SOD、POD、CAT和APX活性,减缓了O2?-产生速率,H2O2含量和MDA含量显著下降;且EGTA的抑制作用比LaCl3更强.研究表明,机械损伤胁迫诱导的活性氧代谢需要Ca2+的参与,Ca2+和活性氧在植物防御信号传递过程中密切相关;伤害诱导胞外Ca2+内流是胞内Ca2+浓度增加的重要来源.     

野牛草克隆分株酶促活性氧清除系统对差异光周期的响应

以盆栽野牛草克隆分株为材料,将克隆分株分别标记为O(姊株)和Y(妹株),设置连接组和断开组两种处理,其中,连接组中O分株和Y分株通过节间子相连,断开组则剪断分株节间子;两组处理的O分株光周期均设置为光照12h/黑暗12h,Y分株光周期均设置为黑暗12h/12h光照(恰好与O分株相反),经过7d的差异光周期处理后进行72h全光照稳定培养,并于全光照条件下在48h内连续测定各分株叶片超氧化物歧化酶(SOD),过氧化物酶(POD),过氧化氢酶(CAT),抗坏血酸过氧化物酶(APX)的活性以及丙二醛(MDA)的含量,探讨野牛草叶片酶促活性氧清除系统对差异光周期的响应特征。结果表明,差异光周期处理1周后,全光照条件下,断开状态的野牛草克隆分株O和Y间叶片中SOD、POD、CAT、APX活性以及MDA含量在24h内基本呈现相反的变化趋势,而野牛草相连克隆分株O和Y间叶片中以上指标在24h内呈现趋于一致的变化规律。研究发现,野牛草酶促活性氧清除系统活性在一天内呈现节律性表达模式,且差异光周期处理下的野牛草相连克隆分株的活性氧清除系统的活性的节律性变化趋于同步。     

夜间低温胁迫对番茄叶片活性氧代谢及AsA-GSH循环的影响

以番茄品种‘辽园多丽’为试材,利用人工气候室模拟设施生产中的夜间低温胁迫环境,研究9℃和6℃夜低温对番茄叶片活性氧代谢和AsA-GSH循环的影响。结果显示:9℃和6℃夜间低温胁迫3～9d可诱导番茄叶片中超氧阴离子(O2.-)产生速率、过氧化氢(H2O2)和丙二醛(MDA)含量上升;抑制过氧化物酶(POD)、过氧化氢酶(CAT)的活性,增加超氧化物歧化酶(SOD)和AsA-GSH循环中抗坏血酸过氧化物酶(APX)、脱氢抗坏血酸还原酶(DHAR)、谷胱甘肽还原酶(GR)的活性,并提高还原型抗坏血酸(AsA)、还原型谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)的含量。研究表明,在夜间低温胁迫过程中,增加的番茄叶片中SOD活性和AsA-GSH循环清除活性氧的能力并未与氧还原的速率一致,从而导致番茄叶片中活性氧的累积,使细胞膜系统受到一定破坏,在6℃处理的植物中尤为明显。     

Changes in activities of antioxidant enzymes during <Emphasis Type="Italic">Chenopodium murale</Emphasis> seed germination

The activities and isoenzyme pattern of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) have been studied during germination of Chenopodium murale seeds. CAT and SOD activities were similar in dry seeds and during first 2 d of imbibition. CAT activity increased during radicle protrusion and early seedling development. The maximum SOD activity was found at final stages of germination and early seedling development. POD activity was not detected until the 6^th day of germination, indicating POD involvement not until early seedling development. Gibberellic acid (GA₃, 160 μM) delayed and synchronized C. murale germination.     

Aluminum-induced changes in reactive oxygen species accumulation, lipid peroxidation and antioxidant capacity in wheat root tips

The present study investigated the effects of aluminum on lipid peroxidation, accumulation of reactive oxygen species and antioxidative defense systems in root tips of wheat (Triticum aestivum L.) seedlings. Exposure to 30 μM Al increased contents of malondialdehyde, H₂O₂, suproxide radical and Evans blue uptake in both genotypes, with increases being greater in Al-sensitive genotype Yangmai-5 than in Al-tolerant genotype Jian-864. In addition, Al treatment increased the activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), glutathione reductase (GR) and glutathione peroxidase (GPX), as well as the contents of ascorbate (AsA) and glutathione (GSH) in both genotypes. The increased activities SOD and POD were greater in Yangmai-5 than in Jian-864, whereas the opposite was true for the activities of CAT, APX, MDHAR, GR and GPX and the contents of AsA and GSH. Consequently, the antioxidant capacity in terms of 2,2-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging activity and ferric reducing/antioxidant power (FRAP) was greater in Jian-864 than in Yangmai-5.     

Salinity up-regulates the antioxidative system in root mitochondria and peroxisomes of the wild salt-tolerant tomato species Lycopersicon pennellii

The effect of salinity on the antioxidative system of root mitochondria and peroxisomes of a cultivated tomato Lycopersicon esculentum (Lem) and its wild salt-tolerant related species L. pennellii (Lpa) was studied. Salt stress induced oxidative stress in Lem mitochondria, as indicated by the increased levels of lipid peroxidation and H(2)O(2). These changes were associated with decreased activities of superoxide dismutase (SOD) and guaiacol peroxidases (POD) and contents of ascorbate (ASC) and glutathione (GSH). By contrast, in mitochondria of salt-treated Lpa plants both H(2)O(2) and lipid peroxidation levels decreased while the levels of ASC and GSH and activities of SOD, several isoforms of ascorbate peroxidase (APX), and POD increased. Similarly to mitochondria, peroxisomes isolated from roots of salt-treated Lpa plants exhibited also decreased levels of lipid peroxidation and H(2)O(2) and increased SOD, ascorbate peroxidase (APX), and catalase (CAT) activities. In spite of the fact that salt stress decreased activities of antioxidant enzymes in Lem peroxisome, oxidative stress was not evident in these organelles.     

Possible Involvement of Anti-Oxidant Enzymes in the Cross-Tolerance of the Germination/Growth of Wheat Seeds to Salinity and Heat Stress

The germination/growth of wheat （Triticum aestivum L. cv. Zimai 1） seeds and changes in the activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, and catalase （CAT）, as well as in the content of thiobarbituric acid-reactive substances （TBARS）, in response to salt and heat stress, as well as cross-stress, were investigated in the present study. With increasing temperature and decreasing water potential caused by NaCI solution, the germination percentage of seeds and the fresh weight of seedlings decreased markedly, SOD activity increased, activities of APX and CAT decreased distinctly, and the TBARS content increased gradually. Seeds pretreated at 33℃ for different times displayed increased tolerance to subsequent salt stress, enhanced SOD, APX, and CAT activities, and decreased TBARS content. Seeds pretreated at -0.8 MPa NaCI for different times displayed increased tolerance to subsequent heat stress and marked increases in SOD, APX, and CAT activities, which were associated with decreased TBARS content. It is considered that the common component in the cross-tolerance of the germination and growth of wheat seeds to salinity and heat stress is the anti-oxidant enzyme system.     

荞麦种子萌发期多种抗氧化酶活性的研究

通过研究荞麦种子萌发期(0～7 d)超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(ASP)四种抗氧化酶的酶活性变化,以及对自由基等的清除效果,分析荞麦种子内在抗氧化酶系统在萌发期对细胞膜结构的修复及保护作用。实验结果表明:荞麦种子在萌发期产生的活性氧、自由基等对四种抗氧化酶均有激活效应,其中超氧化物歧化酶(SOD)活性最先上升,其他三种酶随其后被激活,四种酶的氧化反应存在一定关联性和协同作用。苦荞的抗氧化酶活性高于甜荞。     

The activity of antioxidant enzymes in Arabidopsis thaliana exposed to colchicine and H2O2

Studies on the possible interference of colchicine and H2O2 with the activity of some antioxidant enzymes were carried out on Arabidopsis thaliana v. Columbia grown in Murashige and Skooge nutrient medium. Measurements of superoxide dismutase (SOD), guaiacol peroxidase (POX), ascorbate peroxidase (APX) and catalase (CAT) activities were conducted spectrophotometrically. In the presence of colchicine, SOD activity increased, while CAT, APX and POX activities decreased. Inhibitory H2O2 effects on the activity of the enzymes were found. Colchicine pre-treatment resulted in an increase in CAT activity and a further increase in SOD activity in plants treated with H2O2.