镉和苯并[a]芘胁迫对小麦幼苗生理指标的影响

采用水培方法研究了镉(Cd)和苯并[a]芘(BaP)污染对小麦幼苗生理指标的影响。营养液中镉和苯并[a]芘的浓度分别为10mg.L-1和54mg.L-1。结果表明:与对照组相比,各胁迫组小麦生物量下降,株高降低,复合胁迫组地上及地下干重分别下降13.1%和49.8%,株高增长最低;各组超氧化物歧化酶(SOD)活性呈现升高-降低-升高趋势,且低于对照,过氧化物酶(POD)和过氧化氢酶(CAT)活性先升高再降低,复合胁迫组POD活性最高,CAT活性最低。镉、苯并[a]芘及其复合胁迫下,小麦幼苗的生长受到了一定抑制,且以复合胁迫最为显著。镉、苯并[a]芘联合作用的结果表现为协同促进作用。     

外源水杨酸对镉胁迫下玉米幼苗的叶氮素代谢和根系抗氧化酶的影响

采用溶液培养方法,研究不同浓度外源水杨酸(SA)对镉(Cd)胁迫下玉米幼苗的生长、光合色素的变化、叶片氮代谢及根系抗氧化系统酶活性的影响。结果表明,Cd胁迫抑制了玉米的生长发育和叶绿素合成,使硝态氮在叶中累积,同时影响了根系的抗氧化系统。应用50~250μmol·L-1浓度范围外源SA,叶绿素含量与胁迫情况下相比可提高81.3%、115.2%和45.9%,硝酸还原酶活性提高了1.32和1.29倍,降低了叶中硝态氮的含量30%,提高了谷氨酰胺合成酶(GS)和谷氨酸合成酶(GOGAT)活性60%以上,维持了氮素代谢过程的良好进行。外源50~250μmol·L-1SA可将玉米根系过氧化物酶(POD)活性减小至0.026 min·mg-1,POD和超氧化歧化酶(SOD)的活性与无Cd胁迫下的酶活性无显著差异,降低了Cd胁迫对质膜氧化系统的伤害。但外源SA对Cd胁迫的修复缓解作用受浓度的影响较大,低浓度的SA具有良好的修复效果,高浓度的SA反而影响了光合色素的合成以及酶的活性,抑制了玉米的生长。综合考虑各项指标,具有良好修复作用的外源SA浓度为50~100μmol·L-1。     

戊二醛胁迫对黑藻光合作用及抗氧化酶活性的影响

为探讨戊二醛对常见沉水植物的危害,用含有0、1、5、10、50 mg·L-1戊二醛的1/20 Hoagland营养液培养沉水植物黑藻,就不同浓度的戊二醛胁迫下黑藻叶绿素含量、光合速率、抗氧化酶（SOD、POD和CAT）活性和MDA含量变化进行试验研究。结果表明：戊二醛抑制叶绿素的合成或使其分解加速,叶绿素含量下降,光合速率下降;1、5 mg·L-1的戊二醛处理1 d和3 d后,SOD活性上升;1、5、10 mg·L-1的戊二醛处理1 d和3 d后,POD活性上升;经1 mg·L-1戊二醛处理后,CAT活性均处于较高水平,但当戊二醛浓度大于等于5 mg·L-1时,CAT活性与对照相比明显下降。经1 mg·L-1戊二醛处理,MDA含量没有明显变化;经5、10、50 mg·L-1戊二醛处理3 d后,MDA含量上升。低浓度戊二醛胁迫后能诱导黑藻的抗氧化酶活性增加,随着胁迫处理时间的延长和处理浓度的增大,抗氧化酶活性下降,但1 mg·L-1戊二醛处理7 d后,CAT活性没有下降,说明CAT对戊二醛的耐受能力较强。     

抗氧化酶在硝基苯中毒小鼠睾丸细胞凋亡中的作用

将10周龄雄性昆明小鼠随机分为硝基苯染毒组（26mg／kg、52mg／kg、105mg／kg）、花生油溶剂对照组、生理盐水对照组。对各组试验小鼠进行处理后，于第30d检测小鼠血清和睾丸中SOD、GSH-Px、CAT的活性及MDA含量，并通过DNA Ladder条带和透射电镜检测睾丸细胞的凋亡。结果，染毒组血清及睾丸中SOD、GSH—Px、CAT的活性显著或极显著（P〈0.01或P〈0．05）低于溶剂对照组，MDA含量显著或极显著（P〈0．01或P〈0，05）高于溶剂对照组，染毒组均显示DNA Ladder条带；电镜下细胞核皱缩，异染色质边聚，呈现典型凋亡现象。结果表明，硝基苯中毒能够诱使睾丸发生氧化应激，进而导致睾丸细胞发生凋亡，抗氧化酶在睾丸细胞凋亡中具有一定的作用。     

盐胁迫对鲁梅克斯杂交酸模种子萌发及幼苗生理特性的影响

为探究国外引进鲁梅克斯杂交酸模(Rumex patientia×R.tianschanicus cv.Rumex)对环境胁迫的适应性,以Na Cl为渗透介质模拟盐胁迫,对国外(材料1)和国内(材料2)两个不同来源鲁梅克斯的萌发率及幼苗期抗逆生理指标进行测定分析。结果表明,在不同浓度(0、50、100、150、200、250、300 mmol·L-1)Na Cl处理7 d后,材料1的萌发率明显高于材料2。在150 mmol·L-1Na Cl处理7、9、11、13和15 d后,材料1中超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性和过氧化氢酶(CAT)活性均显著高于(P0.05)材料2,但丙二醛(MDA)含量却显著低于(P0.05)材料2。表明材料1耐盐性强于材料2,更适于在盐渍土地上推广种植。     

Physiological Responses of Krishum (Iris lactea Pall. var. chinensis Koidz) to Neutral and Alkaline Salts

The aims of this study were to compare the physiological responses of krishum (Iris lactea Pall. var. chinensis Koidz) to neutral and alkaline salt stress and identify and examine the mechanisms involved in plant response to salt treatments. In this study, biomass, ion accumulation (Na⁺, K⁺, Ca²⁺, Mg²⁺), organic solute (proline) concentration, rate of membrane electrolyte leakage (REL) and antioxidase activities including those of superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6) and peroxidase (POD, EC 1.11.1.7) were investigated in krishum under different concentrations of NaCl, Na₂CO₃ and the mixture of the two salts in the same volume. All three treatments caused increases in Na⁺ concentration, proline content and REL and decreases in root Mg²⁺ and K⁺ content. Increased Ca²⁺ and antioxidase activities were observed at lower external Na⁺ concentrations. However, at higher external Na⁺ levels, decreased Ca²⁺ and antioxidase activities were detected. Alkaline salt resulted in more damage to krishum than neutral salt including lower SOD, POD and CAT activities and decreased proline content, relative to neutral salt. High Na⁺ and low K⁺ in krishum intensified ion toxicity under alkaline condition. Alkaline salt caused greater harm to plants than neutral salt, the primary reason of which might be the lower Ca²⁺ content in the plant under alkaline salt stress.     

外源甜菜碱对盐胁迫下黑果枸杞种子萌发和幼苗保护酶活性的影响

为了探究外源甜菜碱对盐胁迫下黑果枸杞(Lycium ruthenium)种子萌发及抗氧化物酶系活性的影响,对采自于河西走廊黑河中游的黑果枸杞进行种子萌发及幼苗生长试验,测定其发芽率(GP)、发芽势(GV)、发芽指数(GI)、活力指数(VI)、相对盐害率和抗氧化物酶系[超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)]等指标。结果显示,25mmol·L~(-1)的NaCl处理,对黑果枸杞种子的萌发具有促进作用,50~300mmol·L~(-1)的NaCl处理则有抑制作用;黑果枸杞种子萌发的NaCl浓度的临界值是50mmol·L~(-1),极限值是300mmol·L~(-1);随着NaCl浓度的增加,SOD、POD和CAT活性均不同程度地表现为"先上升,后下降"的趋势。在添加外源甜菜碱处理后,各NaCl浓度处理下的SOD、POD和CAT活性均有不同程度的增加。综上表明,甜菜碱能有效减缓盐胁迫对黑果枸杞种子萌发及幼苗生长产生的伤害,提高种子及幼苗的抗盐能力。     

淹水胁迫下美洲黑杨无性系生理生化指标的变化

 【研究目的】季节性淹水胁迫是滩地杨树造林的主要限制因子,建立可靠的指标体系对美洲黑杨无性系耐涝性进行评价意义重大;【方法】以美洲黑杨XL-75、XL-77、XL-90、I-69及苏柳J172为对象,分析了其内部生理生化指标对淹水胁迫的响应、性状间相关性及其遗传变异;【结果】淹水胁迫下各无性系叶绿素含量、可溶性蛋白质含量、CAT活性在总体上表现为下降的趋势;I-69杨在淹水胁迫下MDA含量较对照明显上升,XL-75、XL-77、XL-90、J-172在淹水初期MDA含量较对照略有下降,在后期出现回升的趋势;淹水15d时,5个参试材料SOD活性与对照比较均明显下降,随着淹水胁迫程度加深,SOD活性表现为依次上升趋势,而POD变化则与SOD恰好相反,二者存在明显的补偿机制;淹水30d以内时,5个参试材料ADH活性均较对照显著提高,淹水45d时,I-69杨ADH活性较对照下降56.9%,而XL-75、XL-77、XL-90、J172分别较对照提高970.4%、279.1%、555.2%和461.5%;【结论】不同处理下Chl、SOD、CAT相对值与总生物量相对值呈极显著正相关,且其广义遗传力在0.5967~0.7743之间,表明其受遗传控制程度较高,可做为不同无性系耐涝性评价的可靠指标。     

Effects of Resveratrol on in vitro Fertilization of Sheep Oocytes

The purpose of this study was to investigate the effects of resveratrol (RES) at different concentrations (0,0.5,2.0,5.0 μmol/L) on in vitro fertilization (IVF) and antioxidant capacity of ovine oocytes and the secretion of steroid hormones by cumulus cells.Sheep oocytes were fertilized in vitro after maturated in different concentrations of RES for 24 h,and the in vitro maturation (IVM) medium was collected for detecting the enzyme activity of superoxide dismutase (SOD),glutathione peroxidase (GSH-Px) and the content of monochrome display adapter (MDA).The ELISA method was used to detect the concentration of estradiol (E₂) and progesterone (P₄).The results showed that when compared to the control group,adding 0.5 μmol/L RES to the IVM medium significantly increased the cleavage rate (P<0.05),but had no significant effect on the fertilization rate and blastocyst rate (P>0.05);5.0 μmol/L RES significantly reduced the fertilization rate,cleavage rate and blastocyst rate (P<0.05),which had an inhibitory effect on embryonic development.Adding 0.5 μmol/L RES to IVM and IVC (in vitro culture,IVC) medium significantly increased the fertilization rate,cleavage rate and blastocyst rate (P<0.05).Compared to the control group,the addition of RES to IVM solution had a certain inhibitory effect on the secretion of E₂ by cumulus cells,5.0 μmol/L RES significantly reduced E₂ concentration (P<0.05);0.5 μmol/L RES significantly increased the P₄ secretion of cumulus cells (P<0.05).0.5 and 2.0 μmol/L RES increased the activity of SOD,GSH-Px and other enzymes,but there was no significant difference when compared with the control group (P>0.05),but significantly reduced MDA content (P<0.05),while 5.0 μmol/L RES significantly reduced the activity of antioxidant enzymes and increased the content of MDA (P>0.05).In conclusion,0.5 μmol/L RES simultaneously added to IVM and IVC medium could enhance the antioxidant capacity of oocytes and concentration of P₄,and reduced the content of MDA,thus improved the cleavage rate and blastocyst rate.     

肉鸡内毒素血症时血浆(清)抗氧化酶活性的变化及氨基胍对其的影响

将120只30日龄肉鸡(公母各半)随机均分为4组：对照组、内毒素组、氨基胍治疗组(内毒素 氨基胍)、氨基胍组。分别在试验后1、3、5、7、9h每组各宰杀6只。提取血浆(清)，检测血浆(清)中总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和谷胱甘肽还原酶(GR)活性以及丙二醛(MDA)含量的变化。结果显示，内毒素血症时总抗氧化能力降低，SOD、GR、GSH-Px的活性降低，MDA含量升高。而在氨基胍治疗组各项指标明显改善。由此表明，肉鸡内毒素血症时存在着明显的脂质过氧化作用，而氨基胍可以明显减轻内毒素所致的自由基诱导的脂质过氧化损伤。