铝胁迫对黑大豆膜脂过氧化及抗氧化酶活性的影响

以耐酸型黑大豆(丹波黑大豆,简称RB)和酸敏感型黑大豆(简称SB)为材料,在水培条件下分析不同浓度的铝胁迫对这两种黑大豆叶和根膜脂过氧化和抗氧化酶活性的影响。结果显示:RB的铝耐受能力比SB强;在不同浓度铝胁迫下RB叶和根中的H2O2和MDA上升幅度低于SB,SB的叶和根中膜脂过氧化程度大于RB。在不同浓度铝胁迫下,RB叶和根中的SOD活性与SB差异不大,而CAT活性在RB和SB的叶和根中均被诱导显著升高,POD活性在RB叶和根中有下降趋势但仍然显著高于SB。因此,与酸敏感型的黑大豆相比,耐酸型黑大豆在铝胁迫下具有较强的保护酶活性,使其膜脂受氧化损伤的程度较低,从而表现出更强的耐铝胁迫能力。     

镉胁迫对旱柳细胞膜透性和抗氧化酶活性的影响

以‘Fuyang 3’旱柳为材料,通过水培方法研究了中、高剂量(5、25μmol.L-1)镉胁迫下旱柳器官的镉(Cd2 )积累、叶和根细胞膜渗透及抗氧化酶活性的变化。结果表明:Cd2 主要积累在旱柳的根部(最高达1 297.71μg.g-1),其次是枝条(最高为163.13μg.g-1)。中、高剂量Cd2 胁迫下,旱柳叶相对电导率、根K 渗透以及根和叶丙二醛(MDA)含量均未发生显著变化。中、高剂量Cd2 胁迫使旱柳根系的超氧歧化酶(SOD)、抗坏血酸过氧化物酶(APX)和谷胱甘肽转移酶(GST)活性,以及叶片的SOD、愈创木酚过氧化酶(POD)、谷胱甘肽过氧化物酶(GPX)和GST活性均比对照显著增强;且高剂量胁迫旱柳根系的SOD和GST活性,及其叶片的POD、GPX和GST活性均显著高于相应中剂量胁迫。研究发现,旱柳在不同浓度镉胁迫条件下,其根是Cd2 主要积累器官,其叶和根细胞质膜能保持相对稳定性,其根和叶各抗氧化酶活性发生不同程度改变,从而使旱柳对Cd2 胁迫表现出一定的忍耐性。     

低温胁迫下钼对冬小麦抗氧化防御系统及膜脂过氧化的影响

研究了低温（0～5℃）胁迫下钼对冬小麦抗氧化系统和膜脂过氧化的影响。结果表明,低温胁迫下施钼植株电解质渗漏率和丙二醛含量显著降低。施用钼肥提高了冬小麦叶片中抗氧化酶类如超氧化物歧化酶（SOD,EC1．15．1．1）、过氧化物酶（POX,EC1．11．1．7）和过氧化氢酶（CAT,ECl．11．1．6）的活性。低温胁迫下施钼对抗氧化酶（SOD、POX和CAT）活性提高幅度比常温下高。不论常温还是低温下,施铝均提高了冬小麦叶片中抗坏血酸和脯氨酸含量,低温胁迫下提高幅度更大。常温下缺钼和施钼处理后,叶片中类胡萝卜素含量差异不显著;低温下施钼后,冬小麦叶片类胡萝卜素含量显著增加。因此,低温胁迫下施钼植株活性氧清除能力增强、细胞膜伤害减轻可能是冬小麦抗寒力提高的原因之一。     

臭氧浓度升高对油松抗氧化系统活性的影响

以生长在开顶箱内的油松为试材,对高浓度臭氧(80 nmol·mol^-1)条件下油松(Pinus tabulaeformis)针叶中超氧阴离子自由基(O₂^·)产生速率、过氧化氢(H₂O₂)含量、超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶、脱氢抗坏血酸还原酶、单脱氢抗坏血酸还原酶、谷胱甘肽还原酶活性与抗坏血酸(ASA)含量进行测定.结果表明:高浓度臭氧使O₂^·产生速率提高,H₂O₂ 和MDA含量增加.ASA含量与SOD、抗坏血酸过氧化物酶、脱氢抗坏血酸还原酶、单脱氢抗坏血酸还原酶、谷胱甘肽还原酶活性在高浓度臭氧熏蒸的前期升高,随后下降并低于对照.说明生长季前期,油松抗氧化系统对高浓度臭氧存在适应性反应,但不能抵抗长期臭氧胁迫带来的氧化伤害.     

西藏飞蝗的生物学特性

西藏飞蝗Locusta.migratoria tibetensis Chen在四川甘孜州1年发生1代,某些地方(乡城县)1年发生不完整的2代,即以卵越冬,翌年3月下旬开始孵化出土,4月中、下旬为孵化盛期,1~3龄始盛期为4月中旬~5月中旬,高峰期为5月下旬,7月上旬初始羽化,7月下旬~8月上旬为羽化盛期,8月上旬始见产卵,8月下旬~9月上旬为产卵盛期,第1代成虫较早产下的卵块在条件适宜的情况下可于当年9月上旬孵化出土,但孵化出的蝗蝻不能越冬。该虫卵、全蝻期及全世代的发育起点温度分别为14.2,16.1,14.6℃,有效积温为179.1日.度、360.0日.度、787.8日.度。在18,21,24,27和30℃等5种恒温条件下其平均世代历期214.4,133.3,79.2,66.3和50.7d。     

西藏飞蝗触角感器的扫描电镜观察

应用扫描电镜对西藏飞蝗Locusta migratoria tibetensis Chen触角的外部形态结构及其感器进行了观察和研究.结果表明,西藏飞蝗触角上存在5种感器即毛形感器、刺形感器、腔锥形感器、锥形感器和腔形感器.通过对各种感器的形态特点进行描述,发现西藏飞蝗群居型与散居型、蝗蝻与成虫、雌性与雄性的感器在类型...     

温度胁迫对小金蝠蛾幼虫抗氧化酶活性的影响

小金蝠蛾Hepialus xiaojinensis Tu.是我国名贵中药材冬虫夏草的寄主昆虫之一,适宜在高海拔低温地区(8℃-12℃)生存。本文研究了小金蝠蛾在不同温度(4℃、12℃、16℃、20℃、24℃、28℃)条件下处理4 h和12 h后4龄幼虫体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、谷胱甘肽硫转移酶(GSTs)的活力变化,以及总抗氧化能力(T-AOC)和丙二醛(MDA)含量的变化。结果表明,小金蝠蛾在正常生长发育情况下SOD具有较高活性;经温度胁迫后,SOD活力持续维持在较高活性,CAT、POD活性以及T-AOC活性显著性升高(P0.05);GSTs在24℃以上活性有降低趋势,MDA含量有上升趋势。     

西藏飞蝗各发育阶段的耐寒性

西藏飞蝗Locusta migratoria tibetensis Chen是青藏高原的重要农牧业害虫。对该虫各发育阶段的过冷却点和结冰点的测定表明,西藏飞蝗卵的过冷却点和结冰点为最低,分别为-22.02℃、-16.36℃,4龄蝻的过冷却点和结冰点最高,分别是-6.46℃和-5.05℃,西藏飞蝗在甘孜以卵越冬。     

西藏飞蝗（Locusta migratoria tibetensis Chen）耐寒性理化指标

西藏飞蝗是青藏高原上的一种重要害虫.近年来, 西藏飞蝗在西藏、青海玉树以及川西高原上危害十分严重.通过对该虫各发育阶段过冷却能力测定,研究了各发育阶段虫体内生理生化物质与过冷却能力之间的关系,揭示了该虫耐寒性规律.结果表明,西藏飞蝗蝗卵的过冷却点和结冰点为最低,分别为-22.02℃和-16.36℃.在1～4龄蝗蝻期,过冷却点随体内水分、糖原和脂肪含量随着虫体的发育而升高,其过冷却点分别为-9.28℃、-8.51℃、-7.18℃、-6.46℃;到5龄蝗蝻时,虫体脂肪和糖原含量达最高值,过冷却点下降为-8.07℃.讨论了虫体脂肪、糖原和甘油含量变化与其耐寒力之间的关系.     

散居型西藏飞蝗九个地理种群形态特征的数量分析

为阐明西藏飞蝗Locusta migratoria tibetensis Chen散居型地理种群数量性状的地理变异,将散居型西藏飞蝗9个地理种群雌、雄个体的前翅长度(E)、后足股节长度(F)、头宽(C)、前翅长度与后足股节长度比值(E/F)、后足股节长度与头宽比值(F/C)5项形态特征参数进行系统聚类分析和主成分分析....     

1961-2005年西藏飞蝗潜在分布的变化

青藏高原是气候变暖的敏感地区, 温度是影响青藏高原昆虫分布的重要因素。作为青藏高原的本地物种的蝗虫, 西藏飞蝗Locusta migratoria tibetensis Chen对高原升温的反应就是获得的有效积温增加, 分布范围扩大。为了准确估计西藏飞蝗发生面积, 以期为西藏飞蝗监测、 预警及控制提供依据, 本研究以1961－2005年90个高原气象站点地面温度资料计算了西藏飞蝗的有效积温(accumulated degree-days, ADD), 建立了1961－2005年有效积温与地理位置的模型; 并根据这些模型利用GIS技术, 计算了各年西藏飞蝗的潜在分布面积(area of potential distribution, APD)。结果表明： 温度升高能明显增加西藏飞蝗获得的有效积温, 西藏飞蝗的分布主要沿高原河谷分布。1961－2005年, 西藏飞蝗平均潜在分布面积为91 081 km², 约占高原面积3%; 次热年1998年西藏飞蝗的潜在分布面积最大, 达142 988 km², 是最冷年1968年的1.9倍。相关分析表明： 西藏飞蝗潜在发生面积与年平均地面温度显著相关。趋势线分析表明： 45年间青藏高原每年平均增温0.0301℃, 而西藏飞蝗潜在发生面积平均每年增加504.38 km², 两者之比为16 756.8, 温度的增加能够引起西藏飞蝗潜在分布面积大幅上升。本文为全球气候变暖对青藏高原生态的影响提供了事例依据。     

Response of Locusta migratoria tibetensis Chen (Orthoptera: Acrididae) to climate warming over the Tibetan plateau

As a region with one of the most important terrestrial ecosystems, the Tibetan plateau is both sensitive to and vulnerable to climate warming. Locusta migratoria tibetensis Chen, an endemic species on the Tibetan plateau, is likely to be affected by climatic warming. In our studies, accumulated degree‐days (ADD) of L. Migratoria T.C. were calculated based on data from 90 weather stations over the Tibetan plateau from 1961 to 2005. Trend lines show that across weather stations, ADD increased at a rate of 1.17 DD/a during climate warming. The majority of weather stations (82.2%) showing increases in ADD were located towards the west of the Tibetan plateau. At higher elevations, the increase in the ratio of annual ADD to the station mean ADD was higher relative to those at lower elevations. A linear regression model between ADD and geographical position was established to create raster maps of ADD in ArcGIS 9.2. The area of potential locust distribution (APD) was estimated to be 42 420 km², mostly distributed along major rivers on the Tibetan plateau. In warmer years, the APD increased sharply over study periods. A new area of potential distribution would appear in the north Tibetan plateau if the climate warming continued. In the south‐east Tibetan plateau, the locust would expand its range northwards or westwards along the river valleys, and the locust APD would also rise in elevation.     

The in vitro effect of temperature on motility and antioxidant response of common carp Cyprinus carpio spermatozoa

The effect of temperature on Cyprinus carpio spermatozoa in vitro was investigated with spermatozoa activated at 4, 14, and 24 °C. At 30 s post-activation, motility rate was significantly higher at 4 °C compared to 14 and 24 °C, whereas highest swimming velocity was observed at 14 °C. The thiobarbituric acid-reactive substance (TBARS) content was significantly higher at 14 °C and 24 °C than at 4 °C in motile spermatozoa. No significant differences in catalase and superoxide dismutase activity relative to temperature were observed. This study provides new information regarding effect of temperature on lipid peroxidation intensity and spermatozoon motility parameters in carp. The elevation of TBARS seen at higher temperatures could be due to inadequate capacity of antioxidant enzymes to protect the cell against the detrimental effects of oxidative stress induced by higher temperatures.     

Effects of temperature and [His7]-corazonin on the body darkening in Locusta migratoria

Abstract.  [His⁷]-corazonin is a neuropeptide that induces dark coloration in locusts. This study examined the effect of temperature on body colour in the migratory locust, Locusta migratoria . L. Injection of a low dose (1 pmol) of [His⁷]-corazonin caused albino nymphs to develop dark coloration at 25–34 °C, but little darkening occurred at 38 and 42 °C. However, injection of a high dose (10 pmol) induced darkening even at these high temperatures. Transfer of nymphs injected with 1 pmol of [His⁷]-corazonin from 30 to 42 °C, and vice versa, indicated that temperature influenced darkening at any time after injection. Measurements of the luminance of the pronotum were made using commercially available computer software to follow continuous changes in darkening of the body. The body colour of nymphs injected with [His⁷]-corazonin was reddish-brown at 25 °C, blackish at 30 and 34 °C, and greyish or whitish at 38 and 42 °C. High temperature also suppressed darkening in a normal (pigmented) strain. Most nymphs transferred from 30 to 42 °C during the first three stadia developed a light colour in the fifth stadium without the striking black patterns that are typically manifested in gregarious nymphs at lower temperatures. Such individuals developed black patterns in the fifth stadium when injected with [His⁷]-corazonin at a mid stage of the previous stadium. These results indicate that high temperature may induce light body coloration by suppressing the release of [His⁷]-corazonin in normal locusts.     

Effects of vanadate on male rat reproductive tract histology, oxidative stress markers and androgenic enzyme activities

Vanadium has been recognized as industrial hazards that adversely affect male reproductive systems of humans and animals. However, less information is available concerning the underlying mechanism in the pathogenesis of male reproductive dysfunction. The present study investigated the possible involvement of oxidative stress to induce oxidative deterioration of testicular functions in adult rats. The results of in vitro and in vivo studies demonstrate that vanadium treatment resulted in a significant dose- and time-dependent increase in the testicular lipid peroxidation, marked inhibition in the level of superoxide dismutase and catalase activities, decreased sperm counts, and substantially inhibited the activities of Delta(5)3beta- and 17beta-hydroxysteroid dehydrogenase as well as serum testosterone level. Histopathological examination revealed inhibition of spermatogenesis and the preferential loss of maturing and elongated spermatids along with increased percent of abnormal sperm. Taken together, the results suggest that an increase in free radical formation relative to loss of antioxidant defense system during vanadium exposure may render testis more susceptible to oxidative damage leading to their functional inactivation. Thus the toxic effects of vanadium are cumulative and that vanadium produced damages in testes are dose- and time-dependent.     

Oxidative stress and antioxidant defense responses by goldfish tissues to acute change of temperature from 3 to 23 °C

The effects of a rapid transfer from a low (3 °C) to a warm (23 °C) temperature on oxidative stress markers and antioxidant defenses were studied in the brain, liver and kidney of the goldfish, Carassius auratus. Cold-acclimated fish were acutely moved to 23 °C and sampled after 1, 6, 12, 24, 48 or 120 h of warm temperature exposure. Lipid peroxide levels increased quickly during the first few hours at 23 °C, but thiobarbituric acid-reactive substances changed little. Protein carbonyl content was reduced by 20–40% in the liver over the entire experimental course, but increased transiently in the kidney. The content of high-molecular mass thiols decreased by two-thirds in the brain and was affected slightly in other organs. By contrast, total low-molecular mass thiols (e.g. glutathione and others) increased transiently. Activities of the primary antioxidant enzymes—superoxide dismutase and catalase—were generally unaffected in goldfish organs, whereas glutathione-dependent enzymes were elevated in the brain and kidney after 24–48 h at 23 °C. Glutathione peroxidase increased by 1.5–2.3-fold and glutathione-S-transferase by 1.7-fold. Hence, a short-term exposure to warm temperature disturbed several oxidative stress markers, but only slightly affected the activities of antioxidant enzymes. However, comparison of the current data for cold-acclimated winter fish with the same parameters in summer fish suggests that longer exposure to high ambient temperature requires the enhancement of activities of glutathione-dependent enzymes for maintaining the steady-state levels lipid peroxidation and protein oxidation in goldfish tissues.     

亚洲飞蝗发声器结构与鸣声时域特征研究

本文对亚洲飞蝗Locusta migratoria migratoria(L.)发声器的结构及鸣声的时域特征进行了研究.亚洲飞蝗主要的发声方式为前翅中闰脉-后足股节型,即前翅中闰脉的发声齿与后足股节内侧隆线相互摩擦发出鸣声.应用扫描电子显微镜技术对发声器的结构进行观察,结果表明,亚洲飞蝗前翅中闰脉具有单排规则排列的发声...