牡丹皮、黄连、大黄提取物对松材线虫生理代谢的影响

对3种中草药黄连、牡丹皮、大黄的乙醇提取物毒杀松材线虫作用机制进行了初步研究。测定了其对线虫体内总糖和蛋白含量的影响, 处理前后线虫体内超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）、谷胱甘肽过氧化物酶（GSH-Px）和乙酰胆碱酯酶（AChE）酶活性变化和丙二醛（MDA）含量变化, 处理前后SOD、CAT、GSH-Px和AChE表达量变化; 并用松枝水培试验测定3种提取物对松材线虫病害的防控效果。结果表明, 提取物处理后线虫体内总糖及蛋白含量显著下降, 线虫体内糖及蛋白质的代谢受到干扰; 线虫体内SOD、CAT、GSH-Px酶活性提高, POD活性显著下降, MDA含量升高, 表明线虫体内氧化与抗氧化作用失衡, 细胞功能受到极大影响; AChE活性被抑制, 表明线虫的神经系统受到破坏, SOD、CAT、GSH-Px和POD表达量与酶活性变化基本一致。松枝水培试验表明中药提取物能够有效控制松材线虫病害发生。综上, 3种提取物引起的松材线虫体内众多生理指标的改变是造成线虫死亡的主要原因。     

球孢白僵菌次生代谢产物对南方根结线虫的作用机制初探

为明确球孢白僵菌Beauveria bassiana对南方根结线虫Meloidogyne incognita的作用机理,从线虫的活动频率、呼吸强度、体液渗透压、总糖含量、可溶性蛋白含量以及乙酰胆碱酯酶(AChE)活性几方面测定了球孢白僵菌Snef23菌株次生代谢产物对南方根结线虫2龄幼虫(J2)的影响。结果表明:Snef23次生代谢产物可抑制南方根结线虫J2的活动频率和呼吸作用,降低其乙酰胆碱酯酶活性,增强虫体内容物的渗漏,干扰J2体内糖和可溶性蛋白的代谢,从而达到毒杀致死作用。研究结果为探明球孢白僵菌杀线虫的作用机制提供了理论依据,可为更好地利用球孢白僵菌及其他天然产物防控植物的线虫病害提供参考。     

嗜菌异小杆线虫H06品系对红棕象甲解毒酶活性影响

为阐明嗜菌异小杆线虫H06品系对红棕象甲的作用机制,采用生物化学测定法研究了嗜菌异小杆线虫H06品系线虫接种红棕象甲幼虫后,对红棕象甲体内羧酸酯酶(CarE)、乙酰胆碱酯酶(AChE)和谷胱甘肽-S-转移酶(GST)活性的影响。结果表明,经嗜菌异小杆线虫H06品系侵染后,红棕象甲幼虫体内3种酶的活力均呈现先上升,后下降的趋势。其中处理后36 h,CarE活性比对照组升高43.15%,之后酶活力缓慢下降,至72 h时处理组酶活力比对照组降低29.55%;处理后36 h,AChE的酶活力比对照组增加79.42%,之后活力出现下降,至处理后72 h活力与对照组相比降低17.51%;对GST活力影响中,处理后12、24、36、48、60 h和72 h,红棕象甲GST酶活力水平与对照相比分别增加99.96%、62.28%、142.61%、145.81%、103.10%和38.39%。由此可知嗜菌异小杆线虫H06品系可通过干扰红棕象甲幼虫体内解毒酶的活性,从而达到对该虫致死的效果。     

松材线虫伴生细菌与松树萎蔫病关系的初步研究

利用马尾松水培离体松枝作接种材料,接种消毒后的松材线虫、线虫虫体上分离到细菌分离物GD1以及两者的混合体。结果表明,单独接种消毒后的松材线虫蔌细菌分离物GD1均不能使松枝萎蔫,只有两者混合接种才能使松枝发病枯死。从而说明了松材线虫的伴生细菌对松树萎蔫病的发生起着重要的作用。     

松材线虫rDNA-ITS1区分子检测与鉴定

利用两对松材线虫特异性引物,分别对来自日本、美国和葡萄牙的松材线虫虫样进行PCR检测,成功扩增出330 bp和220 bp rDNA-ITS1区基因片段,该方法对松材线虫成虫或幼虫均能作出准确鉴定.     

二氧化碳浓度和温度升高对烟粉虱主要保护酶和解毒酶活性的影响

为明确烟粉虱Bemisia tabaci(Gennadius)在大气CO2浓度和温度双因子胁迫下的生理响应,以CO2浓度和温度为作用因子,研究了4种不同组合处理下烟粉虱成虫体内超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、谷胱甘肽转移酶(GST)、乙酰胆碱酯酶(Ach E)活性的变化。结果表明:常温处理下,CO2浓度升高烟粉虱体内POD和GST活性分别增加87.6%和295%,SOD和CAT活性分别降低22.4%和28.2%;高温处理下,CO2浓度升高烟粉虱体内Ach E和GST活性分别增加103.6%和167.5%,CAT活性降低31.6%;常CO2浓度处理下,温度升高烟粉虱体内POD和SOD活性分别增加46.2%和18.2%,CAT活性降低35.8%;高CO2浓度处理下,温度升高烟粉虱体内Ach E和SOD活性分别增加75.3%和40.3%,CAT活性降低38.9%。表明CO2浓度和温度升高是导致烟粉虱体内SOD、POD、GST和Ach E活性升高的主要原因,并且SOD和POD活性变化受到CO2和温度的交互影响。烟粉虱可能通过改变体内保护酶或解毒酶的活性来适应CO2浓度和温度升高的环境。     

36种中草药提取物杀松材线虫活性研究

为了从中草药中寻找高效杀线虫活性物质,本文测定了36种中草药提取物对松材线虫及其卵的毒杀活性。结果表明,牡丹皮、黄连和大黄3种中药的乙醇提取物杀线虫活性较强,以提取物浓度为10 g/L处理松材线虫72 h后,校正死亡率均为100%。3种中药提取物处理松材线虫72 h后半致死浓度（LC50）分别为1.81、0.2638和1.07 g/L。杀卵活性结果表明,3种中药提取物处理72 h后,线虫卵的孵化率均低于20%,虫卵的校正死亡率均高于60%。利用乙酸乙酯和水作溶剂对3种中草药进行初步的杀线活性成分分离的结果表明,牡丹皮的杀线活性物质存在于乙酸乙酯萃取物中,黄连和大黄的杀线活性物质存在于水萃取物中。3种中药的不同萃取物处理松材线虫72 h后的LC50分别为0.712、2.370和0.067 g/L。     

异硫氰酸甲酯和硫酰氟混用杀灭松材线虫的增效研究

松萎蔫病由松材线虫(pine wood nematode,PWN,Bursaphelenchus xylophilus)引发并在世界范围内广泛发生,是对松树威胁最大的病害之一.本文使用不同比例的硫酰氟(sulfuryl fluoride,SF)和异硫氰酸甲酯(methyl isothiocyanate,MITC)混剂对木包装中的松材线虫进行了熏蒸.结果表明,75.5 g/m3硫酰氟在20℃单独熏蒸24 h才可杀灭99%的松材线虫,而添加2.5%,5%,10%,20%质量比的异硫氰酸甲酯后,分别只需硫酰氟11.8 g/m3,8.72 g/m3,5.49 g/m3,3.75 g/m3即可在同等条件下杀灭99%的松材线虫,说明异硫氰酸甲酯对硫酰氟杀灭松材线虫存在明显增效.     

松材线虫自然侵染后松树感病进程中光合作用及抗氧化酶活性的变化

根据松树针叶变色程度及流脂状况,野外分别选取不同感病阶段的黑松、马尾松为对象,以研究松材线虫自然侵染黑松和马尾松后,两种松树的光合作用及其相关生理生化变化过程。结果表明,黑松、马尾松在感病初期,针叶净光合速率(Pn)大于健康阶段数值,随后逐渐下降,感病重期为负值,即松材线虫的侵入破坏了黑松、马尾松的光合作用。由叶绿素荧光参数分析可看出,光合作用的下降是由于光合系统Ⅱ反应中心实际进行光化学反应的效率(ФPSⅡ)下降引起的,而ФPSⅡ的下降是由于PSⅡ反应中心捕获光能效率Fv'/Fm'下降和开放的PSⅡ中心数目qP下降共同导致。两种松树在感病进程中,针叶叶绿素含量和类胡萝卜素含量整体呈下降趋势,但在感病初期含量上升,这也是引起光合作用速率下降的因素之一。此外,针叶含水量变化也一直呈下降趋势,是引起松树萎蔫,叶绿素含量下降,光合作用速率下降的主要原因之一。实验表明,随着松材线虫侵染的加重,植株体内与抗性相关的抗氧化酶系统活性也会发生变化。黑松和马尾松过氧化氢酶(CAT)活性随着感病进程逐渐下降,过氧化物酶(POD)活性和超氧化物歧化酶(SOD)活性略有上升,但不显著,说明松材线虫的侵入破坏了黑松、马尾松的抗氧化酶系统,导致松树自我保护作用减弱,同时由于两种松树热耗散能力(NPQ)的下降,产生的多余电子进一步破坏了抗氧化酶系统,导致光合速率下降。研究表明,松材线虫的侵染,对寄主光合作用产生了破坏,同时寄主也作出相应防御反应,但随着松材线虫的大量繁殖,寄主自身保护作用逐渐丧失。     

感染松材线虫病松树滑刃目线虫调查

 本研究首次在全国范围内调查感染松材线虫病松树体内滑刃目线虫的种群组成,包括种类记述和数量组成分析。结果表明:在300份样品中共分离得到10种滑刃目线虫,隶属于3科、4属,其中有2个国内新记录种;它们是松材线虫、拟松材线虫、霍夫曼尼伞滑刃线虫、薄荷滑刃线虫、大核滑刃线虫、小麦长尾线虫(国内新记录种)、爱尔密那长尾线虫(国内新记录种)、李氏长尾线虫、吴氏长尾线虫和外滑刃科线虫一种;描述并且图示比较它们的形态特征。种群数量组成分析表明:松材线虫在感病松树体内占据绝对的优势,削弱了松树线虫群落组成的多样性,即线虫群落结构趋向单一化。研究还表明,利用长尾属线虫的捕食习性来控制中国松材线虫病的流行与危害值得进一步探索与研究。     

Biochemical effects of acute phoxim administration on antioxidant system and acetylcholinesterase in Oxya chinensis (Thunberg) (Orthoptera: Acrididae)

The study was undertaken to evaluate the effects of different concentrations of phoxim on acetylcholinesterase (AChE) and esterase (EST) activities, and antioxidant system after topical application to Oxya chinensis. The results showed that phoxim inhibited AChE activity, and did not cause significant changes in the EST activity and the levels of malondialdehyde (MDA) and reduced glutathione (GSH). After phoxim administration, superoxide (SOD) and catalase (CAT) activities showed a biphasic response with an initial increase followed by a decline in their activities. Glutathione reductase (GR) and glutathione peroxidase (GPx) activities were inhibited in comparison with the control. Glutathione S-transferase (GST) activity showed irregular changes. Its activity increased significantly at the concentrations of 0.06 and 0.12 μg/μL and decreased at the concentrations of 0.09 and 0.24 μg/μL compared with the control. Changes in SOD, CAT, GST, GPx, and GR activities indicated that phoxim caused oxidative damage in O. chinensis. However, no significant changes in MDA content suggested that these enzymes played important roles in scavenging the oxidative free radicals induced by phoxim in O. chinensis. The formation of oxygen free radicals might be a factor in the toxicity of phoxim.     

Protective effects of Nigella sativa oil on propoxur-induced toxicity and oxidative stress in rat brain regions

Propoxur (PPr) is a widely used broad spectrum carbamate insecticide mainly used to control household pests. Because of the widespread use of pesticides for domestic and industrial applications, evaluation of their neurotoxic effects is of major concern to public health. The aim of the present study was to evaluate the possible protective effects of Nigella sativa oil (NSO), an antioxidant agent, against PPr-induced toxicity and oxidative stress in different brain regions of rats including cerebellum, cortex and hippocampus. In the present study, 32 male Sprague-Dawley rats were used and divided into four equal groups. Group 1 was allocated as the control group. Groups 2-4 were orally administered 1 ml/kg/bw/day NSO, 8.51 mg/kg/bw/day PPr or NSO plus PPr, respectively, for 30 days. Lipid peroxidation (LPO), protein carbonyl content (PCC) and acetylcholine esterase activity (AChE) were determined. Enzymatic antioxidant activities [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST)] and non-enzymatic antioxidants [reduced glutathione (GSH)] were determined. PPr treatment significantly increased the levels of LPO, PCC and oxidized glutathione (GSSG) in brain regions. On the contrary, levels of GSH and the activities of SOD, CAT, GSH-Px, GST and AChE were significantly decreased. NSO treatment to PPr intoxicated rats restored such biochemical parameters to within control levels except GST activity, emphasizing its antioxidant role. We conclude that NSO significantly reduces PPr-induced toxicity and oxidative stress in rat brain regions via a free radicals scavenging mechanism.     

八种十字花科寄主植物真叶和子叶的化学成分及其对小菜蛾生长发育及生理代谢的影响

为明确小菜蛾Plutella xylostella对寄主植物真叶和子叶的适合度,于室内测定8种十字花科植物改良青杂3号、改良露头青、陕油0913、甘杂1号、超级火箕青、四月慢、绿球66和中花尖叶芥蓝真叶和子叶的营养物质和次生代谢物质的含量,并测定取食后小菜蛾幼虫的取食选择性、发育历期、蛹重、保护酶和解毒酶活性。结果显示,8种寄主植物真叶的可溶性糖、总氨基酸、单宁、类黄酮和总酚含量之间差异显著,且大部分均显著高于其子叶,8种寄主植物子叶的可溶性糖、总氨基酸、单宁、类黄酮和总酚含量之间也差异显著。小菜蛾3龄幼虫偏好取食真叶;取食8种寄主植物真叶后成虫前期的发育历期为12.3～16.3 d,取食子叶后成虫前期的发育历期为14.3～18.6 d;取食子叶的蛹重明显低于取食其真叶;取食8种寄主植物真叶的小菜蛾幼虫体内超氧化物歧化酶（superoxide dismutase,SOD）、过氧化物酶（peroxidase,POD）、过氧化氢酶（catalase,CAT）、谷胱甘肽S-转移酶（glutathione S-transferase,GST）、羧酸酯酶（carboxylesterase,Car...     

寄主植物对二斑叶螨解毒酶活性的诱导作用

[目的]明确不同蔬菜寄主对二斑叶螨解毒酶活性的诱导影响,为叶螨的寄主适应性及叶螨对寄主的抗性机制研究提供基础.[方法]将饲养在菜豆上的二斑叶螨分别转移到黄瓜、甘蓝和茄子上饲养3代后,测定包括菜豆在内的4种不同寄主植物对叶螨体内解毒酶系活性的诱导影响.[结果]取食不同寄主植物的二斑叶螨体内解毒酶系活性差异显著.从菜豆寄主转养到黄瓜、甘蓝和茄子上后,后3个寄主上叶螨种群体内谷胱甘肽S-转移酶(GST)活性显著下降,茄子上种群活性最低,菜豆种群是茄子种群的2.75倍;而后3个寄主种群的乙酰胆碱酯酶(AChE)比活力显著上升,茄子种群最高,是菜豆种群的6.03倍.4种供试寄主植物的二斑叶螨种群中,在黄瓜寄主上羧酸酯酶(CarE)和多功能氧化酶(MFO)活性显著高于其他3种寄主植物,CarE活性的高低顺序为黄瓜＞菜豆和甘蓝＞茄子,而MFO活性为黄瓜＞茄子和菜豆＞甘蓝.[结论]取食不同寄主植物可诱导二斑叶螨体内的解毒酶系活性发生不同程度的变异,这可能是二斑叶螨对寄主具有广泛适应性的生理基础之一.     

Effects of trichlorfon and sodium dodecyl sulphate on antioxidant defense system and acetylcholinesterase of Tilapia nilotica in vitro

The effects of organophosphorus insecticide trichlorfon, surfactant sodium dodecyl sulphate (SDS), and the mixture of trichlorfon and SDS on the antioxidant defense system and acetylcholinesterase (AChE) in Tilapia nilotica were assessed in vitro. Various concentrations of trichlorfon (0, 0.0001, 0.001, 0.01, 0.1 and 1 g/L) and SDS (0, 0.0625, 0.125, 0.25, 0.5, 1 g/L) were incubated with homogenate of liver and muscle, respectively, at 25 °C for 0, 30, 60 and 90 min. Two concentrations of mixture of trichlorfon and SDS (0.0001 g/L trichlorfon + 0.5 g/L SDS, 0.1 g/L trichlorfon + 0.5 g/L SDS) and 0.0001 g/L trichlorfon, 0.1 g/L trichlorfon, 0.5 g/L SDS and control, were incubated simultaneously with homogenate of liver and muscle, respectively, at 25 °C for 60 min. After incubation, the content of reduced-glutathione (GSH) and the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) in homogenate of liver were determined, and the activities of AChE in homogenate of muscle were also measured.Treatment with trichlorfon caused a significant concentration-dependent and time-related inhibition of AChE activity at all treatment concentrations and times since trichlorfon is a cholinesterase inhibitor. For the same trichlorfon treatment, an apparent decrease in GSH content was found in concentration of 0.01, 0.1, 1 g/L, whereas no significant alteration in antioxidant enzyme activity were found at all experiment concentrations and times, which might indicate that antioxidant enzymes have not involved in the metabolism of trichlorfon. The depletion of GSH might indicate that ROS could be involved in the toxic effects of trichlorfon. Exposure of SDS can inhibit activities of AChE, GST and CAT at concentrations of 0.5 and/or 1 g/L, which could be due to the denaturing process of SDS to the enzymes. For the mixture exposure of trichlorfon and SDS, the effect of the mixture of 0.0001 g/L trichlorfon and 0.5 g/L SDS on inhibition of AChE shows synergistic other than simple additive of trichlorfon and SDS. The combined effects of chemicals and detergents deserve to be particularly noted. It should be noted that the toxicity experiments were made in tissue homogenates instead of whole organisms. The responses against the toxic compounds will not be the same in both systems.     

天维菌素酰化衍生物的合成及杀虫杀螨活性

以天维菌素B、天维菌素B单糖苷和天维菌素B苷元为原料,经选择性C-5羟基保护,在C-13、C-4′和C-4″位引入不同酰基基团,合成了3个系列共23个天维菌素B酰化衍生物,并通过1H NMR、13C NMR和高分辨质谱对所有目标化合物的结构进行了表征。生物活性测定结果表明,所有衍生物对小菜蛾Plutella xylostella、朱砂叶螨Tetranychus cinnabarinus以及松材线虫Bursaphelenchus xylophilus均表现出不同程度的毒杀活性,其中天维菌素B C-4″位衍生物的活性优于C-4′位衍生物及13位衍生物。化合物8e对小菜蛾和松材线虫的毒杀活性最优,LC50值分别为9.2 mg/L和0.42 mg/L,化合物8b对朱砂叶螨的毒性最高,LC50值为0.0019 mg/L,均优于对照药天维菌素B。     

虫酰肼对甜菜夜蛾六类酶活性的影响

用一个采自武汉地区的甜菜夜蛾田间种群(N)和一个相对敏感种群(CK),比较了甜菜夜蛾的表皮酚氧化酶(PPO)、乙酰胆碱酯酶(TCE)、谷胱甘肽-S转移酶(GST)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)酶活力差异。用含有0.14mg/kg(致死中量)虫酰肼的带毒饲料处理CK种群的甜菜夜蛾,处理后24、48h和72h测定酶活力,结果与CK种群相比,PPO酶活力分别降低79.12%、10.54%和56.23%;SOD酶活力分别上升71.59%、63.16%和79.55%;GST酶活力在处理后24h酶活力上升41.43%。N种群与CK种群比,PPO酶活力降低38.47%;GST酶活力升高34.20%。采用PAGE凝胶电泳方法比较了CK、N和用虫酰肼分别汰选CK种群4代和6代的甜菜夜蛾种群酯酶同工酶谱差异。结果表明,CK共有15条酯酶同工酶带,N和汰选种群均只有10条带。研究结果初步表明甜菜夜蛾对虫酰肼的抗药性可能与PPO、GST、SOD、EI酶活力变化有关,与CAT关系不大,与TCE无关。