青海沙棘果粉抗氧化活性的研究

为了深入了解青海沙棘果粉的品质,助其实现规模化生产,从1,1-二苯基苦基苯肼自由基(DPPH·)体系、羟基自由基(·OH)体系、超氧阴离子自由基(O-2·)体系和亚硝酸盐(NO-2)的清除效果方面着手,研究了其体外清除自由基活性。结果表明,青海沙棘果粉对DPPH·、·OH、O-2·和NO-2均有清除作用,且对DPPH·、·OH的清除能力优于O-2·和NO-2。     

miR482介导的植物生物胁迫响应

植物在生长发育过程中会遇到各种生物胁迫,根据响应过程的不同,可将之分为基于蛋白质的生物胁迫和基于RNA的生物胁迫。miR482是一种植物特有的、已在23个物种中被证实存在的小RNA。miR482参与指导植物次级phasiRNA的合成,其主要靶标为植物庞大的Ⅳ=日§三R尺类家族抗病基因。本文通过整理近年来ETI（effector-triggeredimmunity）相关的NBS-LRR类抗病基因和抗RNA沉默抑制相关miR482级联调控的研究成果,总结出了miR482介导植物两类生物胁迫响应的调控机制。     

我国森林脑炎病毒森张株编码区序列测定

为鉴定我国森林脑炎病毒亚型,了解基因组结构与生物功能的关系,同时为森林脑炎病毒新型疫苗研制打下基础,对森林脑炎病毒森张株编码区序列进行测定.根据已发表的Sofjin-HO、Oshima5-10株序列设计9对重叠引物,通过RT-PCR扩增不同的cDNA片段,分别克隆至pGEM(R)-T载体,转化DH5 α菌,挑阳性克隆PCR、酶切鉴定后测序.结果表明森张株编码区全长10 245nt,编码3 414个氨基酸.我国森林脑炎病毒森张株与Oshima5.10、Sofjin-HO、Sofjin同源性最近,属于远东亚型.     

灰树花提取物清除氧自由基的研究

采用化学发光法比较了灰树花各提取物对超氧阴离子自由基、羟基自由基的清除效果。研究结果表明,灰树花子实体和菌丝体的提取物对羟基自由基均有很好的清除作用,灰树花菌丝体水提物(GFME)、灰树花子实体水提物(GFE)、灰树花子实体水提多糖(GFP)、灰树花子实体碱提多糖(GFAP)清除羟基自由基的IC50均小于1.0 mg/mL,其他提取物清除羟基自由基的IC50也均小于3.0 mg/mL。而对超氧阴离子自由基仅GFME、GFMP、GFE有清除作用,其他的提取物清除作用很弱。     

Effect of Light on Scavenging Capacity for Organic Free Radical in Leaves of Four Woody Plants

Change of antioxidant capacity of the organic-free-radical scavengers to 1.1-diphenyl-2-picrylhydrazyl (DPPH·) reagent in the leaf extracts of the seedlings and young trees of four woody species (Schima superba Gardn. et Champ., Castanopsis fissa (Champ. ex Benth.) Rehd. et Wils., Psychotria rubra (Lour.) Poir., Ardisia quinquegona Bl.) in exposureto different light intensities was investigated. The organic free radical scavenging capacity (ORSC) expressed as the percentage of decreasing DPPH· was 16%-59% (pot seedlings) or 48%-88% (young trees in the forest). The highest ORSC was observed in plants grown under natural light, and the ORSC reduced with the decreasing light intensity. Similar trend was observed through the assay of inhibition to linoleic acid oxidation. The ORSC of P. rufra, an understory shrub, was more sensitive to the change of light intensity. A linear relationship was found between ORSC and AsA (ascorbic acid) content (r=0.92) or the absorption around the wavelength of 204-227 nm. It is proposed that ORSC of leaf was regulated by incident light intensity, and the contents of AsA and, flavonoid phenolics might be the important components contributed to ORSC and total antioxidant activity of leaves. The increasing ORSC is likely to be a protective strategy of plant in response to strong light.     

3.2%高效氯氰菊酯·甲氨基阿维菌素苯甲酸盐微乳剂对十字花科蔬菜主要害虫的控制作用

田间药效试验结果表明,3.2%高效氯氰菊酯·甲氨基阿维菌素苯甲酸盐微乳剂对十字花科蔬菜主要害虫甜菜夜蛾Spodoptera exigua(Hbner)、小菜蛾Plutella xylostella(L.)、菜青虫Pieris rapae(L.)和斜纹夜蛾Spodoptera litura(Fabricius)均具有优良的防治效果,并有较好的速效性和持效性。3.2%高效氯氰菊酯.甲氨基阿维菌素苯甲酸盐微乳剂20,25和30g/667m23个处理药后1d对甜菜夜蛾、小菜蛾、菜青虫和斜纹夜蛾的防治效果为60.67%～77.41%,药后3d的防治效果达81.82%～97.77%,药后7d的防治效果达83.74%～99.25%。3.2%高效氯氰菊酯.甲氨基阿维菌素苯甲酸盐微乳剂可以作为防治蔬菜主要害虫的有效药剂推广使用,推荐使用剂量为25～30g/667m2(12～14.4gai/hm2)。     

45%烯肟菌胺·苯醚甲环唑·噻虫嗪种衣剂对麦田宽背金针虫和麦秆蝇的防治效果

采用田间试验评价的方法研究了45%烯肟菌胺·苯醚甲环唑·噻虫种衣剂对麦田宽背金针虫Selatosomus latus F.和麦秆蝇Meromyza saltatrix L.的防治效果。结果表明,该药剂对麦田宽背金针虫、麦秆蝇的防虫效果分别为71.43%-86.27%、55.35%-74.65%,以每10 kg种子80 g药剂处理防效最好;处理区小麦产量明显增加,增产率最高为15.87%。该三元复合种衣剂在防治小麦病虫害中具大面积应用的前景。     

DNA甲基化介导的植物逆境应答和胁迫记忆

DNA甲基化是表观遗传修饰的重要形式,它不仅对植物生长发育具有重要的调控作用,而且参与了植物对各种逆境胁迫的应答过程。逆境通过改变植物DNA基化水平和模式对胁迫应答基因网络进行调控,从而增强当代或后代对逆境的适应性。本文主要对DNA甲基化介导的生物和非生物逆境应答及植物胁迫记忆的最新研究进展进行综述,同时对该领域研究中存在的问题和未来研究的方向进行讨论与展望。     

Role of the tail in the regulated state of myosin 2

Myosin 2 from vertebrate smooth muscle or non-muscle sources is in equilibrium between compact, inactive monomers and thick filaments under physiological conditions. In the inactive monomer, the two heads pack compactly together, and the long tail is folded into three closely packed segments that are associated chiefly with one of the heads. The molecular basis of the folding of the tail remains unexplained. By using electron microscopy, we show that compact monomers of smooth muscle myosin 2 have the same structure in both the native state and following specific, intramolecular photo-cross-linking between Cys109 of the regulatory light chain (RLC) and segment 3 of the tail. Nonspecific cross-linking between lysine residues of the folded monomer by glutaraldehyde also does not perturb the compact conformation and stabilizes it against unfolding at high ionic strength. Sequence comparisons across phyla and myosin 2 isoforms suggest that the folding of the tail is stabilized by ionic interactions between the positively charged N-terminal sequence of the RLC and a negatively charged region near the start of tail segment 3 and that phosphorylation of the RLC could perturb these interactions. Our results support the view that interactions between the heads and the distal tail perform a critical role in regulating activity of myosin 2 molecules through stabilizing the compact monomer conformation.     

瓦宁木层孔菌中多酚和黄酮类成分分离及清除自由基活性的研究

采用硅胶和反相C18柱层析方法,首次从瓦宁木层孔菌中分离得到了5个化合物,运用NMR波谱法分析和鉴定为樱花亭、7-甲氧基二氢莰非素、二氢莰非素、4-(3,4-二羟苯基)-3-丁烯-2-酮、hispolon。并通过建立体外二苯基苦味酰基苯肼自由基（·DPPH）、超氧阴离子自由基（·O2?）以及羟自由基（·OH）发生体系,研究了5个化合物对·DPPH、·OH和·O2?的清除作用。结果表明当浓度达到100μg/mL时,化合物4-(3,4-二羟苯基)-3-丁烯-2-酮和hispolon对·DPPH清除率分别为92%和93%,对·OH的清除率分别为90%和95%,而对·O2?的清除率分别为70%和77%,略低于清除·DPPH和·OH的能力;二氢莰非素对·O2?自由基的清除率为39%,强于清除·OH和·DPPH的能力;而樱花亭和7-甲氧基二氢莰非素对3种自由基的清除率均低于30%。2个多酚类化合物清除自由基的能力均强于3个黄酮类化合物。5个化合物清除自由基能力均表现出一定的浓度依赖性。