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1.
The garlic-derived antibacterial principle, alk(en)yl sulfinate compounds, has long been considered as very short-lived substance. However, there are some data showing a rather more stable nature of allicin. We determined here the thermostability of allicin by a systematic analyses employing chemical quantification and an antibacterial activity assay. Allicin in an aqueous extract of garlic was degraded stoichiometrically in proportion to the temperature; we estimated the half-life of allicin to be about a year at 4 °C (from 1.8 mg/ml to 0.9 mg/ml) and 32 d at 15 °C, but only 1 d at 37 °C (from 2.0 mg/ml to 1.0 mg/ml). The half-life values for antibacterial activity showed a similar trend in results: 63 d or more at 4 °C for both antibacterial activities, 14 d for anti-staphylococcal activity, and 26 d for anti-escherichia activity at 15 °C, but only 1.2 d and 1.9 d for the respective activities at 37 °C. Such antibacterial activities were attributable to the major allicin, allyl 2-propenylthiosulfinate. Surprisingly, the decline in the quantity of allicin was not accompanied by its degradation; instead, allicin became a larger molecule, ajoene, which was 3-times larger than allicin.  相似文献   

2.
药用野生稻应答稻飞虱取食过程中基因表达的研究   总被引:1,自引:0,他引:1  
褐飞虱和白背飞虱是水稻的刺吸式害虫。为了探讨水稻对虫害反应的分子机理,采用cDNA—AFLP(互补DNA扩增片段长度多态性)技术,研究了药用野生稻受这两种飞虱取食后基因表达的变化。通过调查约7%的虫.崮答后的药用野生稻转录本组,共分离了258个差异片段,测序112个;44个片段对应于已知或假定功能基因,其中35个基因的表达水平在白背飞虱为害后发生改变,24个基因在褐飞虱为害后改变。下调的基因比上调的基因多。有14个基因受这两种飞虱共同调节(2个上调,12个下调)。结果表明,药用野生稻对两种飞虱为害作出的反应有所不同。  相似文献   

3.
4.
水稻品种和稻虱缨小蜂对褐飞虱协同作用的模拟分析   总被引:3,自引:0,他引:3  
利用我们先前的试验结果和文献资料,组建了水稻品种-褐飞虱-稻虱缨小蜂3者相互关系的模拟模型.模拟分析表明水稻品种能直接和间接地通过物理或化学特性影响稻虱缨小蜂的寄生作用,其中以影响褐飞虱卵垂直分布型、稻虱缨小蜂的迁入时间、未成熟期历期和怀印量等的水稻品种特性起主要作用.同时,模拟分析还表明中等抗性的水稻品种,配以增强稻虱缨小蜂寄生作用的品种特性,就能有效地控制褐飞虱的危害.文中还就协调水稻品种抗性与天敌协同控制褐飞虱的途径进行了讨论.  相似文献   

5.
褐飞虱迁飞参数的数值模拟   总被引:4,自引:0,他引:4  
包云轩  翟保平  程遐年 《生态学报》2005,25(5):1107-1114
迁飞性害虫褐飞虱对中国和亚洲其它国家和地区的水稻有着十分严重的危害,其迁飞参数的时空变化是种群迁飞这一生态行为的重要体现。应用目前国际上先进的中尺度数值预报模式MM5 (V3.2 )对我国褐飞虱北迁、南返的过程进行了数值模拟,根据模拟结果对害虫的迁出虫源地、迁飞路径、降落区、空中迁飞速率、迁飞高度、迁飞历时和迁飞距离等迁飞参数进行了一系列的数值计算和客观分析,得到了与实际虫情普查和雷达观测资料相当吻合的结果,从而比较精确地阐明了褐飞虱迁出起飞、空中定向飞行、降落迁入等迁飞行为的动力学机制。  相似文献   

6.
Studies on hybridization, inheritance, and population genetics of brown planthoppers that infest rice and weeds were undertaken using starch gel electrophoresis to determine whether the weed-infesting population represents a biological race or a species. F1 and F2 generations were produced by crosses between parental insects from the two populations with little indication of hybrid sterility. Gpi, Mdh, and Idh loci were inherited in a simple Mendelian fashion in families of two sympatric populations. Sixteen populations of Nilaparvata spp. from eight locations were collected. The Mdh, Idh, Pgm, Gpi, 6Pgd, and Acp loci were polymorphic. The N. lugens of rice with high esterase activity were clustered into a group and characterized by the presence of alleles Gpi 110 and Gpi 120 , whereas N. lugens from weeds with low esterase activity were clustered into another group and characterized by Gpi 100 and Gpi 90 . There was a lack of heterozygotes between the common alleles of the two populations. This means that the two groups of individuals belong to different gene pools.  相似文献   

7.
我国北方稻区1991年稻飞虱大发生虫源形成   总被引:9,自引:3,他引:9  
北方稻区在一般年份只有少量稻飞虱(褐飞虱Nilaparvata lugens,白背飞虱Sogatella fercifera)迁入,而与虫源区相隔千余公里的沿渤海湾稻区却在1991年稻飞虱暴发成灾,通过分析1991年各地稻飞虱主要迁入峰期的天气学背景和低空急流的时空分布及我国东部稻作区各地虫源的对应关系,表明大尺度低空急流的时空动态与南方(江岭区)大发生虫源的迁出期(区)相吻合的程度及维持时间乃北方稻虱大发生虫源得以形成的关键因子和暴发成灾的触发机制,其北上前缘左侧的暴雨区即远迁种群的集中降虫区,是否存在与南方大发生虫源时空同步且贯通南北的大尺度低空急流及其前缘的暴雨区可作为北方稻虱暴发的预警指标。  相似文献   

8.
The mermithid Agamermis unka, a parasite of the brown planthopper (BPH), was found in many rice paddies in Gyeongnam Province, Korea. Nematode parasitism of adult BPH varied from year to year, reaching as high as 50% in paddies not treated with an insecticide. Parasitism was lower in insecticide-treated paddies. Generally, mermithid parasitism was higher in BPH adults collected from the lower part (19%) compared with adults collected from the upper part (8%) of the rice plant and in brachypterous (57%) compared with macropterous forms (8%). No difference in parasitism between first (54%) and second (57%) generation was observed.  相似文献   

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10.
Populations of Nilaparvata lugens from 18 geographically defined and widely distributed regions in Asia and Australasia were maintained in the laboratory on growing rice plants. Crosses between some of these showed varying degrees of success in hybridization. Those between insects from Australia and the Solomon Islands had the lowest success rates, but in successful individual crosses there was little evidence of hybrid inviability. Behavioural barriers in the form of substrate transmitted courtship signals appeared to be primarily responsible for low success in hybridization. Pulse repetition frequencies of male calls were distinctive for different populations: those from Australia and the Solomon Islands showed the greatest difference. Divergence in mate recognition signals (pre-mating ethological isolating mechanisms) has apparently evolved in advance of general genetic incompatibilities (post-mating isolating mechanisms) in this species.  相似文献   

11.
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Highlights
  • •Nonenzymatically Ksu proteins shown different pattern from native cell Ksu proteins.
  • •Motif preference of Ksu proteins was associated with different biological processes.
  • •Up to 67 developing rice seeds proteins contain PTMs of Kac, Ksu, Kcr, Kmal, and Khib.
  • •Some lysine residues of the key pathway enzymes are modified by succinylation.
  相似文献   

12.
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Highlights
  • •Proteomic analysis of brain and cerebrospinal fluid from mouse NCL models.
  • •Disease-associated changes in lysosomal proteins and markers of neuroinflammation.
  • •Biomarker candidates identified for further evaluation.
  相似文献   

13.
Lethal control is used extensively in New Zealand to control nonnative nonhuman mammals. Respondents were surveyed about 8 mammal groups considered pests and their attitudes toward their control and pest status. They also identified the most appropriate method of control for the 8 different mammals. Information was gathered from 3 groups of respondents: nonhuman animal protectionists, conservationists, and the general public. Conservationists routinely rated all animal groups as more severe pests than the general public or animal protectionists, who provided the lowest scores. Rats, stoats, brushtail possums, and rabbits were identified as the 4 most serious pests by all 3 groups. Conservationists were 5.7 and 2.6 times more likely to prefer a lethal method of control than protectionists and the general public, respectively. For all 3 groups an increase in pest score for a given animal saw a decline in importance placed upon the animal's welfare. This relationship was strong for the general public but weak for conservationists and animal protectionists. Understanding aspects of potentially opposing viewpoints may be invaluable in supporting the development of new welfare-focused control methods.  相似文献   

14.
李迎春  钟杨生  林健荣 《昆虫学报》2015,58(11):1160-1166
【目的】分析家蚕Bombyx mori受饥饿胁迫后的蛋白质谱变化,探索其耐受饥饿的机理。【方法】以家蚕品种932为实验材料,利用双向电泳和质谱技术检测5龄起蚕经过24 h饥饿胁迫的蛋白质谱差异变化,利用荧光定量PCR技术分析BmLp-c 6的转录表达。【结果】经比对饥饿蚕和正常取食蚕的血淋巴蛋白谱,饥饿蚕有62个特异蛋白点。蛋白点的等电点在4.22~6.98之间,分子量分布在20.81~144.69 kDa间。选取只在饥饿时出现的特异蛋白点No. 7111进行质谱鉴定,根据其氨基酸序列进行引物设计,获得了目的基因BmLp-c 6,经与载体pET-21d(+)连接重组后,成功获得诱导表达。经实时荧光定量PCR分析,当5龄起蚕受到饥饿胁迫影响时,BmLp-c 6基因在血淋巴中大量转录表达,但在中肠中的转录表达水平却极低。【结论】家蚕5龄起蚕在饥饿胁迫下,血淋巴中的蛋白质谱发生变化,BmLp-c 6会大量转录表达。  相似文献   

15.
The ADE1 gene from Candida utilis CA(u)-37, a strain used for commercially producing enzymes, was cloned by complementation of the ade1 mutation of Saccharomyces cerevisiae. It was composed of 903 bp, and the deduced amino acid sequence was 70% homologous to those of the ADE1 genes of S. cerevisiae and Candida maltosa. The highly preserved region of SAICAR synthetase, the ADE1 gene product, was also found by a homology search.  相似文献   

16.
The biogenesis of peroxisomes is mediated by peroxins (PEXs). PEX7 is a cytosolic receptor that imports peroxisomal targeting signal type 2 (PTS2)-containing proteins. Although PEX7 is important for protein transport, the mechanisms that mediate its function are unknown. In this study, we performed proteomic analysis to identify PEX7-binding proteins using transgenic Arabidopsis expressing green fluorescent protein (GFP)-tagged PEX7. Our analysis identified RabE1c, a small GTPase, as a PEX7 binding partner. In vivo analysis revealed that GTP-bound RabE1c binds to PEX7 and that a subset of RabE1c localizes to peroxisomes and interacts with PEX7 on the peroxisome membrane. Unlike endogenous PEX7, which is predominantly localized to the cytosol, GFP-PEX7 accumulates abnormally on the peroxisomal membrane and induces degradation of endogenous PEX7, concomitant with a reduction in import of PTS2-containing proteins and decreased peroxisomal β-oxidation activity. Thus, GFP-PEX7 on the peroxisomal membrane exerts a dominant negative effect. Mutation of RabE1c restored endogenous PEX7 protein expression and import of PTS2-containing proteins as well as peroxisomal β-oxidation activity. Treatment with proteasome inhibitors also restored endogenous PEX7 protein levels in GFP-PEX7-expressing seedlings. Based on these findings, we conclude that RabE1c binds PEX7 and facilitates PEX7 degradation in the presence of immobile GFP-PEX7 accumulated at the membrane.  相似文献   

17.
根据日本晴cab4基因序列(GenBank:AK104499.1)设计引物,用RT-PCR的方法从籼稻9311中克隆了叶绿素a/b结合蛋白基因的全长cDNA,命名为cab-9311(cab gene from 9311)。insilico分析表明:cab-9311与cab4基因同源性为99%,编码的蛋白含有244个氨基酸,与cab4基因编码的蛋白同源性为98%。蛋白分子质量为26.9kD,理论等电点为6.52。第54位~第216位氨基酸是一个典型的叶绿素a/b结合蛋白功能域(chlorophyll a/bbinding domain)。跨膜分析和蛋白质三级预测显示,该蛋白在C端有一个典型的跨膜区。亚细胞定位分析表明该蛋白定位于叶绿体,是一个叶绿体内囊体膜上的锚定蛋白。  相似文献   

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