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1.
植物中存在天然的转录后基因沉默机制来消除病毒对其的危害,而病毒也进化出不同的对策来逃避甚至消除这种抑制机制;目前研究发现黄瓜花叶病毒(CMV)的2b蛋白及马铃薯丫病毒(PVY)的HC蛋白等植物病毒蛋白能抑制植物转录后基因沉默,对它们相应的抑制机理已了解。研究转录后基因沉默抑制蛋白不仅有助于阐明RNA沉默的具体过程,也为未来的转录后基因沉默甚至RNAi的调控提供研究工具和思路。 相似文献
2.
CMV甜瓜分离物外壳蛋白基因的克隆及其生物信息学分析 总被引：1，自引：0，他引：1
马新艳 《南阳师范学院学报》2008,7(12)
从河南省临颖县采集的病毒感染的甜瓜样本经ELISA检测和接种分离获得黄瓜花叶病毒（Cucumber mosaic vi-rus,CMV）分离物。把该分离物接种于西葫芦,从发病的叶片中提取总RNA,并以此为模板经RT-PCR扩增获得CMV的外壳蛋白（cp）基因,将其克隆到pUCm-T质粒上。经序列测定和生物信息学分析,结果表明该cp基因由657个核苷酸组成,编码218个氨基酸。预测该蛋白的等电点为5。12,分子量约为24kD。其核苷酸序列与黄瓜花叶病毒亚组I的分离物有较高的同源性,达92.2%～93.9%,与亚组II的同源性仅为76.8%～77.8%,与我国报道的CMV分离物的cp基因序列比较,只有香蕉株系XB外核苷酸序列的同源性达91.8%～93.4%。根据这些分析,该CMV分离物属于亚组I。另外还对黄瓜花叶病毒外壳蛋白的高级结构作出了预测。 相似文献
3.
曹丽 《华夏少年(简快作文 )》2010,(1)
中心法则是指遗传信息从DNA传递给RNA,再从RNA传递给蛋白质的转录和翻译的过程,以及遗传信息从DNA传递给DNA的复制过程。这是所有有细胞结构的生物所遵循的法则。在某些病毒中的RNA自我复制(如烟草花叶病毒等)和在某些病毒中能以RNA为模板逆转录成DNA的过程(某些致癌病毒)是对中 相似文献
4.
在生物学上曾认为传染性疾病的传播源必定要具有遗传物质——核酸（DNA、RNA）才会使寄主感染致病,就如病毒这样最简单的生命形式也是依靠将自己的核酸整合到寄主细胞的DNA上并复制自己的DNA（RNA）和蛋白质来进行增殖的。但在20世纪随着医学科学的发展和对一些特殊病例的研究,发现了一些特殊蛋白质（也有一些正常的蛋白质经诱导变形后）也会成为疾病的传染源。 相似文献
5.
石菊花 《中学生数理化(高中版)》2008,(Z1)
一、知识归纳(1)病毒(如噬菌体)是没有细胞结构、由蛋白质和核酸(每种病毒只含一种核酸,如DNA或RNA)等物质组成的简单生命体,营寄生生活,以复制的方式增殖.离开寄主无生命活性.不要把它们当成原核生物. 相似文献
6.
感染新疆甜瓜的黄瓜花叶病毒的生物学特征 总被引：1，自引：0，他引：1
郑光宇 《喀什师范学院学报》2005,26(3):49-52
从新疆感染病毒病的甜瓜(Cucumis melo)分离到一株球形病毒．该病毒在人工接种条件下可经汁液传播侵染属于9科的24种草本植物；该病毒可经桃蚜以非持久性方式传播；染病组织粗汁液和提纯病毒制备物在SDS双向免疫扩散试验和酶联免疫吸附试验(ELISA)中与黄瓜花叶病毒抗血清发生强烈的免疫反应；该病毒的病毒粒子为直径28～30nm的球形病毒粒子；以差速离心和蔗糖密度梯度离心提纯了该病毒，纯化病毒的A260／A280为1．65；用提纯病毒制备了ELISA试验效价为1：10^7的抗血清；该病毒可经西瓜、甜瓜和西葫芦种子以较低的种子带病率传播．实验证明该株病毒应属于黄瓜花叶病毒(Cucumber mosaic virus)的一个株系，建议将该株病毒称为黄瓜花叶病毒新疆株(Cucumber mosaic virus-Xinjiang，CMV-XJ)． 相似文献
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8.
石磬 《中学生数理化(高中版)》2002,(9)
病毒(virus)是一种狡猾的致病微生物,它单独存在时不生不长,而当它“钻入”寄主(parasit-ism)细胞,会被“激活”,不断繁殖,将寄主细胞置于死地。原来,病毒由两部分组成——蛋白质壳和壳内的RNA链,病毒会“识别”寄主细胞膜上的某些 相似文献
9.
朊病毒是一种裸露的、小分子量、有侵染性的RNA或蛋白质分子。人和哺乳动物的多种神经系统疾病与朊病毒有关。牛海绵状脑病(Bovin spongiform encephalopathy,BSE)病毒与目前在英国发现的一种新型的人防病毒(vCJDV),是同一种病毒。 相似文献
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11.
INTRODUCTIONCucumbermosaicvirus (CMV) ,thetypespeciesofthegenusCucumovirusoffamilyBro moviridae,isanisometricviruswithatripartitesingle strandedRNAgenomeofpositivepolari ty.CMVhasaparticularlywidehostrange ,in fectingmorethan 80 0speciesinover 70familieso… 相似文献
12.
The cucumber mosaic virus (CMV) isolate P1 caused very mild symptoms on many plant species After serial passages by mechanical
inoculation over five years, CMV P1 caused severe symptoms on several tobacco cultivars and tomato. A specific band of approximately
0.3 kb in length was amplified by RT-PCR with primers synthesized based on reported CMV satellite RNA (satRNA) sequences.
Sequence analysis showed there were two satRNAs (Sat-P1-1 and Sat-P1-2). Sat-P1-1 contained 335 nucleotides, and Sat-P1-2
contained 394 nucleotides. These two satRNAs shared 64% overall nucleotide sequence homology, and differences between the
two satRNAs included mutations as well as deletions. Sat-P1-1 was identical to a satRNA (Z96099) reported in 1995 in CMV P1.
Based on differences in the sequence and secondary structure between these two satRNAs, we conclude that Sat-P1-2 represents
the emergence of a new satellite (necrotic satellite) from attenuated satRNA populations. The possible effect of the emergence
of this new satRNA is discussed.
Project supported by research grants from the Teaching and Research Award Program for Outstanding Teachers in Higher Education
Institutes of the Ministry of Education of China and by the National Outstanding Youth Foundations of National Natural Science
Foundation of China (No. 30125032).
PhD student in Zhejiang University, from Agrarian University of Havana, Cuba. 相似文献
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14.
通过对烟蚜茧蜂防治烟蚜的试验表明,在初始蚜量较低的条件下,采用3次以上放蜂的方法散放烟蚜茧蜂防治烟蚜,可有效地缓解烟蚜种群数量的增长,相当于施用化学杀蚜剂的防治效果.但繁殖烟蚜茧蜂所依赖的烟蚜,给烟叶生产中黄瓜花叶病（CMV）、马铃薯Y病毒病（PVY）、烟草丛顶病（TBTV）等烟草病毒病的发生与流行带来潜在风险.为此,在强调加大力度规范烟蚜茧蜂的繁殖与散放操作的同时,还需要进一步研究更为经济有效的综合防治措施. 相似文献
15.
The AtTOM1 gene of Arabidopsis thaliana had been shown to be essential for the efficient multiplication of Tobacco mosaic virus(TMV) in A.thaliana.In this study,we cloned an AtTOM1-like gene from Nicotiana benthamiana named as NbTOM1.Sequence alignment showed that NbTOM1 is closely related to AtTOM1 homologues of N.tabacum and Lycopersicon esculentum with 97.2% and 92.6% nucleotide sequence identities,respectively.Silencing of NbTOM1 by a modified viral satellite DNA-based vector resulted in complete inhibition of the multiplication of TMV in N.benthamiana.The result suggests that inhibition of NbTOM1 via RNA silencing is a potentially useful method for generating TMV-resistant plants. 相似文献
16.
ＩＮＴＲＯＤＵＣＴＩＯＮＢｒｏａｄｂｅａｎｗｉｌｔｖｉｒｕｓ (ＢＢＷＶ)ｉｓｔｈｅｔｙｐｅｍｅｍｂｅｒｏｆｔｈｅｇｅｎｕｓＦａｂａｖｉｒｕｓ.Ｉｔｈａｓａｗｉｄｅｈｏｓｔｒａｎｇｅａｍｏｎｇｄｉｃｏｔｙｌｅｄｏｎｓａｎｄｓｏｍｅｆａｍｉｌｉｅｓｏｆｍｏｎｏｃｏｔｙｌｅｄｏｎｓ,ａｎｄｉｓａｎｅｃｏｎｏｍｉｃａｌｌｙｉｍ ｐｏｒｔａｎｔｖｉｒｕｓｉｎＣｈｉｎａ (Ｚｈｏｕｅｔａｌ.,1 994 ) .ＢＢＷＶｈａｓｉｓｏｍｅｔｒｉｃｐａｒｔｉｃｌｅｓ,ｈｅｘａｇｏｎａｌｉｎｏｕｔ ｌｉｎｅａｎｄ 3 0ｎｍｉｎｄｉａｍ… 相似文献
17.
Lang QL Zhou XC Zhang XL Drabek R Zuo ZX Ren YL Li TB Chen JS Gao XL 《Journal of Zhejiang University. Science. B》2011,12(2):116-125
A large number of plant microRNAs (miRNAs) are now documented in the miRBase, among which only 30 are for Solanum lycopersicum (tomato). Clearly, there is a far-reaching need to identify and profile the expression of miRNAs in this important crop under
various physiological and pathological conditions. In this study, we used an in situ synthesized custom microarray of plant
miRNAs to examine the expression and temporal presence of miRNAs in the leaves of tomato plants infected with Cucumber mosaic virus (CMV). Following computational sequence homology search and hairpin structure prediction, we identified three novel tomato
miRNA precursor genes. Our results also show that, in accordance with the phenotype of the developing leaves, the tomato miRNAs
are differentially expressed at different stages of plant development and that CMV infection can induce or suppress the expression
of miRNAs as well as up-regulate some star miRNAs (miRNA*s) which are normally present at much lower levels. The results indicate
that developmental anomalies elicited by virus infection may be caused by more complex biological processes. 相似文献
18.
Broad bean wilt virus 2 (BBWV2) isolate P158 was characterized and the complete nucleotide sequence of viral genomic RNA2
was determined. P158 has 30 nm diameter isometric particles. Double immunodiffusion test suggested that P158 has high antigenicity
homology with BBWV2 isolate B935. SDS-PAGE result showed that the coat protein of P158 was comprised of two types of polypeptide
with molecular weight of 44.7 kD and 21.9 kD, respectively. The genome of P158 was made up of two RNA molecules with the length
of 6.0 kb and 3.6 kb, respectively. cDNA of RNA2 was cloned by RT-PCR and sequenced. RNA2 was composed of 3597 nucleotide
(nt) residues excluding the poly(A) tail and contained single long open reading frame extending from nt 230 to nt 3424 in
the viral sense RNA, and encoded a polyprotein ofMr 119002 (119K). Comparison of the polyprotein and the counterpart of isolate B935 indicated that the polyprotein was cleaved
at Q/G (465/466) and Q/A (867/868), to release three mature proteins: a protein of unknown function, large and small subunit.
Sequence comparisons of P158 with fabaviruses showed P158 had very high sequence homology with BBWV2 isolates and patchouli
mild mosaic virus, but to a less extent with BBWV1 isolates.
Project supported by NSFC (No 39770035; 39900005). The GenBank accession number of the sequence reported in this paper is
AF228423. 相似文献
19.
任金梅 《山西广播电视大学学报》2006,11(1):41-42
目前计算机病毒可以渗透到信息社会的各个领域,给计算机系统带来了巨大的破坏和潜在的威胁。为了确保信息的安全与畅通,研究计算机病毒的防范措施已迫在眉睫。首先从计算机病毒的类型、特点入手,初步探讨对付计算机病毒的方法和措施。并举例阐述了清除病毒的方法。 相似文献
20.
闽东太子参花叶病发病规律调查及防治途径研究 总被引：2，自引：0，他引：2
太子参以种根无性繁殖，病毒病逐年加重，闽东太子参花叶病发病面积占总栽培面积的30％-40％，大部分种植区发病率达60％-90％，平均产量损失达28．2％。经鉴定，闽东太子参花叶病病原为黄瓜花叶病毒CMV，可通过种根无性繁殖传至下一代，也可通过土壤和蚜虫传染给健株．经试验，提出了以茎尖脱毒苗为主，进行土壤消毒、切断传播途径的综合防治措施． 相似文献