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1.
本研究以马铃薯Y病毒(PVY)全基因组为基础,分析吉林、黑龙江和内蒙古3省(区)PVY群体遗传多样性和群体分化,并评估突变、重组、选择等遗传力所起的作用。根据已报道的PVY全基因序列保守区设计4对引物,采用片段重叠法对来自内蒙古和吉林的24个PVY分离物全基因序列进行测定,并联合NCBI中已登录的9个黑龙江分离物全基因组序列进行遗传多样性参数评估、群体分化检验和分子变异等分析。结果显示,我国北方3省(区)PVY群体遗传多样性高,其中内蒙古和黑龙江PVY群体遗传多样性高于吉林群体,并且3个群体之间呈现一定程度的遗传分化。分子变异分析发现在PVY基因组中存在1 786个变异位点,表明我国北方3省(区)PVY群体变异程度较高,并且这种高变异度有85.54%来自各个马铃薯种植区内PVY个体的遗传变异。重组分析和系统发育分析发现,我国北方3省(区)PVY群体中重组株系占比高达90.3%,并具有明显的株系多样性,表明PVY重组株系已成为我国北方3省(区)马铃薯种植区的流行株系。选择压力分析显示,使用FEL和IFEL法分别检测出501个和315个净化压力选择位点,这表明3省(区)PVY群体受净化选择压力为主。以上结果表明,中国北方3省(区)PVY群体遗传多样性高,突变、重组和自然选择都对遗传多样性和群体分化存在一定影响。 相似文献
2.
马铃薯Y病毒(potato virus Y,PVY)主要侵染马铃薯和烟草等茄科作物,给世界农业造成巨大经济损失。本文对测定的23个及GenBank中注册的52个中国PVY分离物ORF序列进行了系统发育、重组和选择压等分析。系统发育分析表明,根据ORF序列可把我国75个PVY分离物和国外30个参比分离物分成O、C、E、NTN-NW(SYR-I型)、NTN-NW(SYR-II型)、NTN(NTN-a型)、NTN(NTN-b型)、NA-N/NTN、Eu-N、N-Wi(N:O型)和N-Wi(N-Wi型)等11个分子株系,其中中国PVY分离物属于除E和C株系外的9个分子株系。除ME162、guiyang、PVYzu、SD-G、WA-13和CN:JL-1:17等 6个分离物基因组中未检测到重组,其余69个分离物均存在明显重组。根据重组位点的不同,中国PVY可分为11种重组类型,其中5种为新的重组类型。选择压分析表明,中国PVY分离物的11个基因均处于负选择,其中核内含体b基因受到的选择压最大,PIPO受到的选择压最小。基因流分析表明,黑龙江、河南和山东PVY分离物间基因交流频繁,马铃薯与烟草PVY分离物之间基因交流频繁。本研究的结果明确了中国PVY分离物的分子株系组成,对指导PVY的检测和防控具有积极作用。 相似文献
3.
马铃薯是我国重要粮食和经济作物。马铃薯Y病毒(potato virus Y,PVY)是危害马铃薯生产的重要病害。种植脱毒种薯是防治PVY最有效的途径。马铃薯种薯携带PVY问题严重,但种薯中PVY株系还不清楚。本研究利用PVY特异性抗体检测了7个马铃薯品种362个种薯,发现不同品种种薯带毒率差异较大,最高达12%。通过RT-PCR方法扩增获得了7个PVY分离物编码区全序列。重组分析发现7个分离物基因组均为重组型,根据重组位点的差异可以分为PVYNTN-NW(SYR-II型)、Rec-1、Rec-2和Rec-3等4种重组类型,后3种为新重组类型。系统进化分析发现,分离物HQH18G3-10与PVYNTN-NW(SYR-II型)处于同一个大的分支,但与中国PVY大田分离物聚集在一起形成一个相对独立的组,命名为PVYNTN-NW(CN型);其余6个分离物与数据库中的中国分离物聚集在PVYN-Wi组。这暗示PVY中国分离物具有相对独立的进化过程,PVY马铃薯大田分离物和种薯分离物进化上相近。所有分离物均能在珊西烟上引起典型叶脉坏死症状,HQH18G3-10引起的坏死症状最为严重。本研究首次报道了我国种薯内PVY发生情况,对分析病毒发生发展规律和防控具有借鉴作用。 相似文献
4.
马铃薯是我国重要粮食和经济作物。马铃薯Y病毒(potato virus Y,PVY)是危害马铃薯生产的重要病害。种植脱毒种薯是防治PVY最有效的途径。马铃薯种薯携带PVY问题严重,但种薯中PVY株系还不清楚。本研究利用PVY特异性抗体检测了7个马铃薯品种362个种薯,发现不同品种种薯带毒率差异较大,最高达12%。通过RT-PCR方法扩增获得了7个PVY分离物编码区全序列。重组分析发现7个分离物基因组均为重组型,根据重组位点的差异可以分为PVYNTN-NW(SYR-II型)、Rec-1、Rec-2和Rec-3等4种重组类型,后3种为新重组类型。系统进化分析发现,分离物HQH18G3-10与PVYNTN-NW(SYR-II型)处于同一个大的分支,但与中国PVY大田分离物聚集在一起形成一个相对独立的组,命名为PVYNTN-NW(CN型);其余6个分离物与数据库中的中国分离物聚集在PVYN-Wi组。这暗示PVY中国分离物具有相对独立的进化过程,PVY马铃薯大田分离物和种薯分离物进化上相近。所有分离物均能在珊西烟上引起典型叶脉坏死症状,HQH18G3-10引起的坏死症状最为严重。本研究首次报道了我国种薯内PVY发生情况,对分析病毒发生发展规律和防控具有借鉴作用。 相似文献
5.
采用单链构象多态性分析从建兰花叶病毒(Cymbidium mosaic virus,CyMV)的8个分离物筛选得到5个存在遗传变异的分离物,并测定了外壳蛋白(coat protein,CP)基因和3'非编码区(3'UTR)序列,经序列分析表明5个分离物与其他分离物间的CP核苷酸和氨基酸序列相似性分别为87,1％～99.9％和91.1％～99.6％,属于亚组A成员.CP基因不同片段受到正选择压力的作用不一样,C端受到负选择压力的作用不易发生变异,而N端受到正选择压力的作用容易发生变异.通过RNAsharpes软件分析3 'UTR序列发现各分离物均形成带有Potexvirus属保守核苷酸序列“AC(C/T) TAA”的三叶草茎环结构,这种结构的功能可能与病毒RNA复制有关. 相似文献
6.
为明确侵染白附子的芋花叶病毒(dasheen mosaic virus,DsMV)的分子变异情况,对51个DsMV白附子分离物(DsMV-BF)的外壳蛋白(Coat Protein,CP)基因和3个分离物的近全长基因组序列进行了克隆和测定,DsMV-BF的CP基因大小有855个和942个核苷酸两种类型,51个白附子分离物之间CP基因的核苷酸和氨基酸一致率分别为88.3%~100%和91.9%~100%,BF8、BF30和BF38分离物之间多聚蛋白的核苷酸和氨基酸序列一致率分别为82.9%~95.9%和90.7%~95.9%,与GenBank中其他分离物之间多聚蛋白的核苷酸和氨基酸序列一致率分别为76.9%~99.4%和85.6%~99.0%;P1基因的分子变异较大,P1基因大小有987个和990 个核苷酸两种类型;CP基因核苷酸序列系统进化树分析结果表明,侵染白附子的DsMV分离物可分为两个亚组;重组分析结果表明BF8和BF30分离物各检测到1个重组事件,BF38检测到2个重组事件。 相似文献
8.
马铃薯Y病毒 (potato virus Y,PVY) 是一种重要的农作物病毒,可造成产量损失和产品质量下降。其宿主范围广泛,包括马铃薯、烟草、番茄和辣椒等经济作物。在广西从叶片表现斑驳褪绿症状的马铃薯上分离到一株PVY分离物DX,其基因组包含一个大的开放阅读框 (open reading frame,ORF),由9 186 nt组成,编码3 061个氨基酸。系统发育进化分析显示,分离物DX与PVYN-Wi株系分离物IUNG-12、SGS-AG、MAF-VOY聚类成一个分支。重组分析表明分离物DX基因组在496 nt和2 388 nt存在重组位点,分别位于P1和HC-Pro/P3结合区,是分离物Oz和N605的重组体。通过机械摩擦接种,分离物DX可侵染茄科9种作物,引起本生烟叶片花叶、皱缩和泡状突起等症状;引起普通烟草和番茄的轻微花叶症状;引起马铃薯叶片花叶症状,接种辣椒没有发病。序列比对分析显示,分离物DX缺乏引起烟草叶脉坏死相关的氨基酸位点N205、K400和E419。本研究比较了分离物DX对茄科共12种作物的侵染能力和病害症状差异,结果表明分离物DX可用于探索PVY在不同寄主中的致病机理。 相似文献
9.
通过RT-PCR扩增了黄瓜绿斑驳花叶病毒(Cucumber green mottle mosaic virus,CGMMV)济南分离物(CGMMV-JN)的基因组片段。序列测定结果表明CGMMV-JN基因组全长6 424核苷酸(nt),5′-和3′-UTR分别为60和176 nt,含有4个ORF,分别编码129 kDa和186 kDa复制酶相关蛋白、29 kDa移动蛋白及17.4 kDa外壳蛋白。CGMMV-JN与另外29个CGMMV分离物全基因组核苷酸序列一致率为90.0%~99.7%。重组分析发现韩国KOM(AF417243)、以色列EC(KF155231)、印度(DQ767631)和我国河北的CHB(KJ658958)4个分离物在RdRp编码区存在重组。系统发育分析结果表明,这些分离物可分成3个组。选择压力分析结果表明cp基因处于正选择,其它基因处于负选择。本文研究的结果为黄瓜绿斑驳花叶病毒的监测及防控提供了理论依据。 相似文献
10.
为探明湖南烟草上发生的黄瓜花叶病毒Cucumber mosaic virus(CMV)的遗传多样性及分子进化特征,对来自湖南烟区的303份疑似感染病毒的烟草样品进行检测,分析CMV系统发育、遗传变异和群体结构等特征。结果表明：部分分离物的外壳蛋白(coat protein, CP)基因与NCBI上登录的CMV分离物的一致性为86.34%～98.42%;系统发育分析发现湖南烟草CMV分离物属ⅠB组,不同组间的分离物地理特征不明显,无重组现象,进化的主要驱动力是负选择;组间遗传变异比较明显,基因交流频率较低,受到遗传漂变影响,遗传多样性高,群体趋于扩张。研究结果为烟草抗CMV育种提供了理论依据,对病害防治具有重要意义。 相似文献
11.
Jian-Sheng Chen Shan-Shan Liang Sheng-Ren Sun Mona B. Damaj Hua-Ying Fu San-Ji Gao 《Plant pathology》2020,69(7):1390-1400
RNA silencing is one of the conserved antiviral mechanisms in plants, and viruses encode RNA silencing suppressors (RSS) to overcome host RNA silencing and facilitate virus infection. Sugarcane streak mosaic virus (SCSMV; species Sugarcane streak mosaic virus, genus Poacevirus, family Potyviridae) is a major causal agent of sugarcane mosaic disease in many countries in Asia, including China. In this study, we used Agrobacterium co-infiltration to show that the SCSMV P1 protein, rather than the helper component-proteinase (HC-Pro), functions as a strong RSS to suppress local RNA silencing in Nicotiana benthamiana. Mutational analysis indicated that the 15 amino acids (aa; aa 1–15) of the SCSMV P1 N-terminus were not important for RNA silencing suppression, but rather another 15 aa domain (aa 108–122) containing a conserved motif (LFR/KNKQAYIST) was essential for efficient silencing suppression by P1. In addition to the 15 aa (aa 344–358) domain in the P1 N-terminus, another 15 aa domain (aa 65–79) of P1, containing the LXKA motif and one conserved aa (D78), were associated with P1 protein stability. Furthermore, substituting the histidine (H263) residue in P1 with threonine (H263T) or alanine (H263A) also affected P1 protein stability. Notably, the H263 residue is both a positively selected site and part of the serine protease catalytic triad (HDS). Taken together, our data demonstrate that SCSMV P1, and not HC-Pro, plays a functional role in suppressing RNA silencing, and also show that some conserved motifs and a positivelyselected site in the P1 protein are associated with RSS activity and protein stability. 相似文献
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13.
基于全基因组编码区序列的烟草花叶病毒分子进化分析 总被引：1，自引：0，他引：1
为揭示烟草花叶病毒分子进化特征,从GenBank中下载已报道的烟草花叶病毒全基因组编码区序列,进行重组、系统发育、遗传变异、种群结构和基因漂流等分析。结果表明:突变和负选择作用是驱动烟草花叶病毒进化的主要作用力,种群结构稳定,处于扩张趋势中,基因变异程度低,重组在烟草花叶病毒分子进化中作用不明显。烟草花叶病毒不同分离物形成3个有一定地理相关性的种群ChinaⅠ、ChinaⅡ和Europe。欧洲分离物核苷酸序列多样性比中国的差异大,Europe和ChinaⅠ种群可能受到遗传漂变影响,Europe与ChinaⅡ、ChinaⅠ与ChinaⅡ之间存在发生基因交流的渠道。 相似文献
14.
Adnan Ahmad Muhammad Ashfaq 《European journal of plant pathology / European Foundation for Plant Pathology》2018,151(4):891-900
Chilli veinal mottle virus (ChiVMV), is a Potyvirus that causes severe yield losses in capsicum worldwide including Pakistan. In the current study, genetic diversity and molecular evolution of ChiVMV were explored based on the CP gene sequences. In multiple sequence alignments of the CP gene of 29 ChiVMV isolates, Pakistani isolates shared 82–92% and 78–96% nucleotide and amino acid identities, respectively with other ChiVMV isolates. In nucleotide and amino acid based phylogenetic analysis of the CP gene, the Pakistani isolates clustered with Indian (JN692501 and JN624776) and Chinese (KC711055, KC711055, JX088636 and HQ218936) isolates in a separate clade. In all Pakistani isolates, conserved motifs (DAG, WCIEN, QMKAAL, and AFDF) were located at 6–8, 141–145, 222–225, and 242-248th amino acid positions, respectively. Eleven recombination events were detected in the isolates investigated. One Pakistani isolate KX236451 was suggested to be a recombinant between the Pakistani isolate (KT876050) and the Indian isolate (JN692501). Most of the codons were found under negative selection except for codons at 28, 34, and 38th positions that were found under positive selection by REL method. An infrequent gene flow was observed between the ChiVMV isolates from Pakistan and other countries of the world. To our knowledge, this is the first report on genetic diversity of Pakistani isolates of ChiVMV based on recombination and phylogenetic analysis. Findings of this study may be helpful in developing sustainable management strategies against ChiVMV not only in Pakistan but also in other countries, ultimately resulting in enhanced and good quality production of chilli crop. 相似文献
15.
Chu-Hui Chiang Chun-Yee Lee Ching-Hsien Wang Fuh-Jyh Jan Shih-Shun Lin Tsung-Chi Chen Joseph A. J. Raja Shyi-Dong Yeh 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(4):333-348
Papaya ringspot virus (PRSV) HA 5-1, a nitrous acid-induced mild mutant of severe strain HA, widely applied for control of PRSV by cross-protection,
was used to study the genetic basis of attenuation. Using infectious clones, a series of recombinants was generated between
HA 5-1 and HA and their infectivity was analyzed on the systemic host papaya and the local lesion host Chenopodium quinoa. The recombinants that contained mutations in P1 and HC-Pro genes caused attenuated infection on papaya without conspicuous
symptoms, similar to HA 5-1. The recombination and sequence analyses strongly implicated two amino acid changes in the C-terminal
region of P1 and two in HC-Pro of HA 5-1 involved in the attenuated infection on papaya. The recombinants that infected C. quinoa plants without local lesions contained the same mutations in the C-terminal region of HC-Pro for attenuated infection on
papaya. We conclude that both P1 and HC-Pro bear important pathogenicity determinants for the infection on the systemic host
papaya and that the mutations in HC-Pro affecting pathogenicity on papaya are also responsible for the inability to induce
hypersensitive reaction on C. quinoa. 相似文献
16.
Positional effect of gene insertion on genetic stability of a clover yellow vein virus-based expression vector 总被引：4，自引：0，他引：4
The stability of the inserted genes in the viral expression vector varied depending on the sequence introduced and the position of insertion. Infectious cDNA to Clover yellow vein virus (pClYVV) was modified to insert a foreign gene at two independent sites: one, along with a polylinker, between the NIb and CP genes (pClYVV/CP/W) and the other between P1 and HC-Pro (pClYVV-Pst/CP). The green fluorescent protein (GFP) gene was inserted into either pClYVV/CP/W or pClYVV-Pst/CP. GFP gene was stably maintained and expressed in both vectors following serial passages in plants. Progeny viruses from both constructs accumulated in similar amounts and at rates of 70%–80% of that of the wild-type virus. On the other hand, progeny viruses carrying the human interferon- (hIFN) gene cloned in pClYVV-Pst/CP were genetically unstable owing to frequent deletions of the cloned gene during passage through plants. In contrast, the hIFN sequence cloned in pClYVV/CP/W was stably maintained in viruses after several passages in broad bean plants, and the progeny virus accumulated at the rate of about 50%–100% of that of the wild-type virus. The nucleotide sequence analyses indicated that the genetic instability of the inserted sequence results from homologous recombination of viral vector and inserted DNA sequences; it is not due to the inserted sequence alone. 相似文献
17.
18.
Wei-Qin Wang Tomohide Natsuaki Yoshitaka Kosaka Seiichi Okuda 《Journal of General Plant Pathology》2006,72(1):52-56
To identify possible sites of viral attenuation, the complete nucleotide sequences of two isolates of Zucchini yellow mosaic virus (ZYMV) were determined; a severe isolate Z5-1 and an attenuated isolate from Z5-1 (designated ZYMV-2002). The viral genome
of both isolates consisted of 9593 nucleotides in size and contained an open reading frame encoding a single polyprotein of
3080 amino acids. Comparison of the nucleotide sequences for Z5-1 and ZYMV-2002 revealed 14 nucleotide mutations, resulting
in seven amino acid substitutions with four in the HC-Pro region, two in the CI region, and one in the NIb region. These results
provide a genetic basis for future manipulation of the ZYMV reverse genetics system.
The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under the accession numbers AB188115
and AB188116 相似文献