First Report of a Distinct Begomovirus Infecting Cassava from Zanzibar.
First Report of a Distinct Begomovirus Infecting Cassava from Zanzibar.
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首次报道一种独特的 Begomovirus 感染桑给巴尔木薯。
DOI：
10.1094/pdis.2002.86.2.187a
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发表时间：
2002
期刊：
影响因子：
4.5
通讯作者：
J. Thresh
中科院分区：
文献类型：
--
作者：
M. Maruthi;J. Colvin;S. Seal;J. Thresh
1998年，从桑给巴尔的乌古贾岛采集了表现出极轻微花叶病症状的木薯植株。从症状叶片中提取的总DNA不能用已知的木薯花叶病毒(双生病毒科BegomVirus，Geminiviridae)的特异性引物产生诊断的PCR条带(2)。然而，简并引物A/B(1)在DNA-A的共同区产生了一条564个核苷酸(NT)的条带，该条带与秋病毒外壳蛋白基因内保守的氨基酸序列CEGPCKYG有关。设计病毒特异性引物，扩增并克隆病毒基因组，获得基因组全长DNA-A(2,785个核苷酸)(AF422174)和部分DNA-B(2,403个核苷酸)(AF422175)，包括BV1开放阅读框(ORF)的5‘端到共同区域的8(A)保守纳米核苷酸TAATTAC。系统进化分析表明，该病毒与东非木薯花叶病毒(EACMV)的亲缘关系最近，分别来自坦桑尼亚(Z83256，83%同源性)和乌干达(AF126805，87%同源性)。根据DNA-A和-B组分，其在非洲木薯花叶病毒分离物中的近亲分别是尼日利亚分离物(X17095，同源性为67%)和乌干达分离物(AF126800，同源性为38%)。病毒ORF的数量和排列与来自东半球的其他两部分秋病毒相同。目前正在进行工作，以确定这种巨型病毒是现有EACMV的新毒株还是新物种。参考文献：(1)D.Dunet al.安。应用程序。比奥尔。125：327,1994。(2)X.周等人。J·维罗尔将军。78：2101,1997。
In 1998, cassava plants exhibiting extremely mild mosaic disease symptoms were collected from Uguja Island, Zanzibar. Total DNAs extracted from symptomatic leaves did not produce diagnostic PCR bands using primers specific to known Cassava mosaic viruses (genus Begomovirus, family Geminiviridae) (2). Degenerate primer pair A/B (1), however, produced a 564-nucleotide (nt) band in the common region of DNA-A to the conserved amino acid sequence CEGPCKYG within the coat protein gene for begomoviruses. Virus-specific primers were designed and the begomoviral genome was amplified and cloned to obtain the full-length DNA-A (2,785 nt) (AF422174) and the partial DNA-B (2,403 nt) (AF422175) component comprising the 5' end of the BV1 open reading frame (ORF) to eight (A) of the conserved nanonucleotide TAATATTAC in the common region. Phylogenetic comparisons of DNA-A and -B sequences of the cassava begomivirus showed they were most closely related to East African cassava mosaic virus (EACMV) from Tanzania (Z83256, 83% identity) and Uganda (AF126805, 87% identity). Based on DNA-A and -B components, its closest relatives among African cassava mosaic virus strains were the Nigerian (X17095, 67% identity) and Ugandan (AF126800, 38% identity) isolates respectively. The number and arrangement of the viral ORF was identical to other bipartite begomoviruses from the Old World. Work is in progress to determine whether this begomovirus is a new strain of an existing EACMV or a new species. References: (1) D. Deng et al. Ann. App. Biol. 125:327, 1994. (2) X. Zhou et al. J. Gen. Virol. 78:2101, 1997.