Characterization of DNAbeta associated with begomoviruses in China and evidence for co-evolution with their cognate viral DNA-A.
Characterization of DNAbeta associated with begomoviruses in China and evidence for co-evolution with their cognate viral DNA-A.
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DOI：
10.1099/vir.0.18608-0
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Xue-ping Zhou;Yan Xie;Xiaorong Tao;Zhong-kai Zhang;Zhenghe Li;C. Fauquet
中科院分区：
文献类型：
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作者：
Xue-ping Zhou;Yan Xie;Xiaorong Tao;Zhong-kai Zhang;Zhenghe Li;C. Fauquet
从云南地区的烟草、番茄和杂草中分离得到18份begomovirus样本，其中dna abeta分子的完整核苷酸序列包含1333 ~ 1355 nt。所鉴定的18个DNAbeta分子主要分为3个类型，每个类型与不同的begomovirus种相关，其中一种类型的核苷酸同源性为72 ~ 99%，而两种类型之间的核苷酸同源性仅为39 ~ 57%。这里和其他地方报道的所有dna abeta分子都包含一个115 nt的保守区域，与一致序列具有93- 100%的一致性，并且在互补链（称为C1）上具有一个共同的ORF，编码118个氨基酸。将中国番茄黄曲叶病毒烟草分离物Y10的DNA-A组分及其相关dna β (Y10 β)共混接种，表明该dna β参与了烟草和番茄的症状诱导。与野生的Y10beta相比，Y10beta的C1框内ATG突变引起的症状要轻得多，这表明该ORF具有功能性作用。dna abeta分子与其同源病毒DNA-A分子的配对核苷酸序列一致性比较表明，dna abeta分子与其同源辅助病毒共同进化。dna abeta分子之间的重组被记录，并提出和讨论了dna abeta物种的概念。
Eighteen samples of begomoviruses isolated from tobacco, tomato and weed species in Yunnan, China were found to be associated with DNAbeta molecules, for which the complete nucleotide sequences were found to contain 1333-1355 nt. The 18 DNAbeta molecules identified consist of three main types, each associated with a different begomovirus species: 72-99 % nucleotide identity was found within one type, but only 39-57 % identity was found between types. All the DNAbeta molecules reported here and elsewhere contain a 115 nt conserved region that has 93-100 % identity with a consensus sequence, and have a common ORF encoding 118 amino acids on the complementary strand (designated C1). Co-agroinoculation of the DNA-A component of Tomato yellow leaf curl China virus tobacco isolate Y10, with its associated DNAbeta (Y10beta), shows this DNAbeta to be involved in symptom induction in tobacco and tomato. The in-frame ATG mutation of C1 of Y10beta caused much milder symptoms as compared with wild Y10beta, indicating a functional role for this ORF. Pairwise nucleotide sequence identity comparisons of DNAbeta molecules and their cognate viral DNA-A molecules indicate that DNAbeta molecules have co-evolved with their cognate helper viruses. Recombination between DNAbeta molecules is documented and a DNAbeta species concept is proposed and discussed.