The Evolutionary History of Beet necrotic yellow vein virus Deduced from Genetic Variation, Geographical Origin and Spread, and the Breaking of Host Resistance
The Evolutionary History of Beet necrotic yellow vein virus Deduced from Genetic Variation, Geographical Origin and Spread, and the Breaking of Host Resistance
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DOI：
10.1094/mpmi-10-10-0241
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发表时间：
2011-02-01
影响因子：
3.5
通讯作者：
Tamada, Tetsuo
中科院分区：
文献类型：
--
作者：
Chiba, Soutaro;Kondo, Hideki;Tamada, Tetsuo
甜菜坏死黄脉病毒（Beetnecrotiveyellowveinevirus，BNYVV）是甜菜重要的经济病原，近年来在世界范围内广泛传播，已在世界范围内广泛发现。BNYVV基因组由四个或五个RNA组分组成。在这里，我们报告了73个全球分离株的RNA 3-p25，RNA 4-p31，RNA 2-CP和RNA 5-p26基因的序列变异分析。RNA 3-p25基因编码毒力因子和无毒力因子。这四组基因序列各分为两到四组，其中p25的三组基因组成了八个不同地理分布的亚组。这些亚组分离株（株）中的每一个都可能来自四个原始BNYVV群体及其混合感染。BNYVV的遗传多样性相对较小。选择压力根据BNYVV基因和地理位置而变化很大。分离的意大利菌株，其中p25受到最强的正选择，能够克服Rz 1宿主抗性基因在不同程度上，而其他地理上有限的菌株不能。耐药性破坏变体通过p25第67和68位氨基酸的变化产生。我们的研究表明，BNYVV最初在东亚进化，最近已成为栽培甜菜的病原体，随后出现了新的抗性破坏变异体。
Beet necrotic yellow vein virus (BNYVV) is an economically important pathogen of sugar beet and has been found worldwide, probably as the result of recent worldwide spread. The BNYVV genome consists of four or five RNA components. Here, we report analysis of sequence variation in the RNA3-p25, RNA4-p31, RNA2-CP, and RNA5-p26 genes of 73 worldwide isolates. The RNA3-p25 gene encodes virulence and avirulence factors. These four sets of gene sequences each fell into two to four groups, of which the three groups of p25 formed eight subgroups with different geographical distributions. Each of these subgroup isolates (strains) could have arisen from four original BNYVV population and their mixed infections. The genetic diversity for BNYVV was relatively small. Selection pressure varied greatly depending on the BNYVV gene and geographical location. Isolates of the Italy strain, in which p25 was subject to the strongest positive selection, were able to overcome the Rz1-host resistance gene to differing degrees, whereas other geographically limited strains could not. Resistance-breaking variants were generated by p25 amino acid changes at positions 67 and 68. Our studies suggest that BNYVV originally evolved in East Asia and has recently become a pathogen of cultivated sugar beet followed by the emergence of new resistance-breaking variants.