Wei Shiqing, Liu Linwen, Chen Guoliang, Yang Hui, Huang Liang, Gong Guoshu, Luo PeiGao, Zhang Min
College of Agronomy, Sichuan Agricultural University, Chengdu, China.
State Key Laboratory for the Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Front Microbiol. 2024 Feb 14;15:1314526. doi: 10.3389/fmicb.2024.1314526. eCollection 2024.
Wheat dwarf virus (WDV) has caused considerable economic loss in the global production of grain crops. Knowledge of the evolutionary biology and population history of the pathogen remain poorly understood. We performed molecular evolution and worldwide phylodynamic analyses of the virus based on the genes in the protein-coding region of the entire viral genome. Our results showed that host-driven and geography-driven adaptation are major factors that affects the evolution of WDV. Bayesian phylogenetic analysis estimates that the average WDV substitution rate was 4.240 × 10 substitutions/site/year (95% credibility interval, 2.828 × 10-5.723 × 10), and the evolutionary rates of genes encoding proteins with virion-sense transcripts and genes encoding proteins with complementary-sense transcripts were different. The positively selected sites were detected in only two genes encoding proteins with complementary-sense, and WDV-barley are subject to stronger purifying selection than WDV-wheat. The time since the most recent common WDV ancestor was 1746 (95% credibility interval, 1517-1893) CE. Further analyses identified that the WDV-barley population and WDV-wheat population experienced dramatic expansion-decline episodes, and the expansion time of the WDV-barley population was earlier than that of the WDV-wheat population. Our phylogeographic analysis showed that the WDV population originating in Iran was subsequently introduced to Europe, and then spread from Eastern Europe to China.
小麦矮缩病毒（WDV）已在全球粮食作物生产中造成了相当大的经济损失。人们对该病原体的进化生物学和种群历史仍知之甚少。我们基于整个病毒基因组蛋白质编码区的基因，对该病毒进行了分子进化和全球系统动力学分析。我们的结果表明，宿主驱动和地理驱动的适应性是影响WDV进化的主要因素。贝叶斯系统发育分析估计，WDV的平均替换率为4.240×10⁻⁵替换/位点/年（95%可信区间，2.828×10⁻⁵ - 5.723×10⁻⁵），并且编码病毒义转录本蛋白的基因和编码互补义转录本蛋白的基因的进化速率不同。仅在两个编码互补义蛋白的基因中检测到正选择位点，并且WDV - 大麦比WDV - 小麦受到更强的纯化选择。最近共同的WDV祖先出现的时间为公元1746年（95%可信区间，1517 - 1893）。进一步分析发现，WDV - 大麦种群和WDV - 小麦种群经历了剧烈的扩张 - 衰退过程，并且WDV - 大麦种群的扩张时间早于WDV - 小麦种群。我们的系统地理学分析表明，起源于伊朗的WDV种群随后被引入欧洲，然后从东欧传播到中国。
