AN EXPERIMENTAL TEST OF THE TRANSMISSION-VIRULENCE TRADE-OFF HYPOTHESIS IN A PLANT VIRUS
AN EXPERIMENTAL TEST OF THE TRANSMISSION-VIRULENCE TRADE-OFF HYPOTHESIS IN A PLANT VIRUS
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DOI：
10.1111/j.1558-5646.2012.01780.x
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发表时间：
2013-02-01
期刊：
影响因子：
3.3
通讯作者：
Michalakis, Yannis
中科院分区：
文献类型：
--
作者：
Doumayrou, Juliette;Avellan, Astrid;Michalakis, Yannis
传播毒力权衡假说是毒力进化的少数适应性解释之一，并假设寄生虫传播和毒力之间存在总体正相关。传播-毒力关系的形状可以预测毒力是否会向最大值或中间最佳值发展。这些性状和宿主内生长之间的正相关往往被认为是毒力和传播之间关系的基础。有几个实验测试这一假设，这项研究报告的第一个经验性测试的植物病原体。我们用九个花椰菜花叶病毒的天然分离物感染芜菁植物，然后估计三个性状：传播，毒力和宿主内病毒积累。正如权衡假设所预测的那样，我们观察到传播和毒力之间存在正相关关系，这表明存在一个中间最佳值。我们发现了两组宿主内积累的意外存在，至少有一个数量级的差异。当积累组不占，宿主内积累相关的毒力，也不传输，虽然我们的研究结果表明，在每个组内存在这些相关性。
The transmissionvirulence trade-off hypothesis is one of the few adaptive explanations of virulence evolution, and assumes that there is an overall positive correlation between parasite transmission and virulence. The shape of the transmissionvirulence relationship predicts whether virulence should evolve toward either a maximum or to an intermediate optimum. A positive correlation between each of these traits and within-host growth is often suggested to underlie the relationship between virulence and transmission. There are few experimental tests of this hypothesis; this study reports on the first empirical test on a plant pathogen. We infected Brassica rapa plants with nine natural isolates of Cauliflower mosaic virus and then estimated three traits: transmission, virulence, and within-host viral accumulation. As predicted by the trade-off hypothesis, we observed a positive correlation between transmission and virulence, suggestive of the existence of an intermediate optimum. We discovered the unexpected existence of two groups of within-host accumulation, differing by at least an order of magnitude. When accumulation groups were not accounted for, within-host accumulation was correlated neither to virulence nor transmission, although our results suggest that within each group these correlations exist.