Aphid-borne Viral Spread Is Enhanced by Virus-induced Accumulation of Plant Reactive Oxygen Species
Aphid-borne Viral Spread Is Enhanced by Virus-induced Accumulation of Plant Reactive Oxygen Species
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病毒诱导的植物活性氧积累增强了蚜虫传播的病毒传播
DOI：
10.1104/pp.18.00437
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发表时间：
2019-01-01
期刊：
影响因子：
7.4
通讯作者：
Sun, Yucheng
中科院分区：
文献类型：
--
作者：
Guo, Huijuan;Gu, Liyuan;Sun, Yucheng
大多数已知的植物病毒通过昆虫媒介在植物之间传播。有强有力的证据表明，非持续性传播的病毒操纵植物挥发物的释放，以吸引昆虫媒介，从而促进病毒的传播。然而，蚜虫在感染这些病毒的植物上的定居和进食发生改变的机制尚不清楚。在这里，我们采用了黄瓜花叶病毒（CMV）和它的宿主植物之一，烟草（烟草）的功能丧失突变，阐明这样的机制。我们表明，相对于删除CMV中RNAi 2b蛋白的病毒抑制子的CMV Delta 2b株系，感染野生型CMV的植物在植物组织中产生更高浓度的活性氧（ROS）H2O2。蚜虫在野生型CMV感染的植物从事较短的探针，韧皮部喂养，并表现出其他变化，如检测到的电穿透绘图技术，相对于CMV三角洲2b感染的植物。因此，病毒收购的频率和病毒载量每蚜虫上CMV感染的植物比CMV三角洲2b感染的植物。蚜虫也从最初的喂养地点更频繁地移动到野生型CMV感染的CMV Delta 2b感染的植物。H2O2在引发这些影响蚜虫的作用得到证实，使用健康的植物注入H2O2。最后，H2O2水平没有升高，蚜虫的行为是不变的，在CMV感染RbohD沉默的烟草植物，这是在诱导活性氧产生的缺陷。这些结果表明，CMV利用其RNAi蛋白的病毒抑制子来增加植物ROS水平，从而增强其通过载体昆虫的获取和传播。
Most known plant viruses are spread from plant to plant by insect vectors. There is strong evidence that nonpersistently transmitted viruses manipulate the release of plant volatiles to attract insect vectors, thereby promoting virus spread. The mechanisms whereby aphid settling and feeding is altered on plants infected with these viruses, however, are unclear. Here we employed loss-of-function mutations in cucumber mosaic virus (CMV) and one of its host plants, tobacco (Nicotiana tabacum), to elucidate such mechanisms. We show that, relative to a CMV Delta 2b strain with a deletion of the viral suppressor of RNAi 2b protein in CMV, plants infected with wild-type CMV produce higher concentrations of the reactive oxygen species (ROS) H2O2 in plant tissues. Aphids on wild-type CMV-infected plants engage in shorter probes, less phloem feeding, and exhibit other changes, as detected by electrical penetration graphing technology, relative to CMV Delta 2b-infected plants. Therefore, the frequency of virus acquisition and the virus load per aphid were greater on CMV-infected plants than on CMV Delta 2b-infected plants. Aphids also moved away from initial feeding sites more frequently on wild-type CMV infected versus CMV Delta 2b-infected plants. The role of H2O2 in eliciting these effects on aphids was corroborated using healthy plants infused with H2O2. Finally, H2O2 levels were not elevated, and aphid behavior was unchanged, on CMV-infected RbohD-silenced tobacco plants, which are deficient in the induction of ROS production. These results suggest that CMV uses its viral suppressor of RNAi protein to increase plant ROS levels, thereby enhancing its acquisition and transmission by vector insects.