HC-Pro, a potyvirus RNA silencing suppressor, cancels cycling of Cucumber mosaic virus in Nicotiana benthamiana plants
HC-Pro, a potyvirus RNA silencing suppressor, cancels cycling of Cucumber mosaic virus in Nicotiana benthamiana plants
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DOI：
10.1007/s11262-010-0460-0
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发表时间：
2010-06-01
期刊：
影响因子：
1.6
通讯作者：
Matsumura, Takeshi
中科院分区：
文献类型：
--
作者：
Fukuzawa, Noriho;Itchoda, Noriko;Matsumura, Takeshi
黄瓜花叶病毒(CMV)和马铃薯Y病毒的混合侵染使烟草植株的CMV滴度增加，产生协同的病毒症状。我们发现，在马铃薯Y病毒(PVY)、芜菁花叶病毒(TuMV)和三叶草黄脉病毒(C1YVV)这三种马铃薯Y病毒中，PVY与PVY混合感染对CMV(或重组CMV载体)滴度的协同作用最有效。此外，转基因植物表达的PVY辅助成分--蛋白酶(HC-Pro)基因是一种病毒RNA沉默抑制因子，足以抵消CMV滴度的循环模式，导致CMV总体积累水平增加。令人惊讶的是，我们发现，在HC-Pro转基因植株中，CMV和从CMV载体中表达的外源蛋白的水平远远高于CMV和PVY混合感染的植株中检测到的水平。从RNA沉默与HC-Pro的相互作用以及可能的3a蛋白参与的角度，讨论了单独使用HC-Pro蛋白来消除CMV循环侵染的机制。
The mixed infection of Cucumber mosaic virus (CMV) and a potyvirus has been known to increase CMV titer in Nicotiana benthamiana plants, resulting in synergistic viral symptoms. We found that among three potyviruses-Potato virus Y (PVY), Turnip mosaic virus (TuMV), and Clover yellow vein virus (C1YVV)-synergistic effects on CMV (or a recombinant CMV vector) titers were most efficiently induced by a co-infection with PVY in N. benthamiana plants. In addition, the helper component-proteinase (HC-Pro) gene of PVY expressed by transgenic plants, which is a viral RNA silencing suppressor, was sufficient to cancel the cycling pattern of CMV titer, resulting in increased levels of overall CMV accumulation. Surprisingly, we found that the levels of CMV and the foreign protein expressed from the CMV vector were much higher in the HC-Pro-transgenic plants than the levels detected in the plants mixed-infected with CMV and PVY. The mechanism for canceling the cyclic infection of CMV by the HC-Pro protein alone is discussed in view of the interaction between RNA silencing and HC-Pro, as well as the possible involvement of the 3a protein.