Turnip mosaic virus Moves Systemically through Both Phloem and Xylem as Membrane-Associated Complexes
Turnip mosaic virus Moves Systemically through Both Phloem and Xylem as Membrane-Associated Complexes
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DOI：
10.1104/pp.15.00097
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发表时间：
2015-04-01
期刊：
影响因子：
7.4
通讯作者：
Laliberte, Jean-Francois
中科院分区：
文献类型：
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作者：
Wan, Juan;Cabanillas, Daniel Garcia;Laliberte, Jean-Francois
植物病毒通过韧皮部系统地在植物中传播。它们以病毒粒子或核糖核蛋白复合物的形式移动，尽管尚不清楚这些复合物是由什么构成的。芜菁花叶病毒（TuMV）大约10kb的RNA基因组编码一种称为6K(2)的膜蛋白，该蛋白诱导膜重排以形成病毒复制工厂。这些工厂以囊泡的形式存在，囊泡中含有病毒RNA （vRNA）和病毒复制蛋白。在这项研究中，我们报道了在韧皮部筛元件和木质部导管中存在含有vRNA和vRNA依赖性RNA聚合酶的6K(2)标记囊泡。透射电镜观察显示木质部导管中存在含有vrna的囊泡，这些囊泡与病毒颗粒有关。茎环剥实验使木质部血管完好无损，但破坏了周围组织，证实了TuMV可以通过木质部血管对植物进行全身感染。马铃薯x病毒感染植株的韧皮部筛元件和木质部导管中也含有脂相关的非囊化vRNA，这表明韧皮部和木质部中存在膜相关核糖核蛋白复合物可能并不局限于TuMV。总的来说，这些研究表明，病毒复制工厂可能最终在韧皮部和木质部。
Plant viruses move systemically in plants through the phloem. They move as virions or as ribonucleic protein complexes, although it is not clear what these complexes are made of. The approximately 10-kb RNA genome of Turnip mosaic virus (TuMV) encodes a membrane protein, known as 6K(2), that induces endomembrane rearrangements for the formation of viral replication factories. These factories take the form of vesicles that contain viral RNA (vRNA) and viral replication proteins. In this study, we report the presence of 6K(2)-tagged vesicles containing vRNA and the vRNA-dependent RNA polymerase in phloem sieve elements and in xylem vessels. Transmission electron microscopy observations showed the presence in the xylem vessels of vRNA-containing vesicles that were associated with viral particles. Stem-girdling experiments, which leave xylem vessels intact but destroy the surrounding tissues, confirmed that TuMV could establish a systemic infection of the plant by going through xylem vessels. Phloem sieve elements and xylem vessels from Potato virus X-infected plants also contained lipid-associated nonencapsidated vRNA, indicating that the presence of membrane-associated ribonucleic protein complexes in the phloem and xylem may not be limited to TuMV. Collectively, these studies indicate that viral replication factories could end up in the phloem and the xylem.