Initiation and maintenance of virus-induced gene silencing
Initiation and maintenance of virus-induced gene silencing
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DOI：
10.1105/tpc.10.6.937
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发表时间：
1998-06-01
期刊：
影响因子：
11.6
通讯作者：
Baulcombe, DC
中科院分区：
文献类型：
--
作者：
Ruiz, MT;Voinnet, O;Baulcombe, DC
在携带PDS插入片段的马铃薯X病毒(PVX)载体中，本氏烟草的植酸烯去饱和酶(PDS)基因被沉默，在PVX-GFP感染的植株中，绿色荧光蛋白(GFP)转基因被沉默。这种病毒诱导的基因沉默(VIGS)是转录后和细胞质的，因为它针对PDS RNA的外显子而不是内含子，并针对病毒RNA。尽管PDS和GFP RNA很可能通过相同的机制被靶向，但VIGS的表型在两个方面有所不同。VIGS在PVX-PDS侵染植株的所有绿色组织中都以PDS mRNA为靶标，而PVX-PDS不受影响。相反，GFP的VIGS是针对PVX-GFP的。最初，绿色荧光蛋白的VIGS在所有绿色组织中启动，就像PDS VIGS一样。然而，在侵染30天后，GFP VIGS在新生的叶片中不再启动，尽管它保持在已经启动的组织中。基于这些分析，我们提出了一个VIGS模型，在该模型中，VIGS的启动依赖于病毒，而维护是独立于病毒的。
The phytoene desaturase (PDS) gene of Nicotiana benthamiana was silenced in plants infected with potato virus X (PVX) vectors carrying PDS inserts, and a green fluorescent protein (GFP) transgene was silenced in plants infected with PVX-GFP. This virus-induced gene silencing (VIGS) is post-transcriptional and cytoplasmic because it is targeted against exons rather than introns of PDS RNA and against viral RNAs. Although PDS and GFP RNAs are most likely targeted through the same mechanism, the VIGS phenotypes differed in two respects. PDS mRNA was targeted by VIGS in all green tissue of the PVX-PDS-infected plant, whereas PVX-PDS was not affected. In contrast, VIGS of the GFP was targeted against PVX-GFP. Initially, VIGS of the GFP was initiated in all green tissues, as occurred with PDS VIGS. However, after 30 days of infection, the GFP VIGS was no longer initiated in newly emerging leaves, although it was maintained in tissue in which it had already been initiated. Based on these analyses, we propose a model for VIGS in which the initiation of VIGS is dependent on the virus and maintenance of it is virus independent.