An antiviral defense role of AGO2 in plants.
An antiviral defense role of AGO2 in plants.
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DOI：
10.1371/journal.pone.0014639
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发表时间：
2011-01-31
期刊：
影响因子：
3.7
通讯作者：
Baulcombe DC
中科院分区：
文献类型：
--
作者：
Harvey JJ;Lewsey MG;Patel K;Westwood J;Heimstädt S;Carr JP;Baulcombe DC
Argonaute（AGO）蛋白结合小干扰（si）RNA和微（mi）RNA以靶向针对病毒、转基因的RNA沉默和mRNA的调节。植物编码多种AGO蛋白，但在拟南芥中，已知只有AGO1具有抗病毒作用。为了揭示特定AGO在限制病毒积累中的作用，我们将芜菁皱缩病毒（TCV）接种到10个AGO基因中的每一个都突变的拟南芥植物中。大多数植物上的病毒症状与野生型植物上的相同，尽管ago2突变体对该病毒明显超易感。AGO 2植物也对黄瓜花叶病毒（CMV）高度敏感，证实AGO 2的抗病毒作用不是对单一病毒特异的。对于这两种病毒，该表型与病毒蓄积的瞬时增加相关。在野生型植物中，AGO2蛋白由TCV和CMV感染诱导。基于这些结果，我们提出，在植物与病毒的相互作用中，RNA介导的防御和反防御是多层次的。AGO1表示第一层。对于一些病毒，包括TCV和CMV，这一层被可以靶向AGO 1的沉默病毒抑制剂克服，而涉及AGO 2的第二层限制病毒积累。当第一层被抑制时，第二层被激活，因为AGO2通过miR403被AGO1抑制。因此，第二层的激活是失去第一层防御的直接后果。
Argonaute (AGO) proteins bind to small-interfering (si)RNAs and micro (mi)RNAs to target RNA silencing against viruses, transgenes and in regulation of mRNAs. Plants encode multiple AGO proteins but, in Arabidopsis, only AGO1 is known to have an antiviral role. To uncover the roles of specific AGOs in limiting virus accumulation we inoculated turnip crinkle virus (TCV) to Arabidopsis plants that were mutant for each of the ten AGO genes. The viral symptoms on most of the plants were the same as on wild type plants although the ago2 mutants were markedly hyper-susceptible to this virus. ago2 plants were also hyper-susceptible to cucumber mosaic virus (CMV), confirming that the antiviral role of AGO2 is not specific to a single virus. For both viruses, this phenotype was associated with transient increase in virus accumulation. In wild type plants the AGO2 protein was induced by TCV and CMV infection. Based on these results we propose that there are multiple layers to RNA-mediated defense and counter-defense in the interactions between plants and their viruses. AGO1 represents a first layer. With some viruses, including TCV and CMV, this layer is overcome by viral suppressors of silencing that can target AGO1 and a second layer involving AGO2 limits virus accumulation. The second layer is activated when the first layer is suppressed because AGO2 is repressed by AGO1 via miR403. The activation of the second layer is therefore a direct consequence of the loss of the first layer of defense.
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影响因子：
4.9
作者：
Chiu, Meng-Hsuen;Chen, I-Hsuan;Tsai, Ching-Hsiu
通讯作者：
Tsai, Ching-Hsiu
影响因子：
10.5
作者：
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Voinnet, Olivier
DOI：
10.1002/dvg.1020160409
发表时间：
1995-01-01
期刊：
DEVELOPMENTAL GENETICS
影响因子：
--
作者：
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通讯作者：
BARTON, MK
影响因子：
3.5
作者：
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通讯作者：
Carr, JP
影响因子：
14.9
作者：
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通讯作者：
Moorman AF