Differential contributions of plant Dicer-like proteins to antiviral defences against potato virus X in leaves and roots
Differential contributions of plant Dicer-like proteins to antiviral defences against potato virus X in leaves and roots
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DOI：
10.1111/tpj.12770
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发表时间：
2015-03-01
期刊：
影响因子：
7.2
通讯作者：
Suzuki, Nobuhiro
中科院分区：
文献类型：
--
作者：
Andika, Ida Bagus;Maruyama, Kazuyuki;Suzuki, Nobuhiro
植物 Dicer 样 (DCL) 蛋白家族的成员是介导先天抗病毒防御的 RNA 沉默途径的关键组成部分。每种 DCL 蛋白的独特抗病毒作用主要是基于对植物地上部分的观察而确定的。因此，虽然根与许多植物病毒的生命周期密切相关，但人们对根中 DCL 蛋白的抗病毒活性知之甚少。我们观察到抗病毒沉默会强烈抑制马铃薯X病毒（PVX）在一些易感茄科物种根部的复制。本塞姆氏烟草中 DCL4 同源物的沉默部分提高了根中 PVX 的复制水平。在最初被认为是PVX非寄主植物的拟南芥中，通过灭活DCL4实现了接种叶片中高水平的PVX积累，而在上部叶片和根部则需要额外灭活DCL2。在染色体上携带有绿色荧光蛋白 (GFP) 基因插入的 PVX 扩增子的转基因拟南芥 (AMP243 系) 中，DCL4 的缺失使得 PVX-GFP 在各种气生器官中高水平积累，但在根中却不然，这表明 DCL4 对于芽中的细胞内抗病毒沉默至关重要，但在根中却不然，在根中它可以 由其他 DCL 蛋白进行功能补偿。总之，DCL 蛋白之间的高水平功能冗余可能有助于对根中 PVX 复制的有效抗病毒活性。意义声明本研究证明了叶和根之间 DCL 蛋白的差异贡献。
Members of the plant Dicer-like (DCL) protein family are the critical components of the RNA-silencing pathway that mediates innate antiviral defence. The distinct antiviral role of each individual DCL protein has been established with mostly based on observations of aerial parts of plants. Thus, although the roots are closely associated with the life cycle of many plant viruses, little is known about the antiviral activities of DCL proteins in roots. We observed that antiviral silencing strongly inhibits potato virus X (PVX) replication in roots of some susceptible Solanaceae species. Silencing of the DCL4 homolog in Nicotiana benthamiana partially elevated PVX replication levels in roots. In Arabidopsis thaliana, which was originally considered a non-host plant of PVX, high levels of PVX accumulation in inoculated leaves were achieved by inactivation of DCL4, while in the upper leaves and roots, it required the additional inactivation of DCL2. In transgenic A.thaliana carrying the PVX amplicon with a green fluorescent protein (GFP) gene insertion in the chromosome (AMP243 line), absence of DCL4 enabled high levels of PVX-GFP accumulation in various aerial organs but not in the roots, suggesting that DCL4 is critical for intracellular antiviral silencing in shoots but not in roots, where it can be functionally compensated by other DCL proteins. Together, the high level of functional redundancies among DCL proteins may contribute to the potent antiviral activities against PVX replication in roots.Significance StatementThis study demonstrates the differential contributions of DCL proteins between leaves and roots.