The genus Tobravirus comprises three species: Tobacco rattle virus, Pea early-browning virus and Pepper ringspot virus. The genomes of tobraviruses consist of two positive-sense single-stranded RNA segments (RNA1 and RNA2). Infectious clones of TRV are extensively used as virus-induced gene-silencing (VIGS) vectors for studies of virus-host interactions and functions of plant genes. Complete infectious clones of pepper ringspot virus (PepRSV), the only tobravirus present in Brazil, however, have not yet been reported. Infectious clones will help to identify unique features of PepRSV RNA2 and provide another option for development of VIGS vectors. We constructed infectious clones based on two PepRSV isolates, CAM (RNA1 and RNA2) and LAV (RNA2). The cDNA constructs for both homologous (RNA1 and RNA2 of the CAM isolate) and heterologous (RNA1/CAM and RNA2/LAV) combinations were infectious in Nicotiana benthamiana plants. VIGS vector constructs with green fluorescent protein or phytoene desaturase genes inserted in RNA2 silenced the target genes. The systemic translocation of the PepRSV RNA1 construct alone (nonmultiple infection) was also confirmed in an N. benthamiana plant. These results are similar to those reported for tobacco rattle virus.

中文翻译：

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胡椒环斑病毒感染性克隆的表征及其作为病毒载体的用途。

烟草花叶病毒属包括三种：烟草吵闹病毒，豌豆早褐病毒和胡椒环斑病毒。妥布病毒的基因组由两个正向单链RNA片段（RNA1和RNA2）组成。TRV的感染性克隆被广泛用作病毒诱导的基因沉默（VIGS）载体，用于研究病毒-宿主相互作用和植物基因的功能。胡椒环斑病毒（PepRSV）的完整感染性克隆是巴西唯一的脑膜炎病毒，但尚未见报道。感染性克隆将有助于鉴定PepRSV RNA2的独特功能，并为开发VIGS载体提供另一种选择。我们基于两个PepRSV分离株CAM（RNA1和RNA2）和LAV（RNA2）构建了感染性克隆。同源（CAM分离株的RNA1和RNA2）和异源（RNA1 / CAM和RNA2 / LAV）组合的cDNA构建体在本生烟草植物中具有传染性。VIGS载体构建体带有插入RNA2的绿色荧光蛋白或八氢番茄红素去饱和酶基因，使目标基因沉默。在本氏烟草中也证实了单独的PepRSV RNA1构建体的系统易位（非多重感染）。这些结果与烟草拨浪鼓病毒的报道相似。