Ziegler-Graff V, Guilford P J, Baulcombe D C
Institut de Biologie Moléculaire des Plantes du CNRS, Université Louis Pasteur, Strasbourg, France.
Virology. 1991 May;182(1):145-55. doi: 10.1016/0042-6822(91)90658-x.
In order to investigate the function of the 29K protein of tobacco rattle virus (TRV), we introduced different mutations in the 29K protein gene and analyzed the biological properties of the subsequent transcripts in tobacco plants. Although none of the mutant RNAs was able to accumulate to a detectable level, the defects in the 29K protein could be complemented by coinoculation with wild-type TRV or tobacco mosaic virus (TMV). Complementation was also achieved in transgenic plants expressing the homologous TMV 30K protein which is involved in cell-to-cell movement, but without inducing distinctive symptoms. Transcripts of chimeric TRV clones containing duplicate genes for the 29K protein initiated infections with formation of necrotic lesions and the progeny retained only one copy of the gene. These experiments demonstrate that the 29K protein is not required for viral RNA replication and, because the TRV transcripts do not encode the coat protein, that the 29K and 30K proteins act on nonencapsidated RNA. In addition to potentiating viral movement, the TRV 29K protein may also play a role in symptom induction on tobacco.
为了研究烟草脆裂病毒（TRV）29K蛋白的功能，我们在29K蛋白基因中引入了不同的突变，并分析了后续转录本在烟草植株中的生物学特性。尽管没有一个突变RNA能够积累到可检测的水平，但29K蛋白中的缺陷可以通过与野生型TRV或烟草花叶病毒（TMV）共接种来互补。在表达参与细胞间运动的同源TMV 30K蛋白的转基因植物中也实现了互补，但没有诱导出明显的症状。含有29K蛋白重复基因的嵌合TRV克隆转录本引发感染并形成坏死斑，后代仅保留该基因的一个拷贝。这些实验表明，病毒RNA复制不需要29K蛋白，并且由于TRV转录本不编码外壳蛋白，29K和30K蛋白作用于未包装的RNA。除了增强病毒运动外，TRV 29K蛋白可能还在烟草的症状诱导中起作用。
