Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
Arch Virol. 2022 Feb;167(2):615-618. doi: 10.1007/s00705-021-05300-x. Epub 2022 Jan 11.
Fatsia japonica is an evergreen shrub native to Japan. For decades, virus-like ringspot symptoms have been observed on leaves of F. japonica in Japan; however, previous attempts to identify the causal agents have been unsuccessful. In this study, we detected an orthotospovirus-like sequence in symptomatic F. japonica plants using RNA sequencing analysis. The complete nucleotide sequences of the L, M, and S segments of the virus were determined using conventional sequencing strategies. The virus had a typical orthotospovirus genome structure, and the putative nucleocapsid protein showed the highest sequence identity to that of groundnut chlorotic fan-spot virus, with 83.7% identity at the amino acid level (which is below the 90% species demarcation cutoff for the genus Orthotospovirus). Although we could not confirm the pathogenicity of the virus in F. japonica due to difficulties associated with mechanical inoculation, its association with the observed symptoms was suggested by the fact that the virus was detected only in symptomatic leaf areas. Based on these results, we consider this virus, which we have named "Fatsia japonica ringspot-associated virus" (FjRSaV), to be the first representative of a new orthotospovirus species, for which we propose the binomial "Orthotospovirus fatsiae".
日本八角金盘是一种原产于日本的常绿灌木。几十年来，日本的八角金盘叶片上一直观察到类病毒环斑症状；然而，先前鉴定致病因子的尝试均未成功。在这项研究中，我们使用 RNA 测序分析在有症状的八角金盘植物中检测到类似 Orthotospovirus 的序列。使用常规测序策略确定了病毒的 L、M 和 S 片段的完整核苷酸序列。该病毒具有典型的 Orthotospovirus 基因组结构，假定的核衣壳蛋白与花生褪绿斑病毒的序列同一性最高，在氨基酸水平上为 83.7%（低于属 Orthotospovirus 的 90%物种划分界限）。尽管由于机械接种相关的困难，我们无法确认该病毒在八角金盘中的致病性，但该病毒仅在有症状的叶片区域检测到，这表明其与观察到的症状有关。基于这些结果，我们认为这种病毒，我们将其命名为“日本八角金盘环斑相关病毒”（FjRSaV），是新的 Orthotospovirus 物种的第一个代表，我们建议其双名法为“Orthotospovirus fatsiae”。
