Nicolini C, Pio-Ribeiro G, Andrade G P, Melo F L, Oliveira V C, Guimarães F C, Resende R O, Kitajima E W, Rezende J A M, Nagata Tatsuya
Laboratório de Fitovirologia, Departamento de Agronomia, Universidade Federal Rural de Pernambuco, Recife, PE 52171-900, Brazil.
Virus Genes. 2012 Aug;45(1):190-4. doi: 10.1007/s11262-012-0750-9. Epub 2012 Apr 25.
Leaves of Cassia hoffmannseggii, a wild fabaceous species found in the Atlantic Forest, with a severe mosaic symptom were collected in Pernambuco State, Brazil. By transmission electron microscopy, two types of virus particles were found: the first was recognized as particles of a potyvirus, which was later identified as Cowpea aphid-borne mosaic virus; and the second was isometric and present in high concentration. The observation of vesicles at the periphery of chloroplasts suggested a tymovirus infection, which was confirmed by subsequent assays. A serological assay against several tymovirus antisera resulted in positive reaction of this tymo-like virus with an antiserum of Passion fruit yellow mosaic virus. By means of RT-PCR and using degenerated primers for the conserved region of RNA-dependent RNA polymerase (RdRp) gene of tymoviruses, a specific DNA fragment was amplified and sequenced. Based on this sequence, a specific forward primer was synthesized and successfully used to amplify the 3' terminal genome region, containing the partial RdRp gene and the complete coat protein (CP) sequences. The CP was 188 amino acids (aa) long, and the highest CP aa identity was observed with Kennedya yellow mosaic virus (61 %). Based on the current ICTV demarcation criterion, this isolate was considered as a distinct tymovirus and tentatively named as Cassia yellow mosaic-associated virus.
在巴西伯南布哥州采集了霍夫曼决明（Cassia hoffmannseggii）的叶片，该野生豆科植物生长于大西洋森林，呈现严重的花叶症状。通过透射电子显微镜观察，发现了两种病毒粒子：第一种被识别为马铃薯Y病毒属病毒粒子，后来被鉴定为豇豆蚜传花叶病毒；第二种呈等轴状且浓度很高。叶绿体周边出现囊泡的现象表明存在番茄病毒属病毒感染，后续检测证实了这一点。针对几种番茄病毒属病毒抗血清的血清学检测结果显示，这种类番茄病毒与西番莲黄化花叶病毒抗血清呈阳性反应。利用逆转录聚合酶链反应（RT-PCR）并使用针对番茄病毒属病毒依赖RNA的RNA聚合酶（RdRp）基因保守区域的简并引物，扩增并测序得到一个特定的DNA片段。基于该序列，合成了一条特定的正向引物，并成功用于扩增3'端基因组区域，该区域包含部分RdRp基因和完整的外壳蛋白（CP）序列。CP由188个氨基酸（aa）组成，与肯尼迪亚黄化花叶病毒的CP氨基酸一致性最高（61%）。根据国际病毒分类委员会目前的分类标准，该分离株被视为一种独特的番茄病毒属病毒，并暂定名为决明黄化花叶相关病毒。
