A unique mitovirus from Glomeromycota, the phylum of arbuscular mycorrhizal fungi
A unique mitovirus from Glomeromycota, the phylum of arbuscular mycorrhizal fungi
复制标题
DOI：
10.1007/s00705-014-1999-1
复制
发表时间：
2014-08-01
影响因子：
2.7
通讯作者：
Ezawa, Tatsuhiro
中科院分区：
文献类型：
--
作者：
Kitahara, Ryoko;Ikeda, Yoji;Ezawa, Tatsuhiro
丛枝菌根(AM)真菌属于球菌门，与大多数陆地植物共生，为寄主植物提供矿质营养。在AM真菌Rhizophagus Clarus菌株RF1中，通过dsRNA的深度测序发现的四个病毒片段中的一个与有丝分裂病毒相似，并在本报告中得到了特征。基因组片段长度为2,895个核苷酸，最大的ORF是通过应用霉菌线粒体或通用遗传密码预测的。ORF编码820个氨基酸的多肽，分子质量为91.2 kDa，保守有丝分裂病毒RdRp超家族的结构域。据此，将该dsRNA命名为R.Clarus mitVirus 1株RF1(RcMV1-RF1)。MitoVirus仅定位于线粒体，因此通常使用霉菌线粒体遗传密码。然而，RcMV1-RF1的独特密码子使用表明，该病毒不仅可以在线粒体中复制，还可以在细胞质中复制。RcMV1-RF1 RdRp与在另一种AM真菌中发现的丝裂病毒样单链RNA的RdRp相似性最高，其次是在子囊菌外生菌根真菌中发现的丝裂病毒的RdRp。在三种菌根真菌中发现的三种有丝分裂病毒形成了一个深分枝的分支，与丝裂病毒属的两个主要分支不同。
Arbuscular mycorrhizal (AM) fungi that belong to the phylum Glomeromycota associate with most land plants and supply mineral nutrients to the host plants. One of the four viral segments found by deep-sequencing of dsRNA in the AM fungus Rhizophagus clarus strain RF1 showed similarity to mitoviruses and is characterized in this report. The genome segment is 2,895 nucleotides in length, and the largest ORF was predicted by applying either the mold mitochondrial or the universal genetic code. The ORF encodes a polypeptide of 820 amino acids with a molecular mass of 91.2 kDa and conserves the domain of the mitovirus RdRp superfamily. Accordingly, the dsRNA was designated as R. clarus mitovirus 1 strain RF1 (RcMV1-RF1). Mitoviruses are localized exclusively in mitochondria and thus generally employ the mold mitochondrial genetic code. The distinct codon usage of RcMV1-RF1, however, suggests that the virus is potentially able to replicate not only in mitochondria but also in the cytoplasm. RcMV1-RF1 RdRp showed the highest similarity to the putative RdRp of a mitovirus-like ssRNA found in another AM fungus, followed by RdRp of a mitovirus in an ascomycotan ectomycorrhizal fungus. The three mitoviruses found in the three mycorrhizal fungi formed a deeply branching clade that is distinct from the two major clades in the genus Mitovirus.