Characterization of a Novel Mitovirus Infecting Melanconiella theae Isolated From Tea Plants.
Characterization of a Novel Mitovirus Infecting Melanconiella theae Isolated From Tea Plants.
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从茶树中分离的感染茶黑霉的新型线粒体病毒的表征
DOI：
10.3389/fmicb.2021.757556
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发表时间：
2021
影响因子：
5.2
通讯作者：
Xu W
中科院分区：
文献类型：
--
作者：
Shafik K;Umer M;You H;Aboushedida H;Wang Z;Ni D;Xu W
从茶树上分离的茶黑孢霉（Melanconiella theae）中鉴定出一个dsRNA片段。通过随机克隆和RACE方案确定的完整dsRNA序列长度为2，461 bp，AU含量丰富（62.37%），并且包含编码RNA依赖性RNA聚合酶（RdRp，大小为754个氨基酸）的2，265个核苷酸的单个ORF。末端序列可以折叠成预测的稳定茎环结构。BLASTX和系统发育分析显示，dsRNA基因组显示与有丝分裂病毒的RdRp序列相似，与葡萄相关的有丝分裂病毒20和Colletotrichum fructicola有丝分裂病毒1的最高同源性为48%。我们的研究结果表明，一个新的成员，暂命名为Melanconiella茶有丝分裂病毒1（MtMV 1），属于线粒体病毒科。透射电镜观察表明，MtMV 1无衣壳，分生孢子能有效传播，菌丝倾翻法结合绿茶粉可有效消除MtMV 1。MtMV 1的基因组序列与线粒体病毒科（Mitoviridae）大部分成员的基因组序列明显不同，并且具有一些在已知成员中未见报道的独特特征。这是迄今为止首次报道的一种真菌病毒感染黑锥菌属真菌。
A dsRNA segment was identified in the fungus Melanconiella theae isolated from tea plants. The complete dsRNA sequence, determined by random cloning together with RACE protocol, is 2,461 bp in length with an AU-rich content (62.37%) and comprises a single ORF of 2,265-nucleotides encoding an RNA-dependent RNA-polymerase (RdRp, 754 amino acids in size). The terminus sequences can fold into predicted stable stem-loop structures. A BLASTX and phylogenetic analysis revealed the dsRNA genome shows similarities with the RdRp sequences of mitoviruses, with the highest identity of 48% with those of grapevine-associated mitovirus 20 and Colletotrichum fructicola mitovirus 1. Our results reveal a novel member, tentatively named Melanconiella theae mitovirus 1 (MtMV1), belongs to the family Mitoviridae. MtMV1 is capsidless as examined by transmission electron microscope, efficiently transmitted through conidia as 100 conidium-generated colonies were analyzed, and easily eliminated by hyphal tipping method combined with green-leaf tea powder. MtMV1 has a genomic sequence obviously divergent from those of most members in the family Mitoviridae and some unique characteristics unreported in known members. This is the first report of a mycovirus infecting Melanconiella fungi to date.