Jiang Yinhui, Zhang Tingting, Luo Chaoxi, Jiang Daohong, Li Guoqing, Li Qili, Hsiang Tom, Huang Junbin
The Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
Institute of Plant Protection, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi 530007, China.
Virus Res. 2015 Jan 2;195:47-56. doi: 10.1016/j.virusres.2014.08.022. Epub 2014 Sep 6.
Rice false smut caused by Ustilaginoidea virens is a destructive disease in many rice-growing areas. Mycoviruses have been described in many fungal species, but there is little information regarding mycoviruses in U. virens. In this study, double-stranded (ds) RNA banding patterns were assessed in 198 wild-type isolates of U. virens obtained from different geographical regions in China. The presence of viral infections was unusually common in U. virens: 188 of the 198 isolates contained dsRNA elements with viral characteristics, and the presence of mixed infections with two or more related or unrelated mycoviruses was commonly detected. The GX-1 isolate contained four dsRNA mycoviruses: Ustilaginoidea virens RNA virus 1 (UvRV1) belonging to Totiviridae, Ustilaginoidea virens RNA virus 4 (UvRV4) belonging to an unclassified family which includes the Curvularia thermal tolerance virus, and the last two probably belonging to Partitiviridae. Biological comparisons of virus-free and infected fungal isolates revealed that UvRV1 strain GX-1 and UvRV4 were likely cryptic, since the infected strains did not show apparent symptoms or debilitation. Northern blotting experiments revealed that UvRV1 strain GX-1 and UvRV4 were frequently found in U. virens, irrespective of the place of origin, and similarly sized dsRNA bands were not always of similar sequence. Thus, our findings suggest that mycoviruses infecting U. virens in China are widespread and highly diverse.
由稻绿核菌引起的稻曲病是许多水稻种植区的一种毁灭性病害。在许多真菌物种中都已发现了真菌病毒，但关于稻绿核菌中的真菌病毒的信息却很少。在本研究中，对从中国不同地理区域获得的198株稻绿核菌野生型分离株的双链（ds）RNA条带模式进行了评估。病毒感染在稻绿核菌中异常常见：198株分离株中有188株含有具有病毒特征的dsRNA元件，并且经常检测到两种或更多种相关或不相关真菌病毒的混合感染。GX-1分离株含有四种dsRNA真菌病毒：属于双分病毒科的稻绿核菌RNA病毒1（UvRV1）、属于一个未分类科（包括弯孢耐热病毒）的稻绿核菌RNA病毒4（UvRV4），以及最后两种可能属于分病毒科。无病毒和感染病毒的真菌分离株的生物学比较表明，UvRV1菌株GX-1和UvRV4可能是隐性的，因为感染菌株没有表现出明显症状或衰弱。Northern印迹实验表明，无论起源地如何，UvRV1菌株GX-1和UvRV4在稻绿核菌中都经常被发现，并且大小相似的dsRNA条带并不总是具有相似的序列。因此，我们的研究结果表明，在中国感染稻绿核菌的真菌病毒分布广泛且高度多样。
