小RNA深度测序技术分析西瓜花叶病毒蜀葵分离物

蜀葵病毒病害的发生对其生长造成严重影响,明确蜀葵病毒病害的种类及变异进化对蜀葵病毒病害的防治具有重要意义。利用小RNA深度测序技术对具有明显脉明、花叶症状的蜀葵叶片进行鉴定。结果发现,感病蜀葵被西瓜花叶病毒(Watermelon mosaic virus, WMV)、锦葵脉明病毒(Mala vein cleaning virus, MVCV)和一种新的RNA病毒暂命名为蜀葵病毒1号(Althaea rosea virus1, ArV1)]所侵染。为进一步明确WMV蜀葵分离物(WMV-Tg)的进化关系,对病毒WMV-Tg全基因组进行扩增,获得全长为10 046个核苷酸序列(nt)。序列分析结果显示,WMV-Tg与已报道的WMV分离物基因组核苷酸序列的同源性为83.3%～90.2%。系统进化关系表明,WMV-Tg与WMV-Pg聚为一簇,亲缘关系最近。对蜀葵WMV-Tg来源的小RNA(WMV-derived small interfering RNAs, WMV-vsiRNAs)的长度分布、5′碱基偏好性、极性分布以及热点区分布的分析,有助于加深对WMV-vsiRNAs的了解,并为进一步研究病毒来源的小RNA(virus-derived small interfering RNAs, vsiRNAs)在抗病毒防御中的功能,以及为蜀葵病毒病的防治奠定理论基础。

Analysis of Watermelon Mosaic Virus Isolates by Small RNA Deep Sequencing

The occurrence of Althaea rosea(Linn.) virus disease has serious influence on its growth. It is of great significance to clarify the species and mutation evolution of Althaea rosea virus to prevent and control the disease.The small RNA deep sequencing technique was used to identify the leaves of althaea with obvious symptoms of vein clearing and mosaic. It was found that Althaea rosea leaves with typical mosaic symptoms were infected by Watermelon mosaic virus, Mala vein cleaning virus and a new RNA virus, tentatively named Althaea rosea virus 1. In order to further clarify the evolutionary relationship of Althaea rosea isolate, the whole genome of WMV-Tg was amplified and its full-length sequence was 10 046 nucleotides. The reported nucleotide sequence homology of the WMV isolate was 83.3% to 90.2%. The phylogenetic relationship showed that WMV-Tg and WMV-Pg clustered into a cluster, and they are closely related. The analysis of size distribution, 5′-terminal nucleotide preference, strand polarity and hotspot distribution of WMV-Tg-derived small interfering RNAs from Althaea rosea will help us to have a comprehensive understanding of WMV-vsiRNAs and to further study the function of virus-derived small interfering RNAs in antiviral defense. It also lays a theoretical foundation for the prevention and treatment of virus diseases in Althaea rosea.