中文摘要：病毒衍生的siRNAs（vsiRNAs）介导的RNA沉默在植物病毒与寄主交互作用中发挥了重要的作用。南方水稻黑条矮缩病毒（SRBSDV）是一种新出现的具有毁灭性的水稻呼肠孤病毒，具有10个dsRNA基因片段。但SRBSDV衍生的siRNAs特征及其在SRBSDV-水稻交互作用中的生物影响仍未有研究。本研究结果表明，SRBSDV可以调节水稻RNA沉默途径成分的表达，病毒可能会向寄主防御妥协并通过siRNA途径影响寄主的发病机制。
外文摘要：Background: Virus-derived siRNAs (vsiRNAs)-mediated RNA silencing plays important roles in interaction between plant viruses and their hosts. Southern rice black-streaked dwarf virus (SRBSDV) is a newly emerged devastating rice reovirus with ten dsRNA genomic segments. The characteristics of SRBSDV-derived siRNAs and their biological implications in SRBSDV-rice interaction remain unexplored. Methods: VsiRNAs profiling from SRBSDV-infected rice samples was done via small RNA deep sequencing. The putative rice targets of abundantly expressed vsiRNAs were bioinformatically predicted and subjected to functional annotation. Differential expression analysis of rice targets and RNA silencing components between infected and healthy samples was done using RT-qPCR. Results: The vsiRNA was barely detectable at 14 days post infection (dpi) but abundantly present along with elevated expression level of the viral genome at 28 dpi. From the 28-dpi sample, 70,878 reads of 18 similar to 30-nt vsiRNAs were recognized (which mostly were 21-nt and 22-nt), covering 75 similar to 91% of the length of the ten genomic segments respectively. 86% of the vsiRNAs had a < 50% GC content and 79% of them were 5'-uridylated or adenylated. The production of vsiRNAs had no strand polarity but varied among segment origins. Each segment had a few hotspot regions where vsiRNAs of high abundance were produced. 151 most abundant vsiRNAs were predicted to target 844 rice genes, including several types of host resistance or pathogenesis related genes encoding F-box/LRR proteins, receptor-like protein kinases, universal stress proteins, tobamovirus multiplication proteins, and RNA silencing components OsDCL2a and OsAGO17 respectively, some of which showed down regulation in infected plants in RT-qPCR. GO and KEGG classification showed that a majority of the predicted targets were related to cell parts and cellular processes and involved in carbohydrate metabolism, translation, and signal transduction. The silencing component genes OsDCL2a, OsDCL2b, OsDCL4, and OsAGO18 were down regulated, while OsAGO1d, OsAGO2, OsRDR1 and OsRDR6 were up regulated, significantly, upon SRBSDV infection. Conclusions: SRBSDV can regulate the expression of rice RNA silencing pathway components and the virus might compromise host defense and influence host pathogenesis via siRNA pathways.
外文关键词：Southern rice black-streaked dwarf virus; Virus-derived siRNAs; RNA silencing; Deep sequencing; RT-qPCR; Host defense; Target genes
作者：Xu, Donglin; Zhou, Guohui
作者单位：华南农业大学
期刊名称：VIROLOGY JOURNAL
期刊影响因子：2.362
出版年份：2017
出版刊次：2
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