Beijing Research Center for Agricultural Standards and Testing, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
State Key Laboratory of Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100097, China.
Viruses. 2019 Jul 5;11(7):619. doi: 10.3390/v11070619.
Characterization of viroid-derived small RNAs (vd-sRNAs) is important to understand viroid-host interactions; however, vd-sRNAs belonging to the genus are yet to be identified and characterized. Herein, we used coleus plants singly infected with coleus blumei viroid (CbVd)-1, -5, or -6 and doubly infected with CbVd-1 and -5 to identify and analyze their vd-sRNAs. We found sense and antisense vd-sRNAs for CbVd-1, -5 and -6, and 22-nt vd-sRNAs were the most abundant; moreover, the 5'-terminal nucleotides (nts) of CbVd-1, -5, and -6 were biased toward U and C, and sRNAs derived from these three viroids were unevenly distributed along their genomes. We also noted that CbVd-5 and -6 share a fragment that forms the right half of the rod-like secondary structure of these viroids, which implied that they generated almost the same type of vd-sRNAs. This finding indicated that vd-sRNA biogenesis is mainly determined by the primary sequence of their substrates. More importantly, we found two complementary vd-sRNAs (22 nt) that were generated from the central conserved region (CCR) of these three viroids, suggesting an important role of CCR in vd-sRNA biogenesis. In conclusion, our results provide novel insight into the biogenesis of vd-sRNAs and the biological roles of CCR.
研究类病毒衍生的小 RNA（vd-sRNAs）的特征对于理解类病毒-宿主相互作用至关重要；然而，属于的属的 vd-sRNAs 尚未被鉴定和表征。在此，我们使用单独感染了长春花叶病毒（CbVd）-1、-5 或 -6 的长春花植物，以及同时感染了 CbVd-1 和 -5 的长春花植物，来鉴定和分析它们的 vd-sRNAs。我们发现了 CbVd-1、-5 和 -6 的有义和反义 vd-sRNAs，并且 22nt 的 vd-sRNAs 最为丰富；此外，CbVd-1、-5 和 -6 的 5'末端核苷酸（nt）偏向于 U 和 C，并且源自这三种类病毒的 sRNAs 在其基因组上分布不均。我们还注意到，CbVd-5 和 -6 共享一个形成这些类病毒棒状二级结构右半部分的片段，这意味着它们产生了几乎相同类型的 vd-sRNAs。这一发现表明，vd-sRNA 的生物发生主要由其底物的一级序列决定。更重要的是，我们发现了两条来自这三种类病毒中央保守区（CCR）的互补 vd-sRNAs（22nt），这表明 CCR 在 vd-sRNA 的生物发生中起着重要作用。总之，我们的结果为 vd-sRNAs 的生物发生和 CCR 的生物学功能提供了新的见解。
