水稻矮缩病毒基因组及毒粒三维结构的研究进展

Development of the study on genome and three-dimensional structure of rice dwarf phytoreovirus

水稻矮缩病毒(Rice dwarf virus,RDV)为双层壳、二十面体的双链 RNA 病毒,是水稻的重要病原物之一。文中比较了 RDV 中国福建分离物与日本分离物基因组各片段核苷酸序列的相似性,发现 RDV 两个不同分离物基因组相应片段的相似性均在92％以上,最高可达96％;分析了相应基因组片段编码的结构蛋白 P1、P2、P3、P5、P7、P8及以前一直被认为是非结构蛋白的 P9和非结构蛋白 Pns4、Pns6、Pns10、Pns11和 Pns12在 RDV 复制、组装过程中的功能;回顾了 RDV 粒子的研究概况,对 RDV 粒子内、外层衣壳的晶体学结构作了较详细的描述;简要介绍了 RDV 复制与组装的机制,发现核心蛋白与 dsRNA 间相互作用成为一个单元是病毒 RNA 的分拣及包装到病毒粒子核心内的可能机制。同时,指出基于 PDR 的植物抗病毒基因工程在水稻矮缩病毒防治上的可能性。

Rice dwarf virus （RDV） is an icosahedral double-shelled particle, and the genome of RDV is composed of 12-segment, double-stranded RNAs. RDV is an important pathogen of rice plant. The similarity of corresponding genome segment of RDV Fujian isolate, in China was compared with that of Japan isolate on nucleotide sequence. The results showed that the similarity was more than 92% between the corresponding segments of the two RDV isolates, and the biggest similarity being 96%. Also, the function of the structure protein P1, P2, P3, PS, P7, P8, including P9 considered as non-structure protein in the past time, and the non-structure proteins Pns4, Pns6, Pns10, Pns11 and Pns12 coded by different genome segments during the course of the replication and assembly of RDV were reviewed. Simultaneously, the development of studies on the 3-dimensional structure of RDV particle was summarized. Especially, the crystallography structures of the inner and outer shell of RDV particle were elucidated. The mechanism of its replication and assembly of RDV particle were presented in brief. Some previous results indicated the core proteins and dsRNAs interact as one unit suggesting a mechanism for assortment of viral RNAs and subsequent packaging into core particles. Finally, we proposed that it be feasible to apply the gene engineering against virus based on parasite-derived resistance （PDR） to control RDV.