水稻草状矮化病毒基因组RNA1-3的分子生物学  

Molecular Biology of RNA1-3 of Rice Grassy Stunt Virus

作　　者：林丽明[1] 谢联辉[1] 林奇英[1] 

机构地区：[1]福建农林大学,博士研究生福州350002

出　　处：《分子植物育种》2004年第3期449-450,共2页Molecular Plant Breeding

摘　　要：水稻草状矮化病毒(以下简称水稻草矮病毒,Rice grassy stunt vims,RGSV),是纤细病毒属(Tenuivirus)的一个成员,病毒粒体丝状,由核衣壳蛋白和基因组RNA组成。该病于20世纪70年代曾在南亚、东南亚大面积发生,给当地的水稻生产造成严重损失,在我国的福建、台湾、广东、广西和海南等地也有分布。与同属病毒其它成员相比,RGSV分子生物学研究进展较为缓慢,直至1998年才报道病毒基因组全序列,其基因组包含6个ssRNA片段,其中RNA1,2,5和6分别对应于纤细病毒属其它病毒的RNA1-4。6个片段均采用双义编码策略。这不仅在纤细病毒属中,在植物病毒中也是独特的。有鉴于此,本文对水稻草矮病毒沙县分离物(RGSV-SX)RNA1-3的分子生物学及部分基因功能进行了研究(RGSV-SX RNA1-3全长序列已递交GenBank登录,登录号分别为:AF509470、AF511072、AF397468)。根据RGSV菲律宾北方分离物(RGSV-IR)序列设计合成引物,通过RT-PCR获得了覆盖。RGSV-SX基因组RNA1-3的cDNA克隆。序列分析结果表明,RGSV-SX分离物RNA1长9764个核苷酸,与已发表的RGSV菲律宾IR、SC分离物相比,核苷酸序列同源性均为99.6%,其中,NS1蛋白三个分离物间的氨基酸序列同源性为100.0％、RdRP氨基酸序列同源性分别为95.0％、95.0％、99.0％;RNA2全长4071个核苷酸。Rice grassy stunt virus (RGSV) is a member of Tenuivirus. The filamentous particles of RGSV are ribonu-cleo-proteins (RNPs), which are composed of a single nucleocapsid (NC) protein and genomic ssRN A segment. It has caused great losses to rice yield in South and Southeast Asia during the 1970's. It also occurred in the south provinces of China, such as Fujian.Taiwan . Guangdong.Guangxi and Hainan province. Compared with the other members of Tenuivirus, studies on RGSV are lagged. The whole sequence of RGSV-IR genome has been determined until 1998 by Toriyama et al. It revaled that RGSV has six genomic RNA segments, RNA segments 1,2,5 and 6 of RGSV corresponds to RNA 1-4 of the other tenuiviruses. And all six RNA segments had an ambisense coding strategy, it is unique not only in Tenuivirus, but also in other plant virus. On the basis of the results, we proceeded to study the molecular biology of RNA 1-3 of RGSV-SX. With primers designed according to sequence of RGSV-IR isolate, the cDNA clones covering the full-length of RNA 1-3 of SX isolate were obtained by RT-PCR. We determined the complete nucleotide (nt) sequence of RNAs 1(9764nt), 2(4071nt), 3(3120nt) of a Chinese shaxian isolate of rice grassy stunt virus (RGSV-SX) and compared with those of two RGSV isolate (IR and SC) from Philippines. Sequence analysis showed that the overall nucleotide sequence homology was 99.6% with RNA1, 97.6%, 99.3% with RNA2, 98.7%, 91.0% with RNA3, compared with the IR, SC isolates that have been published. RNA2 is most diverged among six RGSV segments, and the nucleotide variation is most in the intergenic region. The results show that it is more homologous between SX and IR than SX and SC. Based on the mentioned results, we conferred that the SX isolate was probably developed from the IR isolate in the Philippines and it is maybe natural occurrence of reassortment during the process of epidemiology. Using recombinant plasmids containing the vRNA3 NS3 gene and vector of pGEX-2T, we constructed the pro

关 键 词：水稻 草状矮化病毒 病毒基因组 RNA1-3 分子生物学 

分 类 号：S511[农业科学—作物学]