辣椒轻斑驳病毒湖南分离物的全基因序列测定及结构分析

摘要

采自湖南地区的辣椒轻斑驳病毒Pepper mild mottle virus (PMMoV)样品经单斑分离后,根据已经报道的PMMoV序列基因保守区设计6对简并引物,采用片段重叠法和RACE方法扩增、克隆获得一个全长为6 356 bp的湖南分离物(PMMoV-HN1,登录号:KP345899)全基因组序列,编码4个蛋白,分别为126 kD蛋白(70～3 423 nt)、183 kD蛋白(70～4 908 nt)、28 kD蛋白(4 909～5 682 nt)和17.5 kD蛋白(5 685～6 158 nt),5'-非编码区(5'-UTR)和3'-非编码区(3'UTR)分别含有69和198个碱基,其中5'-UTR存在一个序列为m7G5'pppG的甲基化核苷酸帽子结构.一致性分析发现PMMoV-HN1与PMMoV其他分离物的核酸一致性为94％～99％,编码的氨基酸一致性为94％～99％.全基因组序列系统进化分析表明PMMoV-.HN1分离物与中国首次报道的PMMoV-CN分离物亲缘关系最近.本研究是国内报道的第二例PMMoV全基因组序列.%Pepper samples were collected from Hunan,and identified as Pepper mild mottle virus (PMMoV).According to the previously reported gene conserved regions of PMMoV,six pairs of degenerate primers were designed.The 6 356 bp whole-genome sequence (PMMoV-HN1,accession no.KP345899) was obtained.There were four open reading frames,encoding four proteins,including 126 kD protein (70-3 423 nt),183 kD protein (70-4 908 nt),28 kD protein (4 909-5 682 nt) and 17.5 kD protein (5 685-6 158 nt).The 5'-non-coding region (5'-UTR) and the 3'-non-coding region (3'-UTR) contained 69 and 198 nucleotides,respectively,in which 5'-UTR had a sequence of m7G5'pppG methylation in the nucleotide cap structure.Identity analysis found that the nucleotide identity of PMMoV-HN1 and other PMMoV isolates was 94％-99％,and the identity of the encoded amino acids was 94％-99％.Phylogenetic analysis showed the closest phylogenetic relationships between PMMoV-HN1 and PMMoV-CN.