水稻黑条矮缩病毒江苏玉米分离物全基因组序列及进化分析

利用RT-PCR从江苏玉米上克隆水稻黑条矮缩病毒(RBSDV)的全基因组,其基因组10个片段核苷酸数目和蛋白编码情况与已报道的RBSDV分离物基本一致。基因组的序列一致性分析和系统进化树表明,RBSDV基因组片段间存在频繁的RNA重排现象;江苏玉米分离物(JS)与湖北玉米分离物(HuB)和河北小麦分离物(HeB)的整体亲缘关系较近,而与安徽分离物(AH-MX8)的整体亲缘关系最远。综合本研究及前人对S8和S10的研究,RBSDV基因组不同片段的进化中RNA重组的作用不同:S1、S2和S4中没有RNA重组;S3、S5、S6、S8和S10中存在低频率重组;S7和S9存在较高频率重组,其中S7的高频率重组尤为显著。

Phylogenetic analysis of whole genome of Rice black-streaked dwarf virus isolated from Zea mays in Jiangsu province,China

The whole genome of RBSDV was cloned by RT-PCR from maize in Jiangsu province of China, and designated RBSDV-JS. Size of genome segments and characteristic of ORFs encoded by RBSDV-JS are largely the same as previously reported RBSDV isolates. Nucleotide sequence alignment and phylogenetic trees showed that reassortment among RBSDV isolates occurs frequently. It is also suggested that RBSDV-JS isolate has highest sequence identity with RBSDV-HuB isolated from Hubei province and RBSDV-HeB isolated from Hebei province, and has the lowest similarity with RBSDV-AH-MX8 isolated from Anhui province. Furthermore, RNA recombination played different roles during the evolution of various segments of RBSDV. No RNA recombination was detected in S1, S2 and S4, whereas S3, S5, S6, S8 and S10 showed low-frequency of RNA recombination. For S7 and S9, RNA recombination was frequently detected, especially the S7 segment with a striking high frequency of RNA recombination.