高粱花叶病毒广西甘蔗分离物全基因组序列分析

Complete Genome Sequence Analysis of Sorghum Mosaic Virus from Sugarcane in Guangxi

近年来,高粱花叶病毒(sorghum mosaic virus,SrMV)已成为危害广西甘蔗的主要病原病毒,但尚未见侵染本地区甘蔗的SrMV全基因组序列的报道。本研究以田间一株感染SrMV的甘蔗为材料,提取叶片总RNA通过RT-PCR及RACE技术扩增获得9 626 nt(不包括polyA尾)的病毒全长基因组序列,命名为SrMV-GX。序列分析表明,SrMV-GX与浙江萧山分离物(SrMV-XoS)、浙江余杭分离物(SrMV-YH)和美国德克萨斯州分离物(SrMV-H)的核苷酸同源性分别为95.4%、94.7%和80.9%编码的多聚蛋白氨基酸同源性分别为97.8%、98.4%和90.4%。与马铃薯Y病毒科的其它成员一样,SrMV-GX基因组中存在一个小的ORF(pretty interesting potyviridae ORF,pipo),且其序列非常保守。本研究对SrMV-GX进行序列分析,为进一步研究SrMV的遗传多样性,改进现有的检测方法及培育健康脱毒甘蔗种苗提供理论依据。

Recently, sorghum mosaic virus （SrMV） has become a major pathogenic virus in sugarcane of Guangxi province, which could constitute a serious risk to the sugarcane production. So far, there is no report of a complete genome sequence of SrMV infected sugarcane in Guangxi. The total RNA of sugarcane infected SrMV was ex- tracted and RT-PCR and RACE were used to amplify the full length genome sequence of SrMV. A 9 626 nt viral genome sequence was obtained and named SrMV-GX. Sequence analysis showed that SrMV-GX shared 95.4%, 94.7% and 80.9% nucleotide identity with Xiaoshan isolate （SrMV-XoS）, Yuhang isolate （SrMV-YIt） and Texas isolates （SrMV-H）, respectively. The deduced polyprotein of the SrMV-GX genome shared 97.8%, 98.4%, and 90.4% amino acid identity with SrMV-XoS, SrMV-YH, and SrMV-H, respectively. Just like other members ofpotyviridae, SrMV-GX genome also contained a small ORF pipo （pretty interesting potyviridae ORF）, and its sequence was highly conservative. Our results provided a theoretical basis for further studying the genetic diversity of the SrMV population, improving the diagnostic methods of SrMV, and cultivating virus-free seed cane.