苜蓿卷叶病毒山西苜蓿分离物外壳蛋白基因序列分析

Sequence Analysis of CP Gene of Shanxi Alfalfa Isolate of Alfalfa Leaf Curl Virus

苜蓿(Medicago sativa L.)中蛋白质、维生素等多种营养成分含量丰富,是一种在世界范围内被广泛种植的重要牧草,然而苜蓿卷叶病毒(Alfalfa leafcurlvirus,ALCV)的侵染严重影响了苜蓿的品质和产量。为了为苜蓿产业的抗病毒育种提供一定启示,为苜蓿病毒病的防治提供一定的理论依据,研究通过双生病毒通用引物(SPG1/SPG2)在山西省晋中市太谷区山西农业大学植物园中表现出卷曲、皱缩症状的苜蓿样品中检测到ALCV的侵染,并进一步利用PCR技术对ALCV山西苜蓿分离物(ALCV-Taigu)的外壳蛋白(Coatprotein,CP)基因全序列进行克隆和比对分析。结果表明,ALCV-Taigu CP基因与ALCV其他株系核苷酸同源性为82.7%~96.6%,氨基酸同源性为82.4%~97.1%。对ALCV-Taigu CP氨基酸序列系统进化分析表明,ALCV-Taigu与法国、西班牙、意大利等欧洲国家和黎巴嫩、伊朗等中东国家的ALCV分离物距离较远,亲缘关系较远;与中国和阿根廷的ALCV分离物距离较近,聚集为一个大分支,亲缘关系较近;ALCV-Taigu与中国苜蓿ALCV-Helinger/N1分离物距离最近,聚为一簇。这是首次在山西苜蓿上检测到ALCV,该研究结果有助于深入了解ALCV的分子进化。

Alfalfa(Medicago sativa L.)contains various nutrients such as protein and vitamins,and is also an important forage widely planted worldwide.However,the infection of alfalfa leaf curl virus(ALCV)seriously affects the quality and yield of alfalfa.In this study,in order to provide some insights for antiviral breeding in the alfalfa industry,and also provide a theoretical basis for the prevention and control of alfalfa virus diseases.ALCV infection in alfalfa samples with leaf curling and shrinking symptoms in the Botanical Garden of Shanxi Agricultural University,Taigu district,Jinzhong city,Shanxi province was detected,by using the geminivirus universal primer(SPG1/SPG2),and the complete sequence of coat protein(CP)gene of ALCV-Taigu was further cloned and compared by PCR technology.The results showed that the nucleotide homology and amino acid homology of the ALCV-Taigu CP gene with other strains of ALCV were 82.7%–96.6%and 82.4%–97.1%,respectively.The phylogenetic analysis of the amino acid sequence of ALCV-Taigu CP showed that it was far from ALCV isolates from the European countries such as France,Spain,Italy,and the Middle Eastern countries such as Lebanon and Iran,and had a distant genetic relationship.ALCV-Taigu was relatively closed to ALCV isolates from China and Argentina,clustered into a large branch,and had a close genetic relationship.ALCV-Taigu isolate and Chinese alfalfa of ALCV-Helinger/N1 isolate were closely related and clustered together.This was the first time that ALCV had been detected on alfalfa in Shanxi.This study helped to gain a deeper understanding of the molecular evolution of ALCV.