木尔坦棉花曲叶病毒V2蛋白N端保守脯氨酸对病毒致病性的影响

Effect of N-terminal conserved proline of Cotton leaf curl Multan virus V2 protein on virus pathogenicity

木尔坦棉花曲叶病毒(CLCuMuV)是棉花曲叶病的主要病原之一,其V2蛋白在病毒致病过程中起重要作用。本研究对V2蛋白N端第4位脯氨酸在病毒致病过程中的作用进行了分析。通过构建马铃薯X病毒(PVX)异源表达载体(PVX-V2、PVX-V2^(P4A)),利用农杆菌介导的方法接种于本氏烟发现,PVX-V2能够增强PVX异源病毒的致病性,致使PVX在植物体内复制量增加,而PVX-V2^(P4A)对PVX异源病毒致病性的影响相对较小。通过构建V2基因突变体(ΔV2、V2^(P4A))侵染性克隆,利用农杆菌介导的方法接种于本氏烟发现,ΔV2、V2^(P4A)侵染性克隆引起的症状较野生型更弱。结果表明,CLCuMuV V2蛋白N端第4位脯氨酸在病毒侵染过程中起重要作用。

Cotton leaf curl Multan virus(CLCu MuV)is one of the main pathogens of cotton leaf curl disease,and its V2 protein plays an important role in the virus pathogenicity.In this study,the role of N-terminal proline at the position 4 of V2 protein on the virus pathogenicity was analyzed.Heterologous Potato virus X(PVX)vectors expressing V2 and V2^(P4A) protein were constructed and inoculated to Nicotiana benthamiana through Agrobacterium.The results showed that PVX-V2 could enhance the pathogenicity of PVX,resulting in an increase in the replication of PVX in plants,while PVX-V2^(P4A) had relatively small impact on the pathogenicity.On the other hand,N.benthamiana plants inoculated with mutant CLCu MuV(ΔV2,V2^(P4A))infectious clone through Agrobacterium showed weaker symptoms than the wild type.These results revealed that proline at the N-terminal(position 4)of CLCu MuV V2 pro-tein played an important role in the process of CLCu MuV infection.