中文摘要：

为了探明微管结合蛋白70（MAP70）在抗马铃薯Y病毒（PVY）中的作用机制,克隆了烟草AW4P70基因的全长,并进行了生物信息学分析.利用实时荧光定量PCR研究了该基因在烟草不同时期和不同部位中的表达水平,结果表明,斯-M4P70在烟草的各个生长期均有表达,且在根中的表达量最高.构建了基于双生病毒卫星诱导的烟草斯M4P70的沉默载体,以中国番茄黄化曲叶病毒（TYLCCNV）为辅助病毒在烟草中沉默了该基因.与对照相比,在AWW70基因沉默的烟草中PVY侵染速率明显减缓,病毒含量显著降低.

英文摘要：

To elucidate the mechanism of microtubule-associated protein 70 （MAP70） on combating Potato virus Y （ PVY ）,full- length NtMAP70 was firstly isolated,and transcriptional expression levels of NtMAP70 in different organs and growing periods were measured by real-time quantitative PCR. Then NtMAP70 gene silencing vector,based on geminivirus satellite,was introduced into Agrobacterium tumefaciens strain EHA105. And Agrobecterium harboring recombinant silencing vector and Tomato yellow leaf curl China virus （TYLCCNV） infectious clone were coagroinoculated into tobacco plants. Results showed that NtMAP70 was expressed in all organs and growing periods,among which the expression levels was highest in the root. Compared with the control,PVY infection rate was lower in tobacco plants that inoculated with silenced gene so as a reduced level of PVY. To summarize,silenced Nt- MAP70 gene is very likely to suppress the proliferation of PVY and retard its activity.