RNAi with natural defence mechanism of homologous RNA degradation is widely used in research of antiviral plant.It is important to construct a highly efficent RNAi vector for transgenic plants of virus resis-tance.In this study,part fragments of coat protein gene of Potato virus Y(PVY)(451-750 bp) were inserted into the two expression vectors.Vector pROKY300 without intron and pHelY300 with PDK and CAT introns on the hpRNA stem were constructed.The silence efficiency of virus resistance of the two vectors was investigated as 88%(22/25)for pROKY300 and 92%(23/25) for pHelY300 through transient expression mediated by agroinfiltration.The results showed that both vectors were highly antiviral and elucidated the validity of RNAi-medicates resistance to virus.
