Resistance to Potato virus Y Mediated by the 3' end Segments of Coat Protein Gene in the Transgenic Tobacco Plants

【Objective】To determine and compare the induction efficiency of RNA silencing triggered by different construction transgene of 3′-terminal segment derived from the Potato virus Y(veinal necrosis strain,PVYN) coat protein gene.【Method】Transgenic tobacco plants expressing untranslated direct repeats(DR) and inverted repeats(IR) of 3′-terminal 202bp of the PVYN coat protein gene were obtained via Agrobacterium tumefaciens-mediated transformation system.【Result】Resistance assay of the transgenic plants indicated that none of the DR-transgenic plants are resistant to PVY,but 82.8% of IR-transgenic plants showed high resistance.Northern blot analysis revealed an inverse correlation between transgene transcript accumulation and virus resistance.【Conclusion】These results showed that the resistance was RNA-mediated.The proportion of the resistant transgenic plants induced by 3′-terminal segment transgene of PVYN is higher than that induced by 5′-terminal segment.