PVY~N CP gene silencing and transgenic resistance to PVY~n are temperature dependent in tobacco

The influence of temperature on RNA silencing and the level of resistance in transgenic tobacco plants was studied by using Northern blotting and ELISA to detect the virus in T3 plants that contain untranslatable PVYN CP gene. The results shown that low temperature could change the RNA silencing that had occurred in transgenic plants and the resistance status. RNA silencing obtained by transgene was inhibited in plants grown at 15℃. The plants lost the characteristic of high resistance and displayed the symptom of susceptibility. RNA silencing obtained by transgene was not inhibited, however, in the transgenic plants that grown at 25℃ or above,i. e. 30℃ and 35℃. The transgenic plants maintained high resistance against PVYN virus.