High Level of Field Resistance of Transgenic Tobaccos Induced by Integrated Potato Virus Y Coat Protein Gene

Abstract

The coat protein gene (CP) from a highly virulent, necrotic and dominant strain of potato virus Y (PVY) originated from the Hungarian flora has been engineered via Agrobacterium infection into different Hungarian tobacco breeding lines and cultivars. The integration of the CP was confirmed by polymerase chain reaction (PCR) using genomic preparations. The transcription and the expression of the integrated CP gene were detected by Northern and Western analysis. The pathogen-derived resistance was demonstrated by inoculation of the R1 progeny of transformant plants with purified PVY. The efficiency of the protection varied between different transgenic tobaccos ranging from complete to no protection. The challenge infection of the plants was monitored by dot blot hybridisation at different intervals after mechanical inoculation.Western blot analysis showed that there is no correlation between the level of expressed CP and the extent of resistance. From tobacco cultivars namely Virgin D, Stamm C2 and Hevesi 11, 38, 55 and 23 transformants were obtained, respectively. After several years of greenhouse experiments, only the extreme resistant tobaccos were planted field under the special licence, given by the competent authority. In field conditions, transgenic tobacco varieties showed extreme resistance against natural infection of PVY.

Potato virus Y coat protein gene induced resistance in valuable potato cultivars

“…A necrotic strain of potato virus Y (PVY-H) used (de Bokx and Huttinga, 1981;Beczner et al, 1984;Thole et al, 1993) labelled today as a PVY NTN as a source for construction of the CP gene containing plant expression vector described elsewhere in details (Kollár et al, 1993;Józsa et al, 2002). For challenge infection beside the necrotic strain from where the CP gene originated an ordinary strain PVY O/C was also applied (Wolf and Horváth, 2000).…”