Cloning and sequencing of potato virus Y coat protein gene from an Indian isolate and development of transgenic tobacco for PVY resistance

Potato virus Y (PVY) coat protein gene has been cloned from an Indian isolate of PVY. The coat protein gene from this isolate showed 93.2% nucleic acid sequence homology and more than 94% amino acid sequence homology compared to an American isolate. The coat protein gene has been sub-cloned into plant expression vector pBINPLUS and tobacco leaf discs were transformed using Agrobacterium tumefaciens. The transgenic tobacco plants analysed through PCR and Southern hybridization, confirmed the integration of coat protein gene into tobacco genome. The transgenic plants were hardened in the greenhouse and were mechanically infected with crude viral extract. The virus titre was analysed through ELISA and the transgenic plants showed less virus titre compared to non-transformed control plants. The cloned coat protein gene of PVY will be useful for imparting resistance against that virus in Indian potato cultivars.