Development of transgenic cucumber mosaic virus (CMV) resistant gerbera plants expressing CMV coat protein gene.

Gerbera (Gerbera jamesonii L.) has its immense importance to the floriculture industry worldwide. The gerbera flower production has been hampered by various viruses, among them cucumber mosaic virus (CMV) has shown considerable damage. As natural resistance to CMV is absent in gerbera, here, we have made an attempt to develop transgenic gerbera plants expressing coat protein (CP) gene of CMV via Agrobacterium mediated transformation of base petiole explants for genetic resistance to CMV infection. Among the 44 putative transgenic gerbera plant acclimatized, 39 were found positive for integration of CP gene by polymerase chain reaction and southern hybridization assay using their specific primer and probe respectively. Northern hybridization assay using CP gene specific probe confirmed the transcription of transgene in all 39 transgenic plants. These plants showed translation of CP during DAS-ELISA when tested with antiserum specific to CP of CMV. These 39 plants when challenged by mechanical inoculations with CMV gerbera isolate showed virus resistance in 53% (21 out of 39) plants, virus tolerance (delayed mild symptom) in 33% (13/39) plants, while rest 12.8% (5/39) plants showed severe disease symptoms. The CP mediated resistance of CMV in transgenic gerbera is being reported for the first time from India. [ABSTRACT FROM AUTHOR]