Expression of hemagglutinin protein of Rinderpest virus in transgenic pigeon pea [Cajanus cajan (L.) Millsp.] plants

Rinderpest virus is the causative agent of a devastating, often fatal disease in wild and domestic bovids that is endemic in Africa, the Middle East and South Asia. The existing live attenuated vaccine is heat-labile, and thus there is a need for the development of new strategies for vaccination. This paper reports the development of transgenic pigeon pea [Cajanus cajun (L.) Millsp.] expressing one of the protective antigens, the hemagglutinin (H) protein of Rinderpest virus. A 2-kb fragment containing the coding region of the H protein was cloned into pBI121 and mobilized into Agrobacterium tumefaciens strain EHA105. Embryonic axes and cotyledonary nodes from germinated seeds of pigeon pea were used for transformation. The presence of the transgene in transgenic plants was confirmed by Southern blots, and the specific transcription of the marker gene in the plants was demonstrated by reverse transcription-polymerase chain reaction. Integration of the H gene into the pigeon pea genome was confirmed by Southern hybridization. The expression of the H protein in the transgenic lines was confirmed by Western blot analysis using a polyclonal monospecific antibody to the H protein. The highest level of expression of the hemagglutinin protein in leaves of pigeon pea was 0.49% of the total soluble protein. The transgenic plants were fertile and the transgene expressed in the progeny.