Expression of biologically active Hemagglutinin-neuraminidase protein of Peste des petits ruminants virus in transgenic pigeonpea [Cajanus cajan (L) Millsp.]

Hemagglutinin-neuraminidase (HN) gene of Peste des petits ruminants virus (PPRV) has been expressed in pigeonpea for the development of an edible vaccine for Peste des Petits ruminant (PPR). PPRV, causes PPR disease in sheep and goats with high mortality rate. The two surface glycoproteins of PPRV Hemagglutinin-neuraminidase and fusion protein (F) confer protective immunity. We report the successful generation of transgenic pigeonpea (Cajanus cajan (L.) Millsp.) plants and expression of HN protein having biological activity. A 2kb fragment containing the coding region of the HN gene from an Indian isolate was cloned into the binary vector pBI121 and mobilized into Agrobacterium tumefaciens strain GV3 101. Cotyledonary nodes from germinated seeds of pigeonpea were used for transformation. The presence of transgenes, NPTII and HN in the plants was confirmed by PCR. The expression of HN protein in the transgenic lines was further confirmed by Western blot analysis using polyclonal monospecific antibody to HN and more importantly plant-derived HN protein was shown to be biologically active as demonstrated by neuraminidase activity. Transgenic plants were fertile and PCR of T₁ plants confirmed the inheritance of the transgene.