Immunodiagnosis of groundnut and watermelon bud necrosis viruses using polyclonal antiserum to recombinant nucleocapsid protein of Groundnut bud necrosis virus

In vitro gene expression strategy was used for the production of polyclonal antiserum to the nucleocapsid protein (NP) of Groundnut bud necrosis virus (GBNV). The GBNV NP gene from cowpea isolate was cloned into 6x His-tagged UA cloning vector and expressed in Escherichia coli [M15] cells. The fusion protein was detected in insoluble fraction and was purified by using Ni-NTA agarose resin. The purified 6x His-fusion protein (32 kDa) was used for immunisation to produce a high titre polyclonal antiserum. The antiserum to the NP of GBNV at 1:4000 dilution detected successfully natural infection of GBNV and Watermelon bud necrosis virus in a wide range of cucurbitaceous, leguminous and solanaceous hosts from different locations.