Production of a polyclonal antiserum against recombinant nucleocapsid protein and its application for the detection of fig mosaic virus

Abstract

Mosaic disease (MD), caused by Fig mosaic emaravirus (FMV), is the most important and devastating virus disease of fig trees worldwide. The detection of FMV in infected plants is possible only through the use of molecular techniques, i.e. RT-PCR and LAMP, which both offer high sensitivity of detection, but are also considered laborious when dealing with a large number of samples. To cope with this restriction, a polyclonal antiserum through the immunization of a rabbit by injecting the recombinant nucleocapsid protein (NP) of FMV was raised and evaluated for its efficacy in Western Blot, Dot immuno-binding and DAS-ELISA. The results obtained showed that the raised antiserum was able to identify the nucleocapsid protein of FMV (p3) which was found to have an estimated molecular weight of ca. 35 KDa. In addition, the antiserum, when used in the three serological assays, was able to detect the p3 of FMV in protein extracts of infected plants with different levels of efficacy. Dot immuno-binding, using denatured plant protein extract, proved to be the most efficient serological assay for detecting FMV in samples collected from different fig orchards. This is the first report on an antiserum raised against FMV that could be used for immunological detection of the virus.