Abstract:
Objective A polyclonal antibody of the plant viral protection-related RNA-binding protein suppressor of gene silencing 3 (SGS3) was prepared for detecting tomato spotted wilt virus (TSWV).
Methods The full-length coding sequence of NbSGS3 from Nicotiana benthamiana as well as its N-terminal truncated (622-1908bp) and C-terminal truncated (1-1365bp) mutants were cloned by RT-PCR. Prokaryotic expression vectors pET28a-NbSGS3 and mutant vectors were constructed. The recombinant proteins were induced to immunize New Zealand white rabbits to obtain the antiserum and determine reaction specificity. Changes in NbSGS3 protein and mRNA after infecting N. benthamiana with TSWV were verified by western blot and qRT-PCR using purified antibodies.
Results The recombinant proteins and truncated mutants of NbSGS3 were successfully secured. The prepared NbSGS3 polyclonal antibodies specifically recognized the prokaryotic expression and endogenous NbSGS3 in N. benthamiana. The western blot showed that the TSWV N protein could be specifically detected in the virus-infected plants, and the expression of NbSGS3 significantly higher than that in the healthy control. The qRT-PCR analysis indicated that the TSWV infection significantly up-regulated NbSGS3 (P<0.01), which was consistent with the expression changes.
Conclusion The successfully prepared NbSGS3 polyclonal antibodies could be adequately applied for immunological detection of the target proteins. TSWV-infected N. benthamiana displayed upregulated NbSGS3 mRNA and protein that positively confirmed the regulating function of the gene.